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1 LTC4063 4063fb standalone linear li-ion charger with micropower low dropout linear regulator charge current programmable up to 1a integrated 100ma adjustable low dropout linear regulator charges single cell li-ion batteries directly from usb port preset charge voltage with 0.35% accuracy no external mosfet, sense resistor or blocking diode needed thermal regulation maximizes charge rate without risk of overheating* adjustable ldo output voltage range: 1.2v to 4.2v programmable charge termination timer programmable charge current detection/termination smartstart tm prolongs battery life charge status output 35 a charger quiescent current in shutdown 15 a ldo quiescent current available in a low profile (0.75mm) 10-lead (3mm 3mm) dfn package handheld computers portable mp3 players digital cameras single cell li-ion battery charger with regulated 3v output (c/10 termination) the ltc 4063 is a standalone linear charger for single cell lithium-ion batteries with an adjustable low dropout linear regulator (ldo). the adjustable ldo regulates an output voltage between 1.2v to 4.2v at up to 100ma load current. when the input supply (wall adapter or usb supply) is removed, the ldo regulates the output voltage without interruption. the battery charger and ldo regulator can be enabled individually. no external sense resistor or external blocking diode is required for charging due to the internal mosfet architec- ture. internal thermal feedback regulates the charge cur- rent to maintain a constant die temperature during high power operation or high ambient temperature conditions. the float voltage is fixed at 4.2v and the charge current is programmed with an external resistor. charge termination methods include minimum charge current or maximum time. with power applied, the LTC4063 can be put into shutdown mode to reduce the supply current to 35 a and the battery drain current to less than 2 a. other features include smart recharge, undervoltage lock- out, ldo current limiting and a charge status pin to indicate when the charge cycle has completed. complete charge cycle (900mah battery) features descriptio u applicatio s u typical applicatio u + v cc timer prog idet bat out fb LTC4063 gnd 440k 700ma 160k 715 ? 2.2 f 1 f v in 4.3v to 8v 4063 ta01a v out 3v 4.2v single cell li-ion battery time (hours) 0 charge current (ma) battery voltage (v) 400 500 600 2 4063 ta01b 300 200 0 0.50 1 1.50 0.25 2.25 0.75 1.25 1.75 100 800 700 3.75 4.00 4.25 3.50 3.25 2.75 3.00 4.75 4.50 constant current constant voltage v cc = 5v t a = 25 c , lt, ltc and ltm are registered trademarks of linear technology corporation. smartstart is a trademark of linear technology corporation. all other trademarks are the property of their respective owners. *protected by u.s. patents including 6522118.
2 LTC4063 4063fb order part number (note 1) input supply voltage (v cc ) ....................... 0.3v to 10v chgen, ldoen, chrg ............................. 0.3v to 10v fb ............................................................... 0.3v to 8v prog, idet, timer ...................... 0.3v to v cc + 0.3v bat, out .................................................... ?.3v to 8v bat short-circuit duration .......................... continuous out short-circuit duration ......................... continuous bat pin current (note 8) .......................................... 1a maximum junction temperature (note 7) ........... 125 c operating temperature range (note 2) .. 40 c to 85 c storage temperature range ................. 65 c to 125 c LTC4063edd t jmax = 125 c, ja = 40 c/w (note 3) exposed pad (pin 11) is ground must be soldered to pcb absolute m axi m u m ratings w ww u package/order i n for m atio n w u u symbol parameter conditions min typ max units v cc v cc supply voltage 4.3 8 v i cc i cc supply current charge mode (note 4), r prog = 10k 400 800 a standby mode, charge terminated 100 200 a shutdown (chgen = 5v, v cc < v bat or v cc < v uv ) 35 65 a chgen = 5v and ldoen = 5v 15 30 a v float v bat regulated output voltage 4.185 4.2 4.215 v 0 c t a 85 c 4.170 4.2 4.230 v i bat bat pin current (note 5) r prog = 10k, constant-current mode 93 100 107 ma r prog = 1.25k, constant-current mode 760 800 840 ma standby mode, charge terminated 3.5 7 a shutdown mode (chgen = 5v, ldoen = 5v) 1 2 a v prog prog pin voltage r prog = 10k, constant-current mode 0.97 1 1.03 v r prog = 1.25k, constant-current mode 0.97 1 1.03 v v chrg chrg output low voltage i chrg = 5ma 0.35 0.6 v i trikl trickle charge current v bat < v trikl , r prog = 10k 6 10 14 ma v bat < v trikl , r prog = 1.25k 60 80 100 ma v trikl trickle charge threshold voltage v bat rising 2.8 2.9 3 v hysteresis 100 mv v uv v cc undervoltage lockout voltage from low to high 3.7 3.8 3.9 v hysteresis 200 mv v asd v cc ?v bat lockout threshold voltage v cc from low to high, v bat = 4.2v 145 180 220 mv v cc from high to low, v bat = 4.2v 10 45 75 mv v chgen chgen input threshold voltage chgen rising, 4.3v < v cc < 8v 0.4 0.7 1 v hysteresis 100 mv r chgen chgen pin pull-down resistor 1.2 2 5 m ? v ct charge termination mode threshold v timer from high to low 0.4 0.7 1 v voltage hysteresis 100 mv v ut user termination mode threshold voltage v timer from low to high 4.15 4.1 4.5 v hysteresis 100 mv the indicates the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. v cc = 5v, unless otherwise noted. top view 11 dd package 10-lead (3mm 3mm) plastic dfn 10 9 6 7 8 4 5 3 2 1 v cc prog idet timer chrg bat out fb ldoen chgen dd part marking lbhx electrical characteristics consult factory for parts specified with wider operating temperature ranges. order options tape and reel: add #tr lead free: add #pbf lead free tape and reel: add #trpbf lead free part marking: http://www.linear.com/leadfree/
3 LTC4063 4063fb symbol parameter conditions min typ max units i detect charge current detection threshold r det = 1k, 0 c t a 85 c 90 100 110 ma r det = 2k, 0 c t a 85 c 455055 ma r det = 10k, 0 c t a 85 c 8.5 10 11.5 ma r det = 20k, 0 c t a 85 c 456 ma ? v rechrg recharge threshold voltage v float ?v rechrg , 0 c t a 85 c 75 100 125 mv t term termination comparator filter time current termination mode 1 1.5 2.2 ms t rechrg recharge comparator filter time 3 7 14 ms t timer charge cycle time c timer = 0.1 f 2.55 3 3.45 hour t ss soft-start time i bat from 0 to i chg 100 s t lim junction temperature in constant 105 c temperature mode r on power fet ?n?resistance 375 m ? (between v cc and bat) v bat-ldo ldo supply voltage (bat) 2.65 4.4 v i bat-ldo ldo supply current (from bat) v cc < v bat , i out = 0ma 15 25 a v cc > v bat , i out = 0ma (note 6) 9 18 a i bat-ldo-sd ldo supply current in shutdown v bat = 4.4v 2.5 5 a v fb fb regulated voltage v bat = 3.7v, i out = 1ma 784 800 816 mv v fb(line) v fb line regulation v bat = 2.65v to 4.4v, i out = 1ma 14 mv v fb(load) v fb load regulation i out = 1ma to 100ma, v bat = 4.4v 14 mv v ldoen ldoen input threshold voltage (rising) ldoen rising, v bat = 4.4v 0.4 0.7 1 v hysteresis 100 mv r ldoen ldoen pin pull-down resistor 1.2 2 5 m ? v do ldo dropout voltage i out = 100ma, v out = 3v 125 200 mv v ldouvlo ldo undervoltage lockout threshold v bat from high to low 2.45 2.55 2.65 v hysteresis 100 mv i fb fb pin current ?5 0 25 na i sc short-circuit output current v out = 0v 500 ma v no(rms) output voltage noise v out = 3v, i out = 100ma, c out = 2.2 f, 135 v rms 10hz f 100khz the indicates the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. v cc = 5v, unless otherwise noted. electrical characteristics note 1: stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. exposure to any absolute maximum rating condition for extended periods may affect device reliability and lifetime. note 2: the LTC4063edd is guaranteed to meet performance specifica- tions from 0 c to 70 c. specifications over the 40 c to 85 c operating temperature range are assured by design, characterization and correlation with statistical process controls. note 3: failure to correctly solder the exposed pad of the package to the pc board will result in a thermal resistance much higher than 40 c/w. note 4: supply current includes prog pin current and idet pin current (approximately 100 a each) but does not include any current delivered to the battery through the bat pin (approximately 100ma). note 5: does not include ldo supply current. note 6: the ldo is partially powered from v cc , thus reducing the supply current from the bat pin. note 7: this ic includes overtemperature protection that is intended to protect the device during momentary overload conditions. overtemperature protection will become active at a junction temperature greater than the maximum operating temperature. continuous operation above the specified maximum operating junction temperature may impair device reliability. note 8: defined by long term current density limitations.
4 LTC4063 4063fb typical performance characteristics regulated output (float) voltage vs charge current temperature ( c) ?0 0.994 v prog (v) 0.996 0.998 1.000 1.002 1.006 ?5 02550 4063 g03 75 100 1.004 r prog = 10k v cc = 8v v cc = 4.3v regulated output (float) voltage vs temperature prog pin voltage vs temperature (constant-current mode) charge current vs prog pin voltage internal charge timer vs temperature chrg pin i-v curve v prog (v) 0 0 i bat (ma) 100 300 400 500 0.8 900 4063 g04 200 0.4 0.2 1.0 0.6 1.2 600 700 800 v cc = 5v r prog = 1.25k v timer = 5v temperature ( c) ?0 t timer (minutes) 185 190 195 25 75 4063 g05 180 175 ?5 0 50 100 125 170 165 c timer = 0.1 f v cc = 4.3v v cc = 8v v chrg (v) 0 20 25 35 4063 g06 15 10 12 467 5 0 30 35 i chrg (ma) v cc = 5v v bat = 4v t a = ?0 c t a = 90 c t a = 25 c trickle charge current vs temperature trickle charge threshold voltage vs temperature charge current vs battery voltage temperature ( c) ?0 90 88 86 84 82 80 78 76 25 75 4063 g07 ?5 0 50 100 i trikl (ma) v cc = 5v v bat = 2.5v r prog = 1.25k temperature ( c) ?0 2.84 v trikl (v) 2.86 2.88 2.90 2.92 2.96 ?5 02550 4063 g08 75 100 2.94 v cc = 5v r prog = 1.25k v bat (v) 2.7 0 i bat (ma) 200 400 600 800 1000 3 3.3 3.6 3.9 4063 g09 4.2 4.5 v cc = 5v r prog = 1.25k ja = 40 c/w temperature ( c) ?0 4.185 v float (v) 4.190 4.195 4.200 4.205 4.215 ?5 02550 4063 g02 75 100 4.210 r prog = 10k v cc = 8v v cc = 4.3v t a = 25 c unless otherwise noted. charge current (ma) 0 v float (v) 4.18 4.22 800 4063 g01 4.14 4.10 200 400 600 100 300 500 700 4.26 4.16 4.20 4.12 4.24 v cc = 5v r prog = 1.25k
5 LTC4063 4063fb typical performance characteristics charge current vs ambient temperature charge current vs supply voltage recharge threshold voltage vs temperature power fet on resistance vs temperature shutdown current vs temperature chgen pin threshold voltage (on-to-off) vs temperature chgen pin pull-down resistance vs temperature fb pin regulated voltage vs output current temperature ( c) 50 ?5 0 i bat (ma) 400 1000 0 50 75 4063 g10 200 800 600 25 100 125 r prog = 1.25k onset of thermal regulation r prog = 2k v cc = 5v v bat = 4v ja = 40 c/w temperature ( c) ?0 4.04 v rechrg (v) 4.06 4.08 4.10 4.12 4.16 ?5 02550 4063 g12 75 100 4.14 v cc = 4.3v v cc = 8v temperature ( c) ?0 70 60 50 40 30 20 10 0 25 75 4063 g14 ?5 0 50 100 i cc ( a) chgen = v cc ldoen = 0v v cc = 8v v cc = 5v v cc = 4.3v temperature ( c) ?0 3.0 2.8 2.6 2.4 2.2 2.0 1.8 1.6 25 75 4063 g16 ?5 0 50 100 r chgen (m ? ) i out (ma) 0 797 v fb (mv) 798 799 800 801 803 20 40 60 80 4063 g17 100 120 802 v bat = 4.2v t a = 25 c t a = 90 c t a = 115 c t a = ?0 c fb pin regulated voltage vs temperature temperature ( c) ?0 v fb (v) 801 802 803 25 75 4063 g18 800 799 ?5 0 50 100 125 798 797 i load = 1ma v bat = 4.2v v bat = 2.65v v cc (v) 4 300 i bat (ma) 400 500 600 700 56 7 8 4063 g11 800 900 4.5 5.5 6.5 7.5 r prog = 1.25k v bat = 3.3v ja = 35 c/w t a = 25 c onset of thermal regulation temperature ( c) ?0 r ds(on) (m ? ) 550 600 650 25 75 4063 g13 500 450 ?5 0 50 100 125 400 350 v bat = 4v i bat = 200ma r prog = 1.25k temperature ( c) ?0 v chgen (mv) 800 850 900 25 75 4063 g15 750 700 ?5 0 50 100 125 650 600 v cc = 5v
6 LTC4063 4063fb typical performance characteristics ldo regulator dropout voltage vs temperature ldo regulator quiescent current vs temperature ldo regulator 10hz to 100khz output noise ldoen pin threshold (on-to-off) vs temperature ldo regulator output noise spectral density ldo regulator transient response ldoen pin pull-down resistance vs temperature frequency (hz) 0.1 output noise spectral density ( v/ hz) 1 10 1k 10k 100k 4063 g24 0.01 100 10 temperature ( c) ?0 3.0 2.8 2.6 2.4 2.2 2.0 1.8 1.6 25 75 4063 g23 ?5 0 50 100 r ldoen (m ? ) temperature ( c) ?0 0 v dropout (mv) 50 100 150 200 ?5 0 25 50 4063 g19 75 100 v out = 3v i out = 100ma temperature ( c) ?0 i bat ( a) 15 20 25 75 4060 g20 10 5 0 ?5 025 50 100 v bat = 4.2v v bat = 2.65v temperature ( c) ?0 v ldoen (mv) 800 850 900 25 75 4063 g22 750 700 ?5 0 50 100 125 650 600 v bat = 4v output voltage deviation 50mv/div load current 50ma/div 4063 g28 50 s/div c out = 2.2 f v out = 1.2v v out 500 v/ div 4063 g21 135 v rms 10ms/div c out = 2.2 f i load = 100ma v out = 3v ldo regulator dropout voltage vs load current load current (ma) 0 0 v dropout (mv) 30 60 90 120 180 20 40 60 80 4063 g26 100 120 150 v out = 3v t a = 115 c t a = 90 c t a = 40 c t a = 25 c
7 LTC4063 4063fb uu u pi fu ctio s bat (pin 1): charger output and regulator input. this pin provides charge current to the battery and regulates the final float voltage to 4.2v. this pin also supplies power to the ldo regulator. out (pin 2): ldo regulator output. this pin should be bypassed with a 2 f low esr capacitor as close to the pin as possible for best performance. the minimum v out is 1.2v. fb (pin 3): regulator feedback input. the voltage on this pin is compared to the internal reference voltage (800mv) by the error amplifier to keep the output voltage in regula- tion. an external resistor divider between out and fb sets the output voltage. ldoen (pin 4): ldo enable input. a logic high on the ldoen pin shuts down the ldo. in this state, out becomes high impedance and the battery drain current drops to less than 5 a. a logic low on the ldoen pin enables the ldo regulator. a 2m pull-down resistor de- faults the ldo to its enabled state. chgen (pin 5): charger enable input. a logic high on the chgen pin places the charger into shutdown mode, where the i cc quiescent current is less than 65 a. a logic low on this pin enables battery charging. a 2m pull-down resistor to ground defaults the charger to its enabled state. chrg (pin 6): open-drain charge status output. the charge status indicator pin has two states: pull-down and high impedance. this output can be used as a logic interface or an led driver. in the pull-down state, an nmos transistor capable of sinking 10ma pulls down on the chrg pin. the state of this pin is dependent on the value of i detect as well as the termination method being used. see applications information. timer (pin 7): timer program and termination select pin. this pin selects which method is used to terminate the charge cycle. connecting a capacitor, c timer , to ground selects charge time termination. the charge time is set by the following formula: time hours hours c f or cf time hours hours timer timer () . . () () = = 3 01 01 3 connecting the pin to ground selects charge current termination, while connecting the pin to v cc selects user termination. see applications information. idet (pin 8): current detection threshold program pin. the current detection threshold, i detect , is set by con- necting a resistor, r det , to ground. i detect is set by the following formula: i r r i v r or r v i detect prog det chg det det detect == = 10 100 100 the chrg pin becomes high impedance when the charge current drops below i detect . i detect can be set to 1/10th the programmed charge current by connecting idet di- rectly to prog. see applications information. this pin is clamped to approximately 2.4v. driving this pin to voltages beyond the clamp voltage can draw large currents and should be avoided. prog (pin 9): charge current program and charge cur- rent monitor. the charge current is set by connecting a resistor, r prog , to ground. when charging in constant current mode, this pin servos to 1v. the voltage on this pin can be used to measure the charge current using the following formula: i v r bat prog prog = 1000 v cc (pin 10): positive input supply pin. provides power to the battery charger. this pin should be bypassed with a 1 f capacitor. exposed pad (pin 11): ground. this pin is the back of the exposed pad package and must be soldered to the pcb copper for minimal thermal resistance.
8 LTC4063 4063fb block diagra w + + + + 11 9 8 7 2 ca ma 1.2v 800mv 2.9v prog idet r det c timer r prog 0.1v to bat 1v 3 a 0.1v + + c3 c2 logic v cc t a t die 105 c shdn 4063 bd gnd + va ra r1 r2 bat 1000 1 1 v cc out 3 fb 1 10 term rechrg 4.1v to bat chgen 2m ? sel timer counter oscillator chgen ldoen ldoen stop chrg 2m ? 6 4 5 + c1
9 LTC4063 4063fb operatio u the LTC4063 is designed to charge a single cell lithium- ion battery and supply a regulated output voltage for bat- tery-powered applications. using the constant current/con- stant voltage algorithm, the charger can deliver up to 1a of charge current with a final float voltage accuracy of 0.35%. the LTC4063 includes an internal p-channel power mosfet and thermal regulation circuitry. no blocking diode or external sense resistor is required; thus, the basic charger circuit requires only two external components. the ldo regulator is powered from the battery terminal and can be programmed for output voltages between 1.2v and 4.2v using external resistors. an output capaci- tor is required on the out pin for stability and improved transient response. a low esr capacitor of 2 f should be used. normal operation the charge cycle begins when the voltage at the v cc pin rises above the uvlo level and a discharged battery is connected to bat. if the bat pin voltage is below 2.9v, the charger enters trickle charge mode. in this mode, the LTC4063 supplies 1/10th of the programmed charge current in order to bring the battery voltage up to a safe level for full current charging. once the bat pin voltage rises above 2.9v, the charger enters constant-current mode where the programmed charge current is supplied to the battery. when the bat pin approaches the final float voltage (4.2v), the LTC4063 enters constant-voltage mode and the charge current decreases as the battery becomes fully charged. the LTC4063 offers several methods with which to termi- nate a charge cycle. connecting an external capacitor to the timer pin activates an internal timer that stops the charge cycle after the programmed time period has elapsed. grounding the timer pin and connecting a resistor to the idet pin causes the charge cycle to terminate once the charge current falls below a set threshold when the charger is in constant-voltage mode. connecting the timer pin to v cc disables internal termi- nation, allowing external charge termination to be used by the chgen input. see applications information for more on charge termination methods. programming the charge current the charge current is programmed using a single resistor from the prog pin to ground. the battery charge current is 1000 times the current out of the prog pin. the program resistor and the charge current are calculated by the following equations: r v i i v r prog chg chg prog == 1000 1000 , the charge current out of the bat pin can be determined at any time by monitoring the prog pin voltage and applying the following equation: i v r bat prog prog = 1000 smartstart when the LTC4063 is initially powered on or brought out of shutdown mode, the charger checks the voltage on bat. if the bat pin is below the recharge threshold of 4.1v (which corresponds to approximately 80% to 90% battery capacity), the LTC4063 enters charge mode and begins a full charge cycle. if the bat pin is above 4.1v, the LTC4063 enters standby mode and does not begin charging. this feature reduces the number of unnecessary charge cycles, prolonging battery life. automatic recharge when the charger is in standby mode, the LTC4063 continuously monitors the voltage on the bat pin. when the bat pin voltage drops below 4.1v, the charge cycle is automatically restarted and the internal timer is reset to 50% the programmed charge time (if time termination is being used). this feature eliminates the need for periodic charge cycle initiations and ensures that the battery is always fully charged. automatic recharge is disabled in user termination mode. thermal regulation an internal thermal feedback loop reduces the programmed charge current if the die temperature attempts to rise above a preset value of approximately 105 c. this feature
10 LTC4063 4063fb protects the LTC4063 from excessive temperature and allows the user to push the limits of the power handling capability of a given circuit board without risk of damaging the LTC4063. the charge current can be set according to typical (not worst-case) ambient temperatures with the assurance that the charger will automatically reduce the current in worst-case conditions. undervoltage lockout (uvlo) an internal undervoltage lockout circuit monitors the input voltage and keeps the charger in shutdown mode until v cc rises above the undervoltage lockout threshold (3.8v). the uvlo circuit has a built-in hysteresis of 200mv. furthermore, to protect against reverse current in the power mosfet, the uvlo circuit keeps the charger in shutdown mode if v cc falls to less than 45mv above the battery voltage. hysteresis of 135mv prevents the charger from cycling in and out of shutdown. manual shutdown at any point in the charge cycle, the charger can be put into shutdown mode by pulling the chgen pin high. this reduces the supply current to less than 65 a and the battery drain current of the charger to less than 2 a. a new charge cycle can be initiated by pulling the chgen pin low. pulling the ldoen pin high puts the ldo into shutdown mode reducing the battery drain current of the ldo to less than 5 a. when both the chgen and ldoen pins are pulled high, the total battery drain current from the LTC4063 is less than 2 a. if shutdown is not required, leaving these pins disconnected continuously enables the circuit. trickle charge and defective battery detection when the bat pin voltage is below the 2.9v trickle charge threshold (v trikl ), the charger reduces the charge current to 10% of the programmed value. if the battery remains in trickle charge for more than 25% of the total programmed charge time, the charger stops charging and enters a fault state, indicating that the battery is defective. 1 the LTC4063 indicates the fault state by driving the chrg open-drain output with a square wave. the duty cycle of this oscillation is 50% and the frequency is set by c timer : f f c hz chrg timer = 01 31 . ? an led driven by the chrg output exhibits a blinking pattern, indicating to the user that the battery needs replacing. to exit the fault state, the charger must be restarted either by toggling the chgen input or removing and reapplying power to v cc. charge status output (chrg) the charge status indicator pin has two states: pull-down and high impedance. in the pull-down state, an nmos transistor pulls down on the chrg pin and can sink up to 10ma. a pull-down state indicates that the LTC4063 is charging a battery and the charge current is greater than i detect (which is set by the external resistor r det ). a high impedance state indicates that the charge current has dropped below i detect . in the case where the idet pin is left open (r det = , i detect = 0), a high impedance state on chrg indicates that the LTC4063 is not charging. low dropout linear regulator (ldo) the out pin provides a stable, regulated output voltage powered from the battery. this output can power devices such as memory or usb controllers from the battery when there is no power applied to v cc . the ldo can deliver 100ma of current with a nominal dropout voltage of 150mv. it is designed to be stable with a low esr capacitor greater than 2 f on the out pin. furthermore, the ldo is capable of operating from a li-ion battery voltage as low as 2.65v with less than 300mv of dropout over the specified operating conditions. an und- ervoltage lockout circuit automatically disables the ldo when the battery voltage drops below 2.55v, reducing the battery drain current to less than 5 a. the ldo can be dis- abled by pulling the ldoen pin high, reducing the battery quiescent current to less than 5 a. operatio u 1 the defective battery detection feature is only available when time termination is being used.
11 LTC4063 4063fb figure 1 shows how an external resistor divider sets the regulator output voltage. the output voltage can be set operatio u figure 1. adjustable linear regulator applicatio s i for atio wu uu programming charge termination the LTC4063 terminates a charge cycle using several methods, allowing the designer considerable flexibility in choosing an ideal charge termination algorithm. table 1 shows a brief description of the different termination methods and their behavior. charge time termination connecting a capacitor (c timer ) to the timer pin enables the timer and selects charge time termination. the total charge time is set by: time hours f c hours timer () . = 01 3 method charge time termination charge current termination timer 0.1 f to gnd i det r det to gnd charger description charges for 3 hours. after 3 hours, the charger stops charging and enters standby mode. recharge cycles last for 1.5 hours charges for 3 hours. after 3 hours, the charger stops charging and enters standby mode. recharge cycles last for 1.5 hours charges until charge current drops below i detect , then enters standby mode pull-down state when charging. high impedance state when charging is stopped pull-down state when charging. high impedance state when charging is stopped chrg output description pull-down state while i bat > i detect . high impedance state while i bat < i detect or when charging is stopped pull-down state while i bat > i detect . high impedance state while i bat < i detect or when charging is stopped 0.1 f to gnd gnd r det to gnd user-selectable charge termination v cc r det to gnd charges indefinitely until chgen pin is pulled high v cc nc pull-down state when charging. high impedance state when charging is stopped pull-down state when charging. high impedance state when charging is stopped gnd nc nc charges indefinitely until chgen pin is pulled high. smartstart is disabled charges indefinitely until chgen pin is pulled high. smartstart is disabled table 1 when the programmed time has elapsed, the charge cycle terminates and the charger enters standby mode. subse- quent recharge cycles terminate when half the programmed time has elapsed. the idet pin determines the behavior of the chrg output. connecting a resistor (r det ) from the idet pin to ground sets the charge current detection threshold, i detect : i r r i v r or r v i detect prog det chg det det detect == = 10 100 100 anywhere between 1.2v and 4.2v, although the upper limit is limited by the battery voltage minus the regulator dropout voltage. vmv r r out =+ ? ? ? ? ? ? 800 1 2 1 in order to maintain stability under light load conditions, the maximum recommended value of r1 is 160k. + bat r2 c out single cell li-ion battery v out r1 4063 f01 out fb LTC4063 gnd
12 LTC4063 4063fb when the charge current (i bat ) is greater than i detect , the chrg output is in its pull-down state. when the charger enters constant-voltage mode operation and the charge current falls below i detect , the chrg output becomes high impedance, indicating that the battery is almost fully charged. the chrg output will also become high impedance once the charge time elapses. if the idet pin is not connected, the chrg output remains in its pull- down state until the charge time elapses and terminates the charge cycle. figure 2 shows a charger circuit using charge time termi- nation that is programmed to charge at 500ma. once the charge current drops below 100ma in constant-voltage mode (as set by r det ), the chrg output turns off the led. this indicates to the user that the battery is almost fully charged and ready to use. the LTC4063 continues to charge the battery until the internal timer reaches 3 hours (as set by c timer ). during recharge cycles, the LTC4063 charges the battery until the internal timer reaches 1.5 hours. figure 3 describes the operation of the LTC4063 charger when charge time termination is used. + v cc chrg prog idet c timer 0.1 f v in 4063 f02 bat 500ma timer r det 1k r prog 2k LTC4063 gnd charge mode full current chrg state: pull-down if i bat > i detect hi-z if i bat < i detect charge time elapses 1/4 charge time elapses bat < 4.1v 4063 f03 trickle charge mode 1/10 full current bat > 2.9v bat < 2.9v 2.9v < bat < 4.1v bat > 4.1v chgen = 5v or uvlo condition standby mode no charge current chrg state: hi-z shutdown mode i cc drops to 35 a chrg state: hi-z chrg state: pull-down fault mode no charge current chrg state: square wave recharge mode full current chrg state: pull-down if i bat > i detect hi-z if i bat < i detect 1/2 charge time elapses power on chgen = 0v or uvlo condition stops figure 2. charge time termination. the charger automatically shuts off after 3 hours figure 3. state diagram of a charge cycle using charge time termination applicatio s i for atio wu uu
13 LTC4063 4063fb charge current termination connecting the timer pin to ground selects charge current termination. with this method, the timer is disabled and a resistor (r det ) must be connected from the idet pin to ground. i detect is programmed using the same equation stated in the previous section (repeated here for convenience): i r r i v r or r v i detect prog det chg det det detect == = 10 100 100 the charge cycle terminates when the charge current falls below i detect . this condition is detected using an inter- nal, filtered comparator to monitor the idet pin. when the idet pin falls below 100mv for longer than t term (typi- cally 1.5ms), charging is terminated. when charging, transient loads on the bat pin can cause the idet pin to fall below 100mv for short periods of time before the dc current has dropped below the i detect threshold. the 1.5ms filter time (t term ) on the internal comparator ensures that transient loads of this nature do not result in premature charge cycle termination. once the average charge current drops below i detect , the charger terminates the charge cycle. the chrg output is in its pull-down state when charging and in its high impedance state once charging has stopped. figure 4 describes the operation of the LTC4063 charger when charge current termination is used. user-selectable charge termination connecting the timer pin to v cc selects user-selectable charge termination, in which all internal termination features are disabled. the charge cycle continues indefi- nitely until the charger is shut down through the chgen pin. the idet pin programs the behavior of the chrg output in the same manner as when using charge time termination. specifically, when the charge current (i bat ) is greater than i detect , the chrg output is in its pull-down state. when the charger enters constant-voltage mode operation and the charge current falls below i detect , the chrg output becomes high impedance, indicating that the battery is charged. if the idet pin is not connected, the chrg output remains in its pull-down state until the charger is shut down. applicatio s i for atio wu uu charge mode full current i bat < i detect in voltage mode 4063 f04 trickle charge mode 1/10 full current bat > 2.9v bat < 2.9v 2.9v < bat < 4.1v bat > 4.1v bat < 4.1v chgen = 5v or uvlo condition standby mode no charge current chrg state: hi-z shutdown mode i cc drops to 35 a chrg state: hi-z chrg state: pull-down chrg state: pull-down power on chgen = 0v or uvlo condition stops figure 4. state diagram of a charge cycle using charge current termination
14 LTC4063 4063fb with user-selectable charge termination, the smartstart feature is disabled; when the charger is powered on or enabled, the LTC4063 automatically begins charging, re- gardless of the battery voltage. figure 5 describes charger operation when user-selectable charge termination is used. programming c/10 current detection/termination in most cases, an external resistor, r det , is needed to set the charge current detection threshold, i detect . however, when setting i detect to be 1/10th of i chg , the idet pin can be connected directly to the prog pin. this reduces the component count, as shown in figure 6. when prog and idet are connected in this way, the full- scale charge current, i chg , is programmed using a differ- ent equation: r v i i v r prog chg chg prog == 500 500 , stability considerations the battery charger constant voltage mode feedback loop is stable without any compensation provided a battery is connected. however, a 1 f capacitor with a 1 ? series resistor to gnd is recommended at the bat pin to keep ripple voltage low when the battery is disconnected. when the charger is in constant current mode, the prog pin is in the feedback loop, not the battery. the constant current stability is affected by the impedance at the prog pin. with no additional capacitance on the prog pin, the charger is stable with program resistor values as high as 10k; however, additional capacitance on this node reduces the maximum allowed program resistor. for the ldo regulator, a capacitor (c out ) must be con- nected from out to gnd to ensure regulator loop stability. it is recommended that low esr capacitors be used for c out to reduce noise on the output of the linear regulator. c out must be 2 f for best performance. applicatio s i for atio wu uu charge mode full current 4063 f05 trickle charge mode 1/10 full current bat > 2.9v bat < 2.9v 2.9v < bat chgen = 5v or uvlo condition shutdown mode i cc drops to 35 a chrg state: hi-z chrg state: pull-down power on chgen = 0v or uvlo condition stops chrg state: pull-down if i bat > i detect hi-z if i bat < i detect figure 5. state diagram of a charger cycle using user termination + v cc prog idet v in bat 500ma timer r det 2k r prog 2k LTC4063 gnd + v cc prog idet v in 4063 f06 bat 500ma timer r prog 1k LTC4063 gnd figure 6. two circuits that charge at 500ma full-scale current and terminate at 50ma
15 LTC4063 4063fb applicatio s i for atio wu uu regulator output noise noise measurements on the output should be made with care to ensure accurate results. coaxial connections and proper shielding should be used to maintain measurement integrity. figure 7 shows a test setup for taking the measurement. when the output is set to 3v and a 100ma load is applied, the LTC4063 output noise power in the 10hz to 100khz band is typically measured to be 135 v rms . for more information on obtaining accurate noise mea- surements for ldos, see application note 83. power dissipation when designing the battery charger circuit, it is not necessary to design for worst-case power dissipation scenarios because the LTC4063 automatically reduces the charge current during high power conditions. the condi- tions that cause the LTC4063 to reduce charge current through thermal feedback can be approximated by con- sidering the power dissipated in the ic. most of the power dissipation is generated from the internal charger mosfet (the ldo generates considerably less heat in most appli- cations). thus, the power dissipation is calculated to be approximately: p d = (v cc ?v bat ) ?i bat p d is the power dissipated, v cc is the input supply voltage, v bat is the battery voltage and i bat is the charge current. the approximate ambient temperature at which the ther- mal feedback begins to protect the ic is: t a = 105 c ?p d ? ja t a = 105 c ?(v cc ?v bat ) ?i bat ? ja example: an LTC4063 operating from a 5v wall adapter is programmed to supply 800ma full-scale current to a discharged li-ion battery with a voltage of 3.3v. assuming ja is 40 c/w (see thermal considerations), the ambient temperature at which the LTC4063 will begin to reduce the charge current is approximately: t a = 105 c ?(5v ?3.3v) ?(800ma) ?40 c/w t a = 105 c ?1.36w ?40 c/w = 105 c ?54.4 c t a = 50.6 c the LTC4063 can be used above 50.6 c ambient, but the charge current will be reduced from 800ma. the approxi- mate current at a given ambient temperature can be approximated by: i ct vv bat a cc bat ja = () 105 c, the charge current will be reduced to approximately: i cc vv cw c ca ima bat bat = () = = 105 60 533 40 45 68 662 ? / / it is important to remember that LTC4063 applications do not need to be designed for worst-case thermal conditions, since the ic will automatically reduce power dissipation when the junction temperature reaches ap- proximately 105 c. 5hz single order highpass in 10hz to 100khz 4063 f07 gain = 60db 10hz 2nd order butterworth hp 100khz 4th order butterworth lp 5hz single order highpass figure 7. filter structure for noise testing ldos
16 LTC4063 4063fb applicatio s i for atio wu uu protection features while the thermally regulated charger limits the junction temperature to 105 c during normal operation, current overload at the ldo regulator output may result in exces- sive power dissipation. internal circuitry limits the output currents, allowing the battery charger and regulator to be short-circuited to ground indefinitely. furthermore, if the junction temperature exceeds 150 c, both the battery charger and regulator will shut down. the LTC4063 be- comes enabled again once the junction temperature drops below 140 c. if the fault condition remains in place, the part will thermal cycle between the shutdown and enabled states. the LTC4063 also protects against reverse conduction from the ldo output to the battery input. this provides protection if a discharged (low voltage) battery is power- ing the ldo, and the output voltage is held above the battery voltage by a backup battery or a second regulator circuit. when the output voltage is higher than the battery voltage, the reverse output current is typically less than 50 a. thermal considerations in order to deliver maximum charge current under all conditions, it is critical that the exposed metal pad on the backside of the LTC4063 package is properly soldered to the pc board ground. correctly soldered to a 2500mm 2 double sided 1oz copper board, the LTC4063 has a ther- mal resistance of approximately 40 c/w. failure to make thermal contact between the exposed pad on the backside of the package and the copper board will result in thermal resistances far greater than 40 c/w. as an example, a correctly soldered LTC4063 can deliver over 800ma to a battery from a 5v supply at room temperature. without a good backside thermal connection this number would drop to much less than 500ma. v cc bypass capacitor many types of capacitors can be used for input bypassing, however, caution must be exercised when using multi- layer ceramic capacitors. because of the self-resonant and high q characteristics of some types of ceramic capaci- tors, high voltage transients can be generated under some start-up conditions such as connecting the charger input to a live power source. adding a 1.5 ? resistor in series with an x5r ceramic capacitor will minimize start-up voltage transients. for more information, see application note 88. charge current soft-start and soft-stop the LTC4063 includes a soft-start circuit to minimize the inrush current at the start of a charge cycle. when a charge cycle is initiated, the charge current ramps from zero to the full-scale current over a period of approximately 100 s. likewise, internal circuitry slowly ramps the charge cur- rent from full-scale to zero when the charger is shut down or self terminates. this has the effect of minimizing the transient current load on the power supply during start-up and charge termination. reverse polarity input voltage protection in some applications, protection from reverse polarity voltage on v cc is desired. if the supply voltage is high enough, a series blocking diode can be used. in other cases where the voltage drop must be kept low, a p-channel mosfet can be used (as shown in figure 8). figure 8. low loss input reverse polarity protection v cc v in 4063 f08 LTC4063 drain-bulk diode of fet
17 LTC4063 4063fb figure 9. combining wall adapter and usb power usb and wall adapter power the LTC4063 allows charging from both a wall adapter and a usb port. figure 9 shows how to combine wall adapter and usb power inputs. a p-channel mosfet, mp1, is used to prevent back conducting into the usb port when a wall adapter is present and a schottky diode, d1, is used to prevent usb power loss through the 1k pull- down resistor. most wall adapters can supply more current than the 500ma limited usb port. therefore, an n-channel mosfet, mn1, and an extra 3.3k program resistor are used to increase the charge current to 800ma when the wall adapter is present. applicatio s i for atio wu uu + v cc d1 prog idet gnd 3.3k 2k mn1 5v wall adapter i chg = 800ma usb power i chg = 500ma mp1 4063 f09 bat LTC4063 1.25k li-ion battery system load 1k
18 LTC4063 4063fb typical applicatio s u usb/wall adapter power li-ion charger (using charge current termination) + v cc timer bat prog idet LTC4063 gnd 2k 1 f 1k 11 8 9 1 10 7 10k 2.5k c 5v wall adapter usb power 4063 ta03 li-ion cell 100ma/ 500ma + chrg timer prog idet 6 7 9 8 bat out fb 1 2 3 LTC4063 gnd 340k 800ma 160k 11 625 ? 1.25k 1k 10 2.2 f 1 f 0.1 f v in 5v 4063 ta02 v out 2.5v single cell li-ion battery v cc full-featured li-ion charger with 2.5v regulated output (using charge time termination)
19 LTC4063 4063fb u package descriptio dd package 10-lead plastic dfn (3mm 3mm) (reference ltc dwg # 05-08-1699) 3.00 0.10 (4 sides) note: 1. drawing to be made a jedec package outline m0-229 variation of (weed-2). check the ltc website data sheet for current status of variation assignment 2. drawing not to scale 3. all dimensions are in millimeters 4. dimensions of exposed pad on bottom of package do not include mold flash. mold flash, if present, shall not exceed 0.15mm on any side 5. exposed pad shall be solder plated 6. shaded area is only a reference for pin 1 location on the top and bottom of package 0.38 0.10 bottom view?xposed pad 1.65 0.10 (2 sides) 0.75 0.05 r = 0.115 typ 2.38 0.10 (2 sides) 1 5 10 6 pin 1 top mark (see note 6) 0.200 ref 0.00 ?0.05 (dd10) dfn 1103 0.25 0.05 2.38 0.05 (2 sides) recommended solder pad pitch and dimensions 1.65 0.05 (2 sides) 2.15 0.05 0.50 bsc 0.675 0.05 3.50 0.05 package outline 0.25 0.05 0.50 bsc information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
20 LTC4063 4063fb ? linear technology corporation 2004 lt/lwi 0906 rev b ?printed in usa related parts linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com part number description comments battery chargers ltc1733 monolithic lithium-ion linear battery charger standalone charger with programmable timer, up to 1.5a charge current ltc1734 lithium-ion linear battery charger in thinsot tm simple thinsot charger, no blocking diode, no sense resistor needed ltc1734l lithium-ion linear battery charger in thinsot low current version of ltc1734; 50ma i chrg 180ma ltc4002 switch mode lithium-ion battery charger standalone, 4.7v v in 24v, 500khz frequency, 3 hour charge termination ltc4050 lithium-ion linear battery charger controller features preset voltages, c/10 charger detection and programmable timer, input power good indication, thermistor interface ltc4052 monolithic lithium-ion battery pulse charger no blocking diode or external power fet required, 1.5a charge current ltc4053 usb compatible monolithic li-ion battery charger standalone charger with programmable timer, up to 1.25a charge current ltc4054 standalone linear li-ion battery charger thermal regulation prevents overheating, c/10 termination, with integrated pass transistor in thinsot c/10 indicator, up to 800ma charge current ltc4057 lithium-ion linear battery charger up to 800ma charge current, thermal regulation, thinsot package ltc4058 standalone 950ma lithium-ion charger in dfn c/10 charge termination, battery kelvin sensing, 7% charge accuracy ltc4059 900ma linear lithium-ion battery charger 2mm 2mm dfn package, thermal regulation, charge current monitor output ltc4060 nimh/nicd standalone battery charger 1-/4-cell series batteries, no microcontroller, no firmware required, termination by ?v, max voltage or max time, up to 2a charge current ltc4411/ltc4412 low loss powerpath tm controller in thinsot automatic switching between dc sources, load sharing, replaces oring diodes power management ltc3405/ltc3405a 300ma (i out ), 1.5mhz, synchronous step-down 95% efficiency, v in = 2.7v to 6v, v out = 0.8v, i q = 20 a, i sd < 1 a, dc/dc converter thinsot package ltc3406/ltc3406a 600ma (i out ), 1.5mhz, synchronous step-down 95% efficiency, v in = 2.5v to 5.5v, v out = 0.6v, i q = 20 a, i sd < 1 a, dc/dc converter thinsot package ltc3411 1.25a (i out ), 4mhz, synchronous step-down 95% efficiency, v in = 2.5v to 5.5v, v out = 0.8v, i q = 60 a, i sd < 1 a, dc/dc converter ms package ltc3440 600ma (i out ), 2mhz, synchronous buck-boost 95% efficiency, v in = 2.5v to 5.5v, v out = 2.5v, i q = 25 a, i sd < 1 a, dc/dc converter ms package thinsot and powerpath are trademarks of linear technology corporation.

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