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19-1263; Rev 0; 7/97 350mA, 16.5V Input, Low-Dropout Linear Regulators _______________General Description The MAX1658/MAX1659 linear regulators maximize battery life by combining ultra-low supply currents and low dropout voltages. They feature Dual ModeTM operation, which presets the output to 3.3V (MAX1658) or 5V (MAX1659), or permits it to be adjusted between 1.25V and 16V. The regulator supplies up to 350mA, with a typical dropout of 650mV for the MAX1658 and 490mV for the MAX1659. With their P-channel MOSFET pass transistor, these devices maintain a low quiescent current from zero output current to the full 350mA, even in dropout. They support input voltages ranging from 2.7V to 16.5V. The MAX1658/MAX1659 feature a 1A shutdown mode, reverse battery protection, short-circuit protection, and thermal shutdown. They are available in a special highpower (1.2W), 8-pin SO package designed specifically for compact applications. ____________________________Features o Wide Input Voltage Range: 2.7V to 16.5V o Low, 490mV Dropout at 350mA Output Current (MAX1659) o 30A Supply Current o 1A Max Shutdown Current o High-Power (1.2W) 8-Pin SO Package o Dual Mode Operation Output: Fixed 3.3V (MAX1658) Fixed 5.0V (MAX1659) or Adjustable (1.25V to 16V) o Thermal Overload Protection o Current-Limit Protection o Reverse Battery Protection MAX1658/MAX1659 ________________________Applications Digital Cordless Phones PCS Phones Cellular Phones PCMCIA Cards Modems Hand-Held Instruments Palmtop Computers Electronic Planners ______________Ordering Information PART MAX1658C/D MAX1658ESA MAX1659C/D MAX1659ESA TEMP. RANGE 0C to +70C -40C to +85C 0C to +70C -40C to +85C PIN-PACKAGE Dice* 8 SO Dice* 8 SO *Dice are tested at TA = +25C, DC parameters only. __________Typical Operating Circuit OUTPUT 3.3V OR 5V, OR ADJ. (DOWN TO 1.25V); UP TO 350mA IN OUT __________________Pin Configuration INPUT UP TO 16.5V TOP VIEW SET 1 2 3 8 7 GND IN IN OUT MAX1658 MAX1659 ON OFF SHDN GND SET SHDN IN MAX1658 MAX1659 6 5 OUT 4 SO Dual Mode is a trademark of Maxim Integrated Products. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468. 350mA, 16.5V Input, Low-Dropout Linear Regulators MAX1658/MAX1659 ABSOLUTE MAXIMUM RATINGS IN to GND ................................................................-17V to +17V Continuous Output Current ...............................................500mA Output Short-Circuit Duration ............................................Infinite SET, SHDN to GND .................................................-17V to +17V OUT to GND ................................................-0.3V to (VIN + 0.3V) Continuous Power Dissipation (Note 1) SO (derate 14.5mW/C above +70C) .............................1.2W Note 1: See Operating Region and Power Dissipation section. Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Operating Temperature Range MAX1658ESA/MAX1659ESA ............................-40C to +85C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +160C Lead Temperature Range (soldering, 10sec)..................+300C ELECTRICAL CHARACTERISTICS (VIN = 5V (MAX1658), VIN = 6V (MAX1659); COUT = 10F; SHDN = IN; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER Input Voltage Range SYMBOL VIN SET = OUT MAX1658, 5V VIN 16.5V SET = GND, 0mA < ILOAD < 350mA MAX1659, 6V VIN 16.5V (Note 3) IOUT(MAX) ILIM IQ IOUT = 1mA Dropout Voltage (Note 4) VDO IOUT = 350mA MAX1658 MAX1659 CONDITIONS MIN 2.7 3.20 4.85 1.25 350 900 30 2 650 490 0.03 0.05 0.003 0 10Hz to 100kHz 2.7V VIN 16.5V 2.7V VIN 16.5V SHDN = GND or SHDN = IN SHDN 0.4V VOUT = 5.0V 2.0 0.1 0.1 120 1 2.5 0.4 1500 875 %/V %/mA %VOUT mVp-p V V A A s mV 60 3.30 5.00 TYP MAX 16.5 3.40 V 5.15 16 V mA mA A UNITS V Output Voltage VOUT Regulated Output Voltage Range Maximum Output Current Current Limit Supply Current Line Regulation Load Regulation Startup Overshoot Output Noise SHUTDOWN Logic-Low Input Logic-High Input Threshold Shutdown Input Bias Current Shutdown Supply Current Shutdown Exit Time VLNR VLDR VOSH en VINLSHDN VINHSHDN ISHDN IQSHDN tSTART MAX1658, VIN = 5V to 16.5V MAX1659, VIN = 6V to 16.5V IOUT = 0mA to 350mA 2 _______________________________________________________________________________________ 350mA, 16.5V Input, Low-Dropout Linear Regulators ELECTRICAL CHARACTERISTICS (continued) (VIN = 5V (MAX1658), VIN = 6V (MAX1659); COUT = 10F; SHDN = IN; TA = TMIN to TMAX; unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER SET INPUT SET Reference Voltage SET Input Leakage Current THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis TSD TSD 165 10 C C VSET ISET IOUT = 10A (Note 3) TA = +25C (Note 3) TA = +85C (Note 3) 1.174 1.210 0.01 0.1 1.246 0.025 V A SYMBOL CONDITIONS MIN TYP MAX UNITS MAX1658/MAX1659 Note 2: Specifications to -40C are guaranteed by design, not production tested. Note 3: Adjustable configuration only. VIN = 16.5V. Note 4: The dropout voltage is defined as (VIN - VOUT) when VOUT is 100mV below the value of VOUT for VIN = VOUT + 2V. __________________________________________Typical Operating Characteristics (VIN = 5V (MAX1658), VIN = 6V (MAX1659); SHDN = IN; SET = GND; CIN = 0.1F; COUT = 10F tantalum; TA = +25C; unless otherwise noted.) MAX1658 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX1658 TOC01 MAX1659 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY -16 -24 PSSR (dB) -32 -40 -48 -56 MAX1658 TOC03 -10 -20 -30 PSRR (dB) -40 -50 -60 -70 -80 -90 10 100 1000 FREQUENCY (Hz) 10k VIN = 5.2V TO 5.4V VOUT = 3.3V -8 -64 -72 100k 10 100 1000 VIN = 6.15V TO 6.4V VOUT = 5V 10k 100k FREQUENCY (Hz) _______________________________________________________________________________________ 3 350mA, 16.5V Input, Low-Dropout Linear Regulators MAX1658/MAX1659 ____________________________Typical Operating Characteristics (continued) (VIN = 5V (MAX1658), VIN = 6V (MAX1659); SHDN = IN; SET = GND; CIN = 0.1F; COUT = 10F tantalum; TA = +25C; unless otherwise noted.) NORMALIZED OUTPUT VOLTAGE vs. LOAD CURRENT MAX1658/59 TOC05 MAX1658 SUPPLY CURRENT vs. INPUT VOLTAGE VOUT = 3.3V SUPPLY CURRENT (A) 60 IL = 100mA 40 MAX1658/59 TOC06 QUIESCENT CURRENT vs. LOAD CURRENT MAX1658/59 TOC09 1.000 OUTPUT VOLTAGE VNOMINAL/VOUT (V) 80 140 120 QUIESCENT CURRENT (A) 100 80 60 40 20 0.998 5V OUTPUT 0.996 0.994 3.3V OUTPUT 0.992 20 IL = 0mA 0.990 0 100 200 300 400 OUTPUT CURRENT (mA) 0 0 3 6 9 12 15 18 INPUT VOLTAGE (V) 0 0 50 100 150 200 250 300 350 400 LOAD CURRENT (mA) DROPOUT VOLTAGE vs. OUTPUT VOLTAGE MAX1658/59 TOC07 DROPOUT VOLTAGE vs. LOAD CURRENT 700 DROPOUT VOLTAGE (mV) 600 VOUT = 3.3V 500 400 300 200 100 0 0 100 200 300 400 VOUT = 5.0V B MAX1658/59 TOC08 MAX1658 LINE-TRANSIENT RESPONSE MAX1658/59TOC11 2000 800 DROPOUT VOLTAGE (mV) 1500 A 1000 500 IL = 350mA 0 0 3 6 9 12 15 OUTPUT VOLTAGE (V) VOUT = 3.3V 100s/div A: INPUT VOLTAGE (1V/div), VIN = 6V (HIGH), VIN = 5V (LOW) B: OUTPUT VOLTAGE (100mV/div) LOAD CURRENT (mA) MAX1659 LINE-TRANSIENT RESPONSE MAX1658/59TOC10 MAX1658 LOAD-TRANSIENT RESPONSE MAX1658/59TOC13 MAX1659 LOAD-TRANSIENT RESPONSE MAX1658/59TOC12 A A A B B VOUT = 5.0V 100s/div A: INPUT VOLTAGE (1V/div), VIN = 7V (HIGH), VIN = 6V (LOW) B: OUTPUT VOLTAGE (100mV/div) B VOUT = 3.3V 200s/div A: OUTPUT VOLTAGE (100mV/div) B: IOUT = 300mA (HIGH), IOUT = 40mA (LOW) VOUT = 5V 200s/div A: OUTPUT VOLTAGE (100mV/div) B: IOUT = 300mA (HIGH), IOUT = 40mA (LOW) 4 _______________________________________________________________________________________ 350mA, 16.5V Input, Low-Dropout Linear Regulators ____________________________Typical Operating Characteristics (continued) (VIN = 5V (MAX1658), VIN = 6V (MAX1659); SHDN = IN; SET = GND; CIN = 0.1F; COUT = 10F tantalum; TA = +25C; unless otherwise noted.) MAX1658 OVERSHOOT AND TIME EXITING SHUTDOWN MAX1658/59TOC14 MAX1658/MAX1659 MAX1659 OVERSHOOT AND TIME EXITING SHUTDOWN MAX1658/59TOC15 3.3V 5V A 0V A 0V B B 100s/div A: OUTPUT VOLTAGE (1V/div) B: SHDN PIN VOLTAGE (2V/div) 100s/div A: OUTPUT VOLTAGE (2V/div) B: SHDN PIN VOLTAGE (2V/div) OUTPUT NOISE 104 OUTPUT NOISE DENSITY (nVRMS/Hz) OUTPUT NOISE DENSITY vs. FREQUENCY MAX1658 TOC02 103 102 VOUT = 5V IOUT = 165mA 10 10 FREQUENCY (Hz) 50k 10ms/div 10Hz TO 100kHz NOISE, VOUT = 5V (1mV/div), IOUT = 165mA ______________________________________________________________Pin Description PIN 1 2 3, 6, 7 NAME SET SHDN IN FUNCTION Output Voltage Input. Connecting SET to ground selects the factory-preset 3.3V (MAX1658) or 5V (MAX1659) output voltage. For an adjustable output voltage, connect SET to a resistive voltage divider from OUT to GND. Shutdown Input. When SHDN is low, the device turns off and typically draws 0.1A of supply current. Unregulated Input Supply Voltage, 2.7V to 16.5V input range. The IN pins also serve as heatsinks. Connect to a copper plane to achieve maximum thermal dissipation. Regulated Output Voltage. Fixed or adjustable from 1.25V to 16V. Sources up to 350mA. For stable operation, bypass with a 10F, low-ESR (<0.2) capacitor from OUT to GND. For improved load-transient response, use a larger low-ESR capacitor. Ground _______________________________________________________________________________________ 5 4, 5 8 OUT GND 350mA, 16.5V Input, Low-Dropout Linear Regulators MAX1658/MAX1659 IN SHDN P 1.21V REFERENCE THERMAL SENSOR ERROR AMPLIFIER MOSFET DRIVER WITH CURRENT LIMIT P OUT R1 SET R2 DUAL-MODE COMPARATOR MAX1658 MAX1659 65mV GND Figure 1. Functional Diagram _______________Detailed Description The MAX1658/MAX1659 are micropower, low-dropout linear regulators featuring Dual ModeTM operation, which allows them to deliver an adjustable (1.25V to 16.5V) or preset (3.3V for the MAX1658, 5V for MAX1659) output. They supply up to 350mA while requiring only 120A of supply current (typically 30A with no load). The devices include thermal shutdown circuitry, output current limiting, a P-channel pass transistor, a Dual Mode comparator, and a feedback voltage divider. Figure 1 shows the functional diagram. The 1.21V reference is connected to the amplifier's inverting input. The error amplifier compares this reference with the selected feedback voltage and amplifies 6 the difference. The error signal applies the drive to the P-channel pass transistor. If the feedback voltage is lower than the reference voltage, the transistor's gate is pulled lower, increasing output current. The output voltage is fed back through an internal resistor network or an external user-selected network. The Dual Mode comparator examines the voltage at the SET pin and selects either the internal or external feedback path. If SET is below 65mV, internal feedback sets the MAX1658's output voltage to 3.3V and the MAX1659's to 5V. Otherwise, external feedback is used for an adjustable output between 1.25V and 16.5V. Additional features include internal current limiting, reverse battery protection, thermal-overload protection, and a 1A shutdown mode. _______________________________________________________________________________________ 350mA, 16.5V Input, Low-Dropout Linear Regulators P-Channel Pass Transistor The MAX1658/MAX1659 feature an internal P-channel MOSFET pass transistor. Using a MOSFET provides several advantages over similar PNP designs, including lower dropout voltage and extended battery life. Unlike bipolar transistors, MOSFETs reduce quiescent current, because they require no base current, particularly at heavy loads and in dropout. As a result, the MAX1658/MAX1659 operate at a low quiescent current even in dropout. ogy of a typical circuit operating in adjustable mode. The output voltage is set by the following equation: R1 VOUT = VSET 1 + R2 where VSET = 1.21V. Solving for R1 yields: V R1 = R2 OUT - 1 VSET The input leakage current of the SET input is less than 25nA. This allows the use of large resistors in the feedback network to minimize output current loss without compromising accuracy. R2 can be as high as 500k in most applications. MAX1658/MAX1659 Output Voltage Selection Dual Mode operation allows the MAX1658/MAX1659 to operate at either a preset or a user-adjustable output voltage. The device compares the SET pin voltage with an internal 65mV reference. If the voltage is lower than 65mV (typically achieved by grounding SET), the device switches to an internal resistor-divider feedback network that sets the output voltage. The MAX1658's preset output voltage is 3.3V and the MAX1659's is 5V (Figure 2). If the SET pin is not below 65mV, the device switches to external feedback and SET becomes a feedback input. The feedback network can be configured to produce an output between 16V and the voltage reference (nominally 1.21V). Under regulation, the feedback mechanism adjusts the error signal such that the voltage at the SET pin equals the reference voltage. Therefore, to achieve the minimum output, connect SET directly to OUT. For other voltages, a resistive voltagedivider network is necessary. Figure 3 shows the topol- Shutdown A logic low on the SHDN pin places the MAX1658/ MAX1659 in shutdown. This mode deactivates all functions, including the pass transistor. The device consumes less than 1A of supply current in shutdown, and its output becomes high impedance. The MAX1658/MAX1659 exit shutdown in 100s. Output Current Limit The MAX1658/MAX1659 include current-limiting circuitry that monitors and controls the pass transistor and limits output current to around 900mA. The output can be shorted to ground indefinitely without damaging the device. ON OFF 2 SHDN OUT 4, 5 OUTPUT VOLTAGE 3.3V/350mA (5V/350mA) INPUT VOLTAGE 3, 6, 7 IN MAX1658 MAX1659 OUT 4, 5 OUTPUT VOLTAGE INPUT VOLTAGE 3, 6, 7 MAX1658 (MAX1659) IN 10F 0.1F GND 8 SET 1 2 SHDN SET 1 R1 COUT 10F R2 GND 8 0.1F VOUT = VSET 1 + R1 R2 VSET = 1.21V ( ) Figure 2. Preset Output Configuration Figure 3. Adjustable Output Configuration Using External Feedback Resistors 7 _______________________________________________________________________________________ 350mA, 16.5V Input, Low-Dropout Linear Regulators MAX1658/MAX1659 Thermal-Overload Protection Thermal-overload protection limits total power dissipation in the MAX1658/MAX1659. When the junction temperature exceeds TJ = +165C, the pass transistor deactivates, allowing the IC to cool. Once it has cooled by 10C, the control logic will enable operation. Under thermal overload, the output of the device will pulse as the die heats up and then cools to operational levels. Prolonged operation under these conditions is not recommended. 1600 1400 POWER DISSIPATION (mW) Tj = +125C 1200 1000 800 600 400 0.1 0.65 Tj = +85C Operating Region and Power Dissipation Maximum power dissipation of the MAX1658/MAX1659 depends on the thermal resistance of the package and circuit board, the temperature difference between the die and ambient air, and the rate of air flow. The power dissipation by the device is P = IOUT (VIN - VOUT). The maximum power dissipation is: TJ - TA PMAX = JB + BA SINGLE-SIDED 1oz. COPPER TA = +25C, STILL AIR 1 6.5 COPPER GROUND PAD AREA 10 (in2) 65 (cm2) ( ( ) ) Figure 4. Typical Maximum Power Dissipation vs. Ground Pad Area where (TJ - TA) is the temperature difference between MAX1658/MAX1659 die junction and the surrounding air, JB is the thermal resistance of the package, and BA is the thermal resistance through the printed circuit board, copper traces, and other materials to the surrounding air. The 8-pin SO package for the MAX1658/MAX1659 features a special lead frame with a lower thermal resistance and higher allowable power dissipation than a standard SO-8. The thermal resistance of this package is JB = 69C/W, compared with JB = 170C/W for an SO-8. The IN pins of the MAX1658/MAX1659 package perform the dual function of providing an electrical connection to IN and channeling heat away. Connect all IN pins to the input voltage using a large pad or power plane on the surface. Where this is impossible, connect to a copper plane on an adjacent layer. The pad should meet the dimensions specified in Figure 4. Figure 4 assumes the IC is soldered directly to the pad, has a +125C maximum junction temperature and a +25C ambient air temperature, and has no other heat sources. Use larger pad sizes for lower junction temperatures, higher ambient temperatures, or conditions where the IC is not soldered directly to a heat-sinking IN pad. The MAX1658/MAX1659 can regulate currents up to 350mA and operate with input voltages up to 16.5V, but not simultaneously. High output currents can only be sustained when input-output differential voltage is low, as shown in the following equation. Maximum power dissipation depends on packaging, board layout, temperature, and air flow. The maximum output current is: IOUT(MAX) = ( PMAX x 125C - TA VIN - VOUT x 100C ( ) ) where PMAX is derived from the TJ = 125C curve of Figure 4. Reverse Battery Protection The MAX1658/MAX1659 feature reverse battery protection. Under normal operation, a P-channel MOSFET connects the substrate of the device to IN. When the input voltage falls below ground (implying reverse battery conditions), the P-channel switch turns off and disconnects the substrate from IN, disabling the device. The maximum reverse battery voltage allowed is -17V. SHDN also withstands reverse battery conditions and can be connected directly to IN with no loss of protection. Polarized input bypass capacitors will be damaged under reverse battery conditions. To ensure circuit reliability, use a non-polarized capacitor at the input. The MAX1658/MAX1659 do not provide reverse current protection. If VOUT is greater than VIN by more than 300mV, reverse current will flow. Reverse current protection can be added by connecting a Schottky diode in series with IN. 8 _______________________________________________________________________________________ 350mA, 16.5V Input, Low-Dropout Linear Regulators __________Applications Information To maintain stability, connect a 10F capacitor with less than 200m equivalent series resistance (ESR) from OUT to GND. Larger output capacitors improve load-transient response. Currents lower than 350mA make the use of smaller output capacitors possible. Table 1 shows the maximum output current typically achieved using various output capacitors. Output voltages higher than 3.3V require less output capacitance to remain stable. Input Bypass Capacitor The use of a 0.1F to 10F input bypass capacitor is recommended. Larger capacitors provide better supply-noise rejection and line-transient response, as well as improved performance when the supply has a high AC impedance. Polarized input bypass capacitors will be damaged under reverse battery conditions. If reverse input voltages are expected, use a non-polarized capacitor at the input. MAX1658/MAX1659 Output Capacitor Selection and Stability Noise and PSRR The MAX1658/MAX1659 exhibit 2.5mVp-p of noise during normal operation. This noise level is negligible in most applications. The MAX1658/MAX1659 are designed to maintain excellent power-supply rejection (55dB) at 50Hz/60Hz (or 50dB at 120Hz). These regulators are ideal for wallcube applications that may contain significant ripple. Larger input and output capacitors will further improve the circuit's AC response. See the Power-Supply Rejection Ratio vs. Frequency graphs in the Typical Operating Characteristics. Table 1. Typical Load Current Capabilities OUTPUT CAPACITOR 2.2F tantalum 4.7F tantalum 10F tantalum LOAD CURRENT RANGE 0mA to 120mA 0mA to 250mA 0mA to 350mA ___________________Chip Information TRANSISTOR COUNT: 207 _______________________________________________________________________________________ 9 350mA, 16.5V Input, Low-Dropout Linear Regulators MAX1658/MAX1659 ________________________________________________________Package Information SOICN.EPS 10 ______________________________________________________________________________________ 350mA, 16.5V Input, Low-Dropout Linear Regulators NOTES MAX1658/MAX1659 11 ______________________________________________________________________________________ 350mA, 16.5V Input, Low-Dropout Linear Regulators MAX1658/MAX1659 NOTES Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. |
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