19-1556; Rev 0; 10/99 150mA, Low-Dropout Linear Regulator with Power-OK Output Features ♦ Power-OK Output ♦ Small Output Capacitor (1µF ceramic) ♦ Preset Output Voltages (±1% accuracy) ♦ Guaranteed 150mA Output Current ♦ 85µA No-Load Supply Current ♦ Low 110mV Dropout at 100mA Load (165mV at 150mA load) ♦ Thermal-Overload and Short-Circuit Protection ♦ Reverse-Battery Protection ♦ 60dB PSRR at 100Hz ♦ 1µA max Shutdown Current The MAX8875 is optimized for use with a 1µF ceramic output capacitor. For a pin-compatible, functionally equivalent device for use with a higher ESR output capacitor, see the MAX8885 data sheet. Applications Ordering Information PCS Telephones Hand-Held Instruments PART TEMP. RANGE PIN-PACKAGE Cellular Telephones Palmtop Computers MAX8875EUK25-T -40°C to +85°C 5 SOT23-5 Cordless Telephones Electronic Planners PCMCIA Cards Modems MAX8875EUK27-T MAX8875EUK30-T MAX8875EUK33-T -40°C to +85°C -40°C to +85°C -40°C to +85°C 5 SOT23-5 5 SOT23-5 5 SOT23-5 MAX8875EUK50-T -40°C to +85°C 5 SOT23-5 Output Voltage Selector Guide PART MAX8875EUK25 VOUT (V) 2.5 TOP MARK ADKZ MAX8875EUK27 MAX8875EUK30 MAX8875EUK33 2.7 3.0 3.3 ADLA ADLB ADLC Note: See Output Voltage Selector Guide for more information. MAX8875EUK50 5.0 ADLD Note: Other output voltages between 2.5V and 5.0V are available in 100mV increments—contact the factory for information. Minimum order quantity is 25,000 units. Typical Operating Circuit Pin Configuration INPUT +2.5V TO +6.5V TOP VIEW IN IN 1 GND 2 5 OUT COUT 1µF CIN 1µF OUT MAX8875 MAX8875 100k ON OFF SHDN 3 OUTPUT PRESET 2.5V TO 5.0V 150mA 4 POK POK SHDN TO µC GND SOT23-5 ________________________________________________________________ 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 1-800-835-8769. MAX8875 General Description The MAX8875 low-dropout linear regulator operates from a +2.5V to +6.5V input range and delivers up to 150mA. A P-channel MOSFET pass transistor allows its 85µA supply current to remain independent of the load, making this device ideal for battery-operated portable equipment such as PCS phones, cellular phones, cordless phones, and modems. The MAX8875 features a power-OK output that indicates when the output is out of regulation. The device is available in several preset output voltage versions: 5.0V, 3.3V, 3.0V, 2.7V, or 2.5V. Other features include 1µA (max) shutdown current, short-circuit protection, thermal shutdown protection, and reverse-battery protection. The device comes in a miniature 5-pin SOT23 package. MAX8875 150mA, Low-Dropout Linear Regulator with Power-OK Output ABSOLUTE MAXIMUM RATINGS IN, SHDN, POK to GND...............................................-7V to +7V SHDN to IN ...............................................................-7V to +0.3V OUT to GND ................................................-0.3V to (VIN + 0.3V) Output Short-Circuit Duration ........................................Indefinite Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C)..........571mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C θJA ...............................................................................+140°C/W Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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. ELECTRICAL CHARACTERISTICS (VIN = VOUT(NOMINAL) + 1V, SHDN = IN, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Input Voltage SYMBOL CONDITIONS Maximum Output Current IOUT Current Limit ILIM Ground Pin Current Dropout Voltage (Note 2) IQ VIN - VOUT MAX UNITS V 2.5 6.5 1.0 IOUT = 100µA -2 2 IOUT = 100µA to 120mA -3 2 TA = +25°C, IOUT = 100µA TA = -40°C to +85°C TYP -1.0 VIN Output Voltage Accuracy MIN 150 160 % mA 390 IOUT = 100µA 85 IOUT = 150mA 100 IOUT = 100µA 0.1 IOUT = 50mA 50 IOUT = 100mA 110 mA 180 220 µA mV 165 IOUT = 150mA Line Regulation ∆VLNR VIN = (VOUT + 0.1V) to 6.5V, IOUT = 1mA Load Regulation ∆VLDR IOUT = 100µA to 120mA, COUT = 1µF 0.01 %/mA COUT = 10µF, f = 10Hz to 100kHz 170 µVRMS f = 100Hz 60 dB Output Voltage Noise Output Voltage AC PowerSupply Rejection Ratio PSRR -0.15 0 0.15 %/V SHUTDOWN Shutdown Supply Current SHDN Input Threshold SHDN Input Bias Current IOFF VIH VIL ISHDN SHDN = GND TA = +25°C 0.005 TA = +85°C 0.02 2.0 VIN = 2.5V to 5.5V SHDN = IN or GND 1 0.4 TA = +25°C 0 TA = +85°C 0.05 100 µA V nA POWER-OK OUTPUT Power-OK Voltage Threshold VPOK (1 - VOUT / VOUT(NOMINAL) 100, IOUT = 0, VOUT falling In dropout, VOUT falling Hysteresis, IOUT = 0 2 -3 -5 -5.3 1 _______________________________________________________________________________________ -8 % 150mA, Low-Dropout Linear Regulator with Power-OK Output (VIN = VOUT(NOMINAL) + 1V, SHDN = IN, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL POK Output Voltage Low VOL CONDITIONS MIN TYP ISINK = 1mA 0 ≤ VPOK ≤ 6.5V, VOUT in regulation POK Output Leakage Current MAX UNITS 0.4 V 1 µA THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis TSHDN 170 °C ∆TSHDN 20 °C Note 1: Limits are 100% production tested at TA = +25°C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control (SQC) methods. Note 2: Dropout voltage is defined as VIN - VOUT, when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V. Typical Operating Characteristics (MAX8875EUK30, VIN = +3.6V, CIN = COUT = 1µF, SHDN = IN, TA = +25°C, unless otherwise noted.) GROUND PIN CURRENT vs. OUTPUT LOAD IOUT = 0 60 40 VIN = 5.0V 105 100 VIN = 3.5V 95 VIN = VOUT(NOMINAL) + 0.5V 115 90 20 2 3 4 5 OUTPUT VOLTAGE vs. OUTPUT LOAD 3.5 3.0 OUTPUT VOLTAGE (V) VIN = 5.0V IOUT = 150mA 110 VIN = 3.6V IOUT = 150mA VIN = 3.6V OR 5.0V IOUT = 0 80 IOUT = 0 2.5 2.0 IOUT = 150mA 1.5 1.0 10 35 TEMPERATURE (°C) 60 3.05 3.00 VIN = 3.6V 2.95 VIN = 5.0V 2.90 0 60 -15 3.10 0.5 70 -40 15 30 45 60 75 90 105 120 135 150 OUTPUT LOAD (mA) OUTPUT VOLTAGE vs. INPUT VOLTAGE 130 90 0 OUTPUT LOAD (mA) GROUND PIN CURRENT vs. TEMPERATURE 100 VOUT = 3.0V MAX8875EUK30 95 15 30 45 60 75 90 105 120 135 150 INPUT VOLTAGE (V) 120 100 85 0 6 OUTPUT VOLTAGE (V) 1 MAX8875toc05 0 105 90 85 0 VOUT = 5.0V MAX8875EUK50 110 85 MAX8875toc03 110 120 MAX8875toc06 80 115 MAX8875toc02 100 GROUND PIN CURRENT (µA) GROUND PIN CURRENT (µA) IOUT = 150mA GROUND PIN CURRENT (µA) MAX8875toc01 120 GROUND PIN CURRENT vs. OUTPUT LOAD GROUND PIN CURRENT (µA) GROUND PIN CURRENT vs. INPUT VOLTAGE 0 1 2 3 4 INPUT VOLTAGE (V) 5 6 0 15 30 45 60 75 90 105 120 135 150 OUTPUT LOAD (mA) _______________________________________________________________________________________ 3 MAX8875 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (MAX8875EUK30, VIN = +3.6V, CIN = COUT = 1µF, SHDN = IN, TA = +25°C, unless otherwise noted.) DROPOUT VOLTAGE vs. OUTPUT LOAD 3.00 VIN = 3.6V IOUT = 150mA 2.95 200 50 COUT = 10µF 150 TA = +85°C TA = +25°C 100 -15 10 35 60 TA = -40°C 0 0 85 0 0.01 30 45 60 75 90 105 120 135 150 f = 10Hz TO 100kHz COUT = 10µF IOUT = 50mA 10 100 1000 100 COUT ESR (Ω) 10 1 VOUT 500µV/div COUT = 10µF 1 COUT = 1µF 0.1 STABLE REGION 0.1 0.01 10 1 1 10ms/div 100 MAX8875toc14 MAX8875toc13 3.01V 3.00V 2.99V 3.02V ILOAD ILOAD 50mA 0 2.98V 10µs/div IOUT = 50mA 3.00V 2.99V 50mA 3.00V 90 3.01V VOUT VOUT 4V 60 120 150 LOAD-TRANSIENT RESPONSE NEAR DROPOUT LOAD-TRANSIENT RESPONSE LINE-TRANSIENT RESPONSE 5V 30 LOAD CURRENT (mA) FREQUENCY (kHz) MAX8875toc15 0.1 VIN 1 REGION OF STABLE COUT ESR vs. LOAD CURRENT 0.01 4 0.1 FREQUENCY (kHz) OUTPUT NOISE MAX8875toc10 OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) OUTPUT NOISE SPECTRAL DENSITY vs. FREQUENCY COUT = 10µF IOUT = 50mA 15 OUTPUT LOAD (mA) TEMPERATURE (°C) 10 10 MAX8875toc12 -40 30 COUT = 1µF MAX8875toc11 2.90 40 20 50 VIN = 5.0V IOUT = 150mA 60 PSRR (dB) VIN = 3.6V OR 5.0V IOUT = 0 3.05 70 MAX8875toc08 MAX8875toc07 250 DROPOUT VOLTAGE (mV) OUTPUT VOLTAGE (V) 3.10 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX8875toc09 OUTPUT VOLTAGE vs. TEMPERATURE VOUT MAX8875 150mA, Low-Dropout Linear Regulator with Power-OK Output 0 10µs/div VIN = VOUT + 0.5V, IOUT = 0 TO 50mA 10µs/div VIN = VOUT + 0.1V, IOUT = 0 TO 50mA _______________________________________________________________________________________ 150mA, Low-Dropout Linear Regulator with Power-OK Output SHUTDOWN DELAY 3V MAX8875toc17 MAX8875toc16 POK OUTPUT VOUT 1V/div 0 VPOK 2V/div 0 0 2V VOUT 2V/div 4V VSHDN 1V/div 0 VIN 1V/div 3V 2V 100µs/div 200µs/div MAX8875EUK30, ROUT = 60Ω RPOK = 100kΩ POK AND SHUTDOWN RESPONSE MAX8875toc18 VIN 2.5V/div MAX8875toc19 POK STARTUP RESPONSE 5.0V 2V VSHDN 2V/div 0 0 VOUT 2.5V/div 2.5V 2V 0 0 5.0V 4V VOUT 2V/div VPOK 2V/div VPOK 2.5V/div 0 0 RLOAD = 60Ω 10µs/div 10ms/div RPOK = 100kΩ RPOK = 100kΩ Pin Description PIN NAME FUNCTION 1 IN 2 GND Ground. This pin also functions as a heatsink. Solder to a large pad or the circuit-board ground plane to maximize power dissipation. 3 SHDN Active-Low Shutdown Input. A logic low reduces the supply current to below 1µA. Connect to IN for normal operation. 4 POK Power-OK Output. Active-low, open-drain output indicates an out-of-regulation condition. Connect a 100k pull-up resistor to OUT for logic levels. If not used, leave this pin unconnected. 5 OUT Regulator Output. Fixed 5.0V, 3.3V, 3.0V, 2.7V, or 2.5V output. Sources up to 150mA. Bypass with 1µF (<0.2Ω typical ESR) ceramic capacitor to GND. Regulator Input. Supply voltage can range from 2.5V to 6.5V. Bypass with 1µF to GND (see the Capacitor Selection and Regulator Stability section). _______________________________________________________________________________________ 5 MAX8875 Typical Operating Characteristics (continued) (MAX8875EUK30, VIN = +3.6V, CIN = COUT = 1µF, SHDN = IN, TA = +25°C, unless otherwise noted.) MAX8875 150mA, Low-Dropout Linear Regulator with Power-OK Output IN SHDN REVERSEBATTERY PROTECTION P MOS DRIVER WITH ILIMIT ERROR AMP SHUTDOWN LOGIC OUT MAX8875 POK THERMAL SENSOR 1.25V REF POK 95% REF GND Figure 1. Functional Diagram _______________Detailed Description The MAX8875 is a low-dropout, low-quiescent-current linear regulator designed primarily for battery-powered applications. The device supplies loads up to 150mA and is available with preset output voltages of 2.5V, 2.7V, 3.0V, 3.3V, or 5.0V. As illustrated in Figure 1, the MAX8875 consists of a 1.25V reference, error amplifier, P-channel pass transistor, power-OK comparator, and internal feedback voltage divider. The 1.25V bandgap reference is connected to the error amplifier’s inverting input. The error amplifier compares this reference with the feedback voltage and amplifies the difference. If the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled lower, which allows more current to pass to the output and increases the output voltage. If the feedback voltage is too high, the pass-transistor gate is pulled up, allowing less current to pass to the output. The output voltage feeds back through an internal resistor voltage divider connected to the OUT pin. Additional blocks include a current limiter, reversebattery protection, thermal sensor, and shutdown logic. Output Voltage The MAX8875 is supplied with factory-set output voltages of 2.5V, 2.7V, 3.0V, 3.3V, or 5.0V. The part number’s two-digit suffix identifies the nominal output voltage. For example, the MAX8875EUK33 has a preset output voltage of 3.3V (see Output Voltage Selector Guide). 6 Internal P-Channel Pass Transistor The MAX8875 features a 1.1Ω (typ) P-channel MOSFET pass transistor. This provides several advantages over similar designs using PNP pass transistors, including longer battery life. The P-channel MOSFET requires no base drive, which reduces quiescent current significantly. PNP-based regulators waste considerable current in dropout when the pass transistor saturates. They also use high base-drive currents under large loads. The MAX8875 does not suffer from these problems and consumes only 100µA of quiescent current whether in dropout, light-load, or heavy-load applications (see Typical Operating Characteristics). Power-OK Output When the output voltage goes out of regulation—as during dropout, current limit, or thermal shutdown—POK goes low. POK is an open-drain N-channel MOSFET. To obtain a logic-level output, connect a pull-up resistor from POK to OUT. To minimize current consumption, make this resistor as large as practical. A 100kΩ resistor works well for most applications. A capacitor to GND may be added to generate a power-on-reset (POR) delay. The POK function is not active during shutdown. POK also provides a power-on-reset function that can operate down to VIN ≤ 1V. See POK Startup Response in the Typical Operating Characteristics. _______________________________________________________________________________________ 150mA, Low-Dropout Linear Regulator with Power-OK Output Thermal-Overload Protection When the junction temperature exceeds TJ = +170°C, the thermal sensor signals the shutdown logic, turning off the pass transistor and allowing the IC to cool. The thermal sensor will turn the pass transistor on again after the IC’s junction temperature cools by 20°C, resulting in a pulsed output during continuous thermal-overload conditions.Thermal-overload protection is designed to protect the MAX8875 in the event of fault conditions. For continuous operation, do not exceed the absolute maximum junction-temperature rating of TJ = +150°C. Operating Region and Power Dissipation The MAX8875’s maximum power dissipation depends on the thermal resistance of the case and circuit board, the temperature difference between the die junction and ambient air, and the rate of air flow. The power dissipation across the device is P = IOUT (VIN - VOUT). The maximum power dissipation is: PMAX = (TJ - TA) / (θJB + θBA) where TJ - TA is the temperature difference between the MAX8875 die junction and the surrounding air, θJB (or θJC) is the thermal resistance of the package, and θBA is the thermal resistance through the printed circuit board, copper traces, and other materials to the surrounding air. The MAX8875’s ground pin (GND) performs the dual function of providing an electrical connection to system ground and channeling heat away. Connect GND to the system ground using a large pad or ground plane. Reverse-Battery Protection The MAX8875 has a unique protection scheme that limits the reverse supply current to 1mA when either VIN or V SHDN falls below ground. The circuitry monitors the polarity of these two pins and disconnects the internal circuitry and parasitic diodes when the battery is reversed. This feature prevents device damage. __________Applications Information Capacitor Selection and Regulator Stability For stable operation over the full temperature range and with load currents up to 150mA, use a 1µF (min) ceramic output capacitor with an ESR <0.2Ω. To reduce noise and improve load-transient response, stability, and power-supply rejection, use large output capacitor values, such as 10µF. Note that some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. With dielectrics such as Z5U and Y5V, it may be necessary to use 2.2µF or more to ensure stability at temperatures below TA = -10°C. With X7R or X5R dielectrics, 1µF should be sufficient at all operating temperatures. Also, for high-ESR tantalum capacitors, 2.2µF or more and a larger case size may be needed to maintain ESR in the stable region. For a pin-compatible, functionally equivalent device for use with a higher ESR output capacitor, see the MAX8885. A graph of the Region of Stable COUT ESR vs. Load Current is shown in the Typical Operating Characteristics. PSRR and Operation from Sources Other than Batteries The MAX8875 is designed to deliver low dropout voltages and low quiescent currents in battery-powered systems. Power-supply rejection is 60dB at low frequencies. See the Power-Supply Rejection Ratio vs. Frequency graph in the Typical Operating Characteristics. Improve supply-noise rejection and transient response by increasing the values of the input and output bypass capacitors. The Typical Operating Characteristics show the MAX8875’s line- and load-transient responses. Dropout Voltage A regulator’s minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this will determine the useful end-of-life battery voltage. Because the MAX8875 uses a P-channel MOSFET pass transistor, its dropout voltage is a function of drain-to-source on-resistance (RDS(ON)) multiplied by the load current (see Typical Operating Characteristics): VDROPOUT = VIN - VOUT = RDS(ON) · IOUT Chip Information TRANSISTOR COUNT: 266 _______________________________________________________________________________________ 7 MAX8875 Current Limit The MAX8875 includes a current limiter that monitors and controls the pass transistor’s gate voltage, limiting the output current to 390mA (typ). For design purposes, consider the current limit to be 160mA min to 600mA max. The output can be shorted to ground for an indefinite period of time without damaging the part. 150mA, Low-Dropout Linear Regulator with Power-OK Output SOT5L.EPS MAX8875 Package Information 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. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.