19-1556; Rev 1; 12/00 150mA, Low-Dropout Linear Regulator with Power-OK Output 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. 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 Ordering Information PART* TEMP. RANGE PIN-PACKAGE MAX8875EUKxy-T -40°C to +85°C 5 SOT23-5 *xy is the output voltage code (see Output Voltage Selector Guide). Applications Output Voltage Selector Guide PCS Telephones Hand-Held Instruments Cellular Telephones Palmtop Computers MAX8875EUK15-T 1.5 ADQI Cordless Telephones Electronic Planners MAX8875EUK25-T 2.5 ADKZ PCMCIA Cards Modems MAX8875EUK27-T MAX8875EUK30-T MAX8875EUK33-T 2.7 3.0 3.3 ADLA ADLB ADLC MAX8875EUK50-T 5.0 ADLD Typical Operating Circuit VOUT (V) OUT COUT 1µF CIN 1µF TOP MARK Note: Other output voltages between 1.5V and 5.0V are available in 100mV increments—contact the factory for information. Minimum order quantity is 25,000 units. OUTPUT PRESET 1.5V TO 5.0V 150mA INPUT +2.5V TO +6.5V IN PART Pin Configuration TOP VIEW IN 1 5 OUT 4 POK MAX8875 100k GND 2 ON OFF POK SHDN GND MAX8875 TO µC SHDN 3 SOT23-5 ________________________________________________________________ Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 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 (POK) 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, 2.5V, or 1.5V. 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 VIN TA = -40°C to +85°C MAX UNITS 2.5 6.5 V -1.0 1.0 -2 2 IOUT = 100µA to 120mA -3 2 Maximum Output Current IOUT 150 Current Limit ILIM 160 Ground Pin Current Dropout Voltage (Note 2) IQ VIN - VOUT TYP IOUT = 100µA TA = +25°C, IOUT = 100µA Output Voltage Accuracy MIN % mA 390 IOUT = 100µA 85 IOUT = 150mA 100 IOUT = 100µA 0.1 IOUT = 50mA 50 IOUT = 100mA 110 IOUT = 150mA 165 mA 180 220 µA mV Line Regulation ∆VLNR VIN = 2.5V or (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 2 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 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 CONDITIONS MIN TYP MAX -3 -5 -8 TA = 0°C to +85°C -8.5 -10.5 -13.5 TA = -40°C to +85°C -7 UNITS POWER-OK OUTPUT 1 - VOUT / VOUT(NOMINAL) 100, IOUT = 0, VOUT falling, VOUT ≥ 2.5V Power-OK Voltage Threshold VPOK 1 - VOUT /VOUT(NOMINAL) 100, IOUT = ILIM, VOUT falling, VOUT < 2.5V % In dropout, VOUT falling, VOUT ≥ 2.5V -5.3 1 Hysteresis, IOUT = 0 POK Output Voltage Low VOL -15 ISINK = 1mA 0 ≤ VPOK ≤ 6.5V, VOUT in regulation POK Output Leakage Current 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. Applies only for output voltages ≥ 2.5V. Typical Operating Characteristics (MAX8875EUK30, VIN = +3.6V, CIN = COUT = 1µF, SHDN = IN, TA = +25°C, unless otherwise noted.) GROUND PIN CURRENT vs. OUTPUT LOAD GROUND PIN CURRENT (µA) 80 IOUT = 0 60 40 110 VIN = 5.0V 105 100 VIN = 3.5V 95 90 20 0 1 2 3 4 INPUT VOLTAGE (V) 5 6 VIN = VOUT(NOMINAL) + 0.5V 115 VOUT = 5.0V MAX8875EUK50 110 105 100 VOUT = 3.0V MAX8875EUK30 95 90 85 0 120 MAX8875toc03 100 115 MAX8875toc02 IOUT = 150mA GROUND PIN CURRENT (µA) MAX8875toc01 120 GROUND PIN CURRENT vs. OUTPUT LOAD GROUND PIN CURRENT (µA) GROUND PIN CURRENT vs. INPUT VOLTAGE 85 0 15 30 45 60 75 90 105 120 135 150 OUTPUT LOAD (mA) 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.) OUTPUT VOLTAGE vs. INPUT VOLTAGE VIN = 3.6V IOUT = 150mA 90 VIN = 3.6V OR 5.0V IOUT = 0 80 2.5 2.0 IOUT = 150mA 1.5 1.0 3.05 3.00 VIN = 3.6V 2.95 VIN = 5.0V 0.5 70 2.90 0 60 -40 -15 10 35 60 0 85 1 2 3 4 5 0 6 15 30 45 60 75 90 105 120 135 150 TEMPERATURE (°C) INPUT VOLTAGE (V) OUTPUT LOAD (mA) OUTPUT VOLTAGE vs. TEMPERATURE DROPOUT VOLTAGE vs. OUTPUT LOAD POWER-SUPPLY REJECTION RATIO vs. FREQUENCY 3.00 VIN = 3.6V IOUT = 150mA 2.95 2.90 COUT = 10µF TA = +85°C TA = +25°C 100 -15 10 35 60 40 30 COUT = 1µF 20 TA = -40°C 10 0 85 0 15 0 0.01 30 45 60 75 90 105 120 135 150 0.1 1 10 FREQUENCY (kHz) OUTPUT NOISE SPECTRAL DENSITY vs. FREQUENCY OUTPUT NOISE LINE-TRANSIENT RESPONSE f = 10Hz TO 100kHz COUT = 10µF IOUT = 50mA VIN MAX8875toc10 COUT = 10µF IOUT = 50mA 5V 4V 1 VOUT 500µV/div 3.02V VOUT 0.1 3.00V 2.98V 0.01 1 10 FREQUENCY (kHz) 4 100 1000 MAX8875toc13 OUTPUT LOAD (mA) 10 0.1 100 TEMPERATURE (°C) MAX8875toc11 -40 60 50 150 50 VIN = 5.0V IOUT = 150mA MAX8875toc09 200 PSRR (dB) 3.05 DROPOUT VOLTAGE (mV) VIN = 3.6V OR 5.0V IOUT = 0 70 MAX8875toc08 250 MAX8875toc07 3.10 OUTPUT VOLTAGE (V) IOUT = 0 OUTPUT VOLTAGE (V) 110 100 3.0 3.10 MAX8875toc05 VIN = 5.0V IOUT = 150mA OUTPUT VOLTAGE (V) GROUND PIN CURRENT (µA) 120 OUTPUT VOLTAGE vs. OUTPUT LOAD 3.5 MAX8875toc04 130 MAX8875toc06 GROUND PIN CURRENT vs. TEMPERATURE OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) MAX8875 150mA, Low-Dropout Linear Regulator with Power-OK Output 10ms/div 10µs/div IOUT = 50mA _______________________________________________________________________________________ 150mA, Low-Dropout Linear Regulator with Power-OK Output MAX8875toc14 3.01V VOUT 3.00V 3.00V 2.99V 50mA 50mA ILOAD 2.99V ILOAD 0 0 10µs/div 10µs/div VIN = VOUT + 0.5V, IOUT = 0 TO 50mA VIN = VOUT + 0.1V, IOUT = 0 TO 50mA SHUTDOWN DELAY 3V MAX8875toc17 MAX8875toc16 POK OUTPUT VOUT 1V/div 0 0 0 2V VOUT 2V/div VPOK 2V/div 4V VSHDN 1V/div 0 VIN 1V/div 3V 2V 100µs/div 200µs/div MAX8875EUK30, ROUT = 60Ω RPOK = 100kΩ POK STARTUP RESPONSE POK AND SHUTDOWN RESPONSE MAX8875toc18 5.0V VIN 2.5V/div 0 MAX8875toc19 VOUT 3.01V MAX8875toc15 LOAD-TRANSIENT RESPONSE NEAR DROPOUT LOAD-TRANSIENT RESPONSE 2V VSHDN 2V/div 0 VOUT 2.5V/div 2.5V 0 2V VOUT 2V/div 0 4V 5.0V VPOK 2V/div VPOK 2.5V/div 0 0 RLOAD = 60Ω 10ms/div RPOK = 100kΩ 10µs/div RPOK = 100kΩ _______________________________________________________________________________________ 5 MAX8875 Typical Operating Characteristics (continued) (MAX8875EUK30, VIN = +3.6V, CIN = COUT = 1µF, SHDN = IN, TA = +25°C, unless otherwise noted.) 150mA, Low-Dropout Linear Regulator with Power-OK Output MAX8875 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, 2.5V, or 1.5V output. Sources up to 150mA. Bypass with 1µF (<0.2Ω typical ESR) ceramic capacitor to GND for VOUT ≥ 2.5V. Bypass with 3.3µF (<0.2Ω typ ESR) ceramic capacitor to GND for VOUT = 1.5V. 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). IN SHDN REVERSEBATTERY PROTECTION MOS DRIVER WITH ILIMIT ERROR AMP SHUTDOWN LOGIC P OUT MAX8875 POK THERMAL SENSOR 1.25V REF 95% REF POK 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 1.5V, 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 6 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. _______________________________________________________________________________________ 150mA, Low-Dropout Linear Regulator with Power-OK Output 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 (POK) 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. 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. 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 for VOUT ≥ 2.5V, or an equivalent 3.3µF ceramic output capacitor for VOUT = 1.5V. To reduce noise and improve loadtransient 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 increase the capacitance by a factor of 2 or more to ensure stability at temperatures below TA = -10°C. With X7R or X5R dielectrics, 1µF should be sufficient at all operating temperatures for VOUT ≥ 2.5V. For a pin-compatible, functionally equivalent device for use with a higher ESR output capacitor, see the MAX8885. _______________________________________________________________________________________ 7 MAX8875 Output Voltage The MAX8875 is supplied with factory-set output voltages of 1.5V, 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). MAX8875 150mA, Low-Dropout Linear Regulator with Power-OK Output 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 For versions with the output voltage greater than the minimum input voltage (2.5V), the regulator’s minimum input-output voltage differential (or dropout voltage) determines the lowest usable supply voltage. In batterypowered systems, this will determine the useful end-oflife 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 8 _______________________________________________________________________________________ 150mA, Low-Dropout Linear Regulator with Power-OK Output SOT5L.EPS 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. 9 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX8875 Package Information