www.fairchildsemi.com rev. 1.0.4 12/12/02 features ldo with integrated microprocessor reset control low supply current (70? typ) ultra-low dropout voltage (0.9mv/ma) guaranteed 350ma output output voltage range from 1.3v to 6.2v bypass input capacitor for low noise operation active low or active high or open drain reset output 150msec guaranteed minimum reset output with no external components factory programmable v th for voltage detector from 1.5v to 4.8v msop-8 and 3x3 mlp-8 package applications battery-operated systems portable computers computers & printers, controllers critical microprocessor power monitoring intelligent instruments pagers general description the fan2591 family of low supply current and high- precision ldos feature very low dropout voltage, delayed microprocessor reset circuitry without external components, and continuous 350ma load current capability. an external bypass capacitor can be added to reduce the output noise of the fixed output version. voltage detector input, v det , and power supply input v in can be connected together. in this case, the rst output can be used for low battery detection, otherwise the v det input can be used independently from v in , in order to detect any voltage threshold within the factory programmable range (1.5v to 4.8v). the fan2591 incorporates both over-temperature and over-current protection. output is stable with 22? or more, tantalum capacitor. the fan2591 is available in space saving msop-8 and 3x3 mlp-8 packages. block diagram v ref current limit and thermal protection enable en reset generator rst v det v th select in out fan2591 350ma cmos ldo with shutdown, bypass and independent voltage detector with delayed reset output
fan2591 2 rev. 1.0.4 12/12/02 pin con?uration, top view pin de?itions pin assignments pin name pin function description rst reset output. active ??or active ??or ?pen drain vout regulated voltage output. gnd ground connection. cnoise reference voltage bypass input. en chip enable input. the regulator is fully enabled when a logic h is applied to this input.the regulator enters into shutdown mode when logic l is applied to this input. during shutdown, the regulator output falls to zero, rst output goes high and the supply current is reduced below 10 a, if there is no voltage applied to vdet. nc not connected. vin power supply input. vdet voltage detector input. vdet and vin can be connected together to detect low power supply voltage. fb input to set the adjustable output voltage. do not connect a capacitor to this pin. pin number fan2591 fixed output voltage fan2591 adjustable output voltage 1 rst rst 2 vout vout 3 gnd fb 4 cnoise gnd 5en en 6nc nc 7 vin vin 8 vdet vdet 8 lead mlp 3x3 msop-8 fan2591 fixed 1 2 3 4 8 7 6 5 rst vout gnd cnoise vdet vin nc en fan2591 fixed 1 2 3 4 8 7 6 5 rst vout gnd cnoise vdet vin nc en 8 lead mlp 3x3 msop-8 fan2591 adj 1 2 3 4 8 7 6 5 rst vout fb gnd vdet vin nc en fan2591 adj 1 2 3 4 8 7 6 5 rst vout fb gnd vdet vin nc en
fan2591 rev. 1.0.4 12/12/02 3 absolute maximum ratings absolute maximum ratings are the values beyond which the device may be damaged or have its useful life impaired. functional operation under these conditions is not implied. recommended operating conditions figure 1. test circuit for fixed output version figure 2. test circuit for adj output version parameter min. max. units supply voltage, v in to gnd 7 v voltage on any other pin -0.3 v in + 0.3 v junction temperature (t j ) 55 150 c storage temperature 65 150 c lead soldering temperature, 5 seconds 260 c electrostatic discharge protection (human body model) 4 kv parameter conditions min typ max units supply voltage, v in v out + v do v out + 1 6.5 v load current t j < 150 c 350 ma ambient operating temperature 40 +85 c fan2591 v out gnd c bypass nc rst v in en v det + - battery 5 6 7 8 4 3 2 1 rst 470pf (optional) + c1 22 f tantalum on off c2 10 f (optional) v out c bypass v det fan2591 v out fb gnd nc rst v in en v det + - battery 5 6 7 8 4 3 2 r1 r2 1 rst + c1 22 f tantalum on off c2 10 f (optional) v out v det
fan2591 4 rev. 1.0.4 12/12/02 electrical speci cations (v in = v out + 1v, i out = 0.1ma, v in = v en , and t a = +25 c, using circuit in figure 1 or figure 2, unless otherwise speci ed) notes: 1. v nom and v thnom are the nominal output and threshold voltages, selected by the customer, respectively. for specific fixed voltages please refer to the table ordering information, on the last page of this data sheet. custom fixed voltages, not listed in the table, are also available on request. 2. dropout voltage is defined as the input to output differential at which the output voltage drops to 1% below the value measur ed at 1v input output differential. symbol parameter conditions min typ max unit v out output voltage (note 1) -40 c t a 85 c 0.97v nom v nom 1.03v nom v v th threshold voltage (note 1) rst changes logic status 0.95v th nom v th nom 1.05v th nom v ? v out ? v in x v out line regulation v in = (v out + 1) to v in = 6.5v 0.1 0.4 % / v ? v out v out load regulation i out = 1 to 350ma 0.1 0.3 % v do dropout voltage (note 2) i out = 350ma 300 350 mv v fb feedback voltage (adj) i fb < 10 na 1.19 1.235 1.26 v i gnd ground current i out = 0 70 80 a i out = 350ma 70 80 a i sd shut-down current v en = 0 10 14 a i sc output short circuit current v out = 0 1.2 a peak enable input v el logic low voltage 0.7 v v eh logic high voltage 1.7 v i eh input current high v en = v in 10 a i el input current low v en = 0 0.01 a voltage detector input i vdh input current high v det = 5.5v 1.9 3 a i vdl input current low v det = 1.5v 0.5 1 a rst output i oh current sourced high active low or high v rst = v in 1.5v rst = high 3 4.5 6 ma i leak leakage current open drain v rst = 6.5v v det > v th 2a i ol current sinked low v rst = 0.5v rst = low 3 3.5 5 ma t r reset timeout period v det < v th 150 200 250 ms
fan2591 rev. 1.0.4 12/12/02 5 typical characteristics unless otherwise speci ed t a = 25 c, v in = v outnom + 1v, v in = v en , i load = 0.1ma, using test circuit figure 1 spectral noise density and noise voltage ripple rejection vs. frequency termal cycling under short circuit condition on/off transient response load transient response ground current vs. load current 050 66 64 62 60 58 56 54 52 50 100 150 200 load current (ma) ground current ( a) -40c +25c +85c 250 300 350 400
fan2591 6 rev. 1.0.4 12/12/02 ambient temperature ( c) load current (ma) ? vdet (%) dropout voltage (v) threshold voltage vs. temperature output voltage vs. temperature dropout voltage vs. load current rst timeout period v det to rst delay +0.8 +0.4 0 -0.4 -0.8 -1.2 ? vout (%) +0.6 +0.3 0 -0.3 -0.6 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 -40c 25c +85c -40 -20 0 20 40 60 80 ambient temperature ( c) -30 -50 -10 10 30 50 70 90 100 150 200 250 300 350 v det v det rst rst
fan2591 rev. 1.0.4 12/12/02 7 application information detailed description the fan2591 is a combination of a ?ed voltage output, low dropout cmos voltage regulator and a voltage detector with factory programmable v th , for low battery indication or microprocessor reset control. features low supply current, which does not increase with the load current, remains at the low level with the highest load, providing continuous 350ma load current. v out remains stable and within regulation also in very low load current, at the level of 100?, which is crucial in rtc and cmos ram battery back-up application. output and input capacitors a 22? (min.) tantalum capacitor with esr in the range 0.8 ? to 5 ? from v out to ground is required. 10? is acceptable for ambient temperatures above 0?. capaci- tances less than 10? are not recommended because they require careful selection of esr to ensure stability. a min 10? capacitor should also be connected from v in to gnd. when operating from sources other than batteries, supply noise rejection and transient response can be improved by increasing the value of the input and output capacitors and utilizing passive ?tering techniques. bypass input capacitor (optional, xed output voltage only) a 470pf or more capacitor connected from the cnoise input to ground reduces noise present on the internal reference, which in turn signi?antly reduces output noise. this input may be left unconnected. larger capacitor values may be used, depending on the sensitivity to output noise in the application, but this will result in a longer time period to reach the steady state. adjustable output voltage the fan2591adj version includes an fb input which allows the user to select an output voltage in the range of 1.3v to 6.2v, determined by r 1 and r 2 (figure 2) according to the relation: for best results we recommend: thermal shutdown integrated thermal protection circuitry shuts the regulator off when die temperature exceeds 150?. the regulator remains off until the die temperature drops to approximately 130?. voltage detector the threshold voltage v th for voltage detector is preset by the factory within the range 1.5v to 4.8v, for any speci? user request. rst output available for user request can be in active high or active low, or open drain version. the rst output is guaranteed to remain asserted for a minimum of 150ms after v det has risen above the designated preset threshold. also, v in and v det can be connected together. microprocessor reset the rst pin is asserted whenever vdet falls below the preset threshold voltage. the reset pin remains asserted for a typical time period of 200ms after v in has risen above the preset threshold voltage (?. 2). the reset function ensures the microprocessor is properly reset and powers up into a known condition after a power failure. rst will remain valid with vdet as low as 1.4v. vdet transients the fan2591 are relatively immune to negative-going v det glitches below the preset threshold. typically, a negative- going transient 125mv below the detection threshold with a duration of 35? or less will not cause an unwanted reset. figure 3. timing diagram v out v fb 1 r 1 r 2 ------ + ?? ?? = r 1 r 2 ? r 1 r 2 + ------------------- 250k ? v det rst active l active h v th t r t r
fan2591 8 rev. 1.0.4 12/12/02 package dimensions 8-pin msop 0.118 - 0.004 [3 0.1] 85 14 0.193 0.004 [4.9 0.1] 0.118 0.004 [3 0.1] (0.189) [4.8] (0.040) [1.02] symm c land pattern recommendation 0.030 - 0.037 [0.78 - 0.94] 0.021 0.005 [0.53 0.12] 0.007 0.002 [0.18 0.05] 0.002 - 0.006 [0.06 - 0.15] 0.012 0.002 [0.3 0.05] (0.033) [0.84] 0.0375 [0.953] pin 1 ident typ typ typ (0.016) [0.41] typ 0.005 [0.13] typ typ gage plane r 0.005 [0.13] typ typ r (0.0256) [0.65] typ 0 6 typ seating plane (0.0256) [0.65] a b c 0.002 [0.05] 0.002 [0.05] ms a c s b (0.010) [0.23]
fan2591 rev. 1.0.4 12/12/02 9 8-pin mlp 3x3 3.0 1.42 1.99 3.30 (0.65) 0.65 typ 0.47 typ 2.37 3.0 top view recommended land pattern side view bottom view 2x 2x 1.0 max 0.15 0.15 (0.20) seating plane 0.10 0.08 0.65 1.95 notes: a. conforms to jedec registration mo-229, variation vccd 3, dated 11/2001 b. dimensions are in millimeters. c. dimensions and tolerances per asme y14.5m, 1994 0.05 0.00 0.45 0.20 1.30 max 0.25~0.35 0.10 m m 0.05 2.25 max 1 1 4 4 58 5 8 c c c c c ab c c a b
fan2591 life support policy fairchild s products are not authorized for use as critical components in life support devices or systems without the express written approval of the president of fairchild semiconductor corporation. as used herein: 1. life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. a critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 12/12/02 0.0m 004 stock#ds30002591 ? 2002 fairchild semiconductor corporation ordering information for (-40 c to +85 c) temperature range part number nominal output voltage (v) nominal threshold voltage (v) rst con guration package package marking fan2591mu33tlx 3.3 3.08 active low msop-8 591ctl fan2591mu30rlx 3 2.63 active low msop-8 591erl fan2591mp33tlx 3.3 3.08 active low mlp3x3-8 591ctl fan2591mp30rlx 3 2.63 active low mlp3x3-8 591erl FAN2591MUADJROX adj 2.63 open drain active low msop-8 591rrl fan2591mpadjrox adj 2.63 open drain active low mlp3x3-8 591rrl disclaimer fairchild semiconductor reserves the right to make changes without further notice to any products herein to improve reliability, function or design. fairchild does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights, nor the rights of others.
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