19-1859; Rev 0; 12/00 Low-Dropout, 300mA Linear Regulators in SOT23 ________________________Applications Notebook Computers Wireless Handsets Features ♦ Guaranteed 300mA Ouput Current (500mA for pulsed loads) ♦ Low 100mV Dropout at 200mA Load ♦ POK Output (MAX8888) ♦ 42µVRMS Ouput Noise (MAX8887) ♦ Preset Output Voltages (1.5V, 1.8V, 2.85V, and 3.3V) ♦ 55µA No-Load Supply Current ♦ Thermal-Overload and Short–Circuit Protection ♦ Foldback Ouput Current-Limit Protection ♦ 60dB PSRR at 1kHz ♦ 0.1µA Shutdown Current ♦ Thin 5-Pin SOT23 Package, 1mm High Ordering Information PART TEMP RANGE PINPACKAGE TOP MARK MAX8887EZK15 -40°C to +85°C 5-SOT23 ADQD MAX8887EZK18 -40°C to +85°C 5-SOT23 ADPX MAX8887EZK29 -40°C to +85°C 5-SOT23 ADPY ADPZ MAX8887EZK33 -40°C to +85°C 5-SOT23 PDAs and Palmtop Computers MAX8887EZKxy* -40°C to +85°C 5-SOT23 – Digital Cameras MAX8888EZK15 -40°C to +85°C 5-SOT23 ADQE PCMCIA Cards MAX8888EZK18 -40°C to +85°C 5-SOT23 ADQA Hand-Held Instruments MAX8888EZK29 -40°C to +85°C 5-SOT23 ADQB MAX8888EZK33 -40°C to +85°C 5-SOT23 ADQC MAX8888EZKxy* -40°C to +85°C 5-SOT23 – Typical Operating Circuit *Other versions (xy) between +1.5 and +3.3V are available in 100mV increments. Contact factory for other versions. Minimum order quantity is 25,000 units. Pin Configurations VOUT 300mA INPUT +2.5V TO +5.5V IN CIN 2.2µF OUT COUT 2.2µF MAX8887 MAX8888 TOP VIEW IN 1 5 OUT IN 1 5 OUT 4 POK POK ON SHDN GND 2 (BP) OFF GND MAX8887 GND 2 MAX8888 CBP 0.01µF SHDN 3 4 BP SHDN 3 ( ) ARE FOR MAX8887 ONLY. ________________________________________________________________ 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. MAX8887/MAX8888 General Description The MAX8887/MAX8888 low-dropout linear regulators operate from a +2.5V to +5.5V input and deliver up to 300mA continuous (500mA pulsed) current. The MAX8887 is optimized for low-noise operation, while the MAX8888 includes an open-drain POK ouput flag. Both regulators feature exceptionally low 100mV dropout at 200mA. These devices are available in a variety of preset output voltages in the +1.5V to +3.3V range. An internal PMOS pass transistor allows the low 55µA supply current to remain independent of load, making these devices ideal for portable battery-powered equipment such as personal digital assistants (PDAs), cellular phones, cordless phones, and notebook computers. Other features include a micropower shutdown mode, short-circuit protection, thermal shutdown protection, and an active-low open-drain power-OK (POK) output that indicates when the output is out of regulation. The MAX8887/MAX8888 are available in a thin 5-pin SOT23 package that is only 1mm high. MAX8887/MAX8888 Low-Dropout, 300mA Linear Regulators in SOT23 ABSOLUTE MAXIMUM RATINGS IN, SHDN, POK, to GND........................................-0.3V to +6.0V OUT, BP to GND ............................................-0.3 to (VIN + 0.3V) Output Short-Circuit Duration.....................................Continuous Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 9.1mW/°C above +70°C)............727mW Operating Temperature Ranges..........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+500°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 + 1V, SHDN = IN, TA = -40°C to +85°C, unless otherwise noted.) (Note 1) PARAMETER Input Voltage Input Undervoltage Lockout Output Voltage Accuracy SYMBOL CONDITIONS VIN Current Limit Ground-Pin Current MAX UNITS 2.5 5.5 V 2.15 2.4 V TA = +25°C, IOUT = 100mA -1.2 +1.2 -2 +2 -3 +3 IOUT = 100µA to 300mA, TA = 0°C to +85°C Continuous 300 10ms pulse VOUT = 0 300 VOUT > 93% of nominal value 420 mA No load 55 IOUT = 300mA IOUT = 1mA 65 0.5 IOUT = 200mA 100 IOUT = 300mA 150 VOUT = +3.3V Line Regulation VIN =2.5V or (VOUT + 0.4V) to 5.5V, IOUT = 5mA -0.15 0 MAX8887 10Hz to 100kHz, CBP = 0.01µF, COUT = 2.2µF, ESRCOUT < 0.1Ω 42 MAX8888 10Hz to 100kHz, COUT = 2.2µF, ESRCOUT < 0.1Ω 360 MAX8887 f < 1kHz, CBP = 0.01µF, COUT = 4.7µF, ESRCOUT < 0.1Ω 60 MAX8888 f < 1kHz, COUT = 2.2µF, ESRCOUT < 0.1Ω 40 Output Noise PSRR % mA 500 Dropout Voltage (Note 2) 2 TYP VIN rising (2% typical hysteresis) IOUT = 100µA to 300mA Maximum Output Current MIN 100 µA 200 mV 0.15 %/V µVRMS dB _______________________________________________________________________________________ Low-Dropout, 300mA Linear Regulators in SOT23 (VIN = VOUT + 1V, SHDN = IN, TA = -40°C to +85°C, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 0.1 2 µA SHUTDOWN SHDN = GND, VIN = 5.5V Shutdown Supply Current SHDN Input Threshold VIH 2.5V ≤ VIN ≤ 5.5V VIL 2.5V ≤ VIN ≤ 5.5V 1.6 V 0.6 SHDN Input Bias Current SHDN = IN or GND 10 100 nA OUT Discharge Resistance in Shutdown SHDN = GND 650 1100 Ω 92.5 95 % 5.5 V ISINK = 1mA 0.1 V VPOK = 5.5V, SHDN = IN 100 nA POK (MAX8888 ONLY) POK Trip Level, Referred to OUT Set Point VOUT falling (1% typical hysteresis) 90 Operating IN Voltage Range for Valid POK 1.0 POK Output Voltage Low VOL POK Output Leakage Current THERMAL PROTECTION Thermal Shutdown Temperature 170 °C Thermal Shutdown Hysteresis 20 °C Note 1: All parts are 100% tested at TA = +25°C. Limits over the operating temperature range are guaranteed by design. Note 2: Typical and maximum dropout voltage for different output voltages are shown in Typical Operating Characteristics curve. Typical Operating Characteristics (Typical Operating Circuit, TA = +25°C, unless otherwise noted.) OUTPUT VOLTAGE ACCURACY vs. LOAD CURRENT 0.8 0.6 2.0 1.5 1.0 0.5 2.0 2.5 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 5.0 5.5 0.03 0.02 0.4 0.2 0.0 -0.2 0.01 0.0 -0.01 -0.4 -0.02 -0.6 -0.03 -0.8 -0.04 -1.0 0 IOUT = 0 VIN = VOUT + 500mV 0.04 % DEVIATION % DEVIATION (%) OUTPUT VOLTAGE (V) IOUT = 300mA 2.5 0.05 MAX8887-8 toc02 IOUT = 0 3.0 1.0 MAX8887-8 toc01 3.5 OUTPUT VOLTAGE ACCURACY vs. TEMPERATURE MAX8887-8 toc03 OUTPUT VOLTAGE vs. INPUT VOLTAGE -0.05 0 50 100 150 200 LOAD CURRENT (mA) 250 300 -40 -15 10 35 60 85 TEMPERATURE (°C) _______________________________________________________________________________________ 3 MAX8887/MAX8888 ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (continued) (Typical Operating Circuit, TA = +25°C, unless otherwise noted.) DROPOUT VOLTAGE vs. OUTPUT VOLTAGE MAXIMUM VDROPOUT (mV) TA = +85°C 100 80 60 200 150 TYPICAL 100 TA = -40°C 40 50 20 0 50 100 150 200 250 100 ILOAD = 300mA 75 50 ILOAD = 0 0 2.5 300 125 25 0 0 MAX8887-8 toc06 IOUT = 200mA 250 GROUND-PIN CURRENT vs. INPUT VOLTAGE 150 GROUND-PIN CURRENT (µA) TA = +25°C 120 2.7 2.9 3.1 3.3 0 1.0 2.0 3.0 4.0 VOUT (V) INPUT VOLTAGE (V) GROUND-PIN CURRENT vs. LOAD CURRENT GROUND-PIN CURRENT vs. TEMPERATURE POWER-SUPPLY REJECTION RATIO vs. FREQUENCY VIN = +3.8V 60 40 20 70 66 60 64 COUT = 2.2µF CBP = 0.01µF 50 62 60 58 56 MAX8887-8 toc09 80 IOUT = 0 VIN = VOUT + 500mV 68 PSRR (dB) VIN = +5.5V 70 GROUND-PIN CURRENT (µA) MAX8887-8 toc07 100 40 30 20 54 0 50 0 50 100 150 200 250 300 VOUT = +3.30V ILOAD = 30mA 10 52 -40 LOAD CURRENT (mA) -15 10 35 60 85 0 0.01 0.1 TEMPERATURE (°C) MAX8887 OUTPUT NOISE DC TO 1MHz MAX8887 ONLY 1 10 FREQUENCY (kHz) LOAD-TRANSIENT RESPONSE MAX8887-9 toc10 MAX8887-9 toc11 300mA IOUT 10mA VOUT 50mV/div AC-COUPLED VOUT 50µV/div VOUT = +3.3V VIN = +3.8V VOUT = +1.8V, VIN = 3.8V, ILOAD = 15mA TIME (40ms/div) 4 5.0 LOAD CURRENT (mA) MAX8887-8 toc08 VDROPOUT (mV) MAX8887-8 toc04 140 300 MAX8887-8 toc05 DROPOUT VOLTAGE vs. LOAD CURRENT 160 GROUND-PIN CURRENT (µA) MAX8887/MAX8888 Low-Dropout, 300mA Linear Regulators in SOT23 TIME (10µs/div) _______________________________________________________________________________________ 100 1000 Low-Dropout, 300mA Linear Regulators in SOT23 LOAD-TRANSIENT RESPONSE NEAR DROPOUT LINE-TRANSIENT RESPONSE MAX8887-9 toc13 MAX8887-9 toc12 300mA +4.5V IOUT 10mA VIN +4V VOUT 50mV/div AC-COUPLED VOUT 20mV/div AC-COUPLED VOUT = +3.3V VIN = +3.4V VOUT = +3.3V ILOAD = 100mA TIME (100µs/div) TIME (10µs/div) POK WAVEFORM SHUTDOWN WAVEFORM MAX8887-9 toc15 MAX8887-9 toc14 VSHDN VIN VOUT = +3.3V, RLOAD = 100Ω 2V/div 2V/div VOUT 1V/div DC-COUPLED VOUT 2V/div VPOK 2V/div VOUT = +3.3V, RLOAD = 10Ω TIME (20µs/div) TIME (20ms/div) Pin Description MAX8887 MAX8888 NAME 1 1 IN 2 2 GND 3 3 SHDN — 4 POK 4 — BP 5 5 OUT FUNCTION Regulator Input. Supply voltage can range from 2.5V to 5.5V. Bypass with 2.2µF capacitor to GND (see Capacitor Selection and Regulator Stability). Ground Active-Low Shutdown Input. A logic low reduces the supply current to below 0.1µA. In shutdown, POK and OUT are driven low. Connect to IN for normal operation. Open-Drain Active-Low POK Output. POK remains low while the output voltage (VOUT) is below the reset threshold. Connect a 100kΩ pullup resistor to OUT to obtain a logic level output. POK is driven low in shutdown. If not used, leave this pin unconnected. Reference Bypass. Bypass with a low-leakage 0.01µF ceramic capacitor. Regulator Output. Sources up to 300mA guaranteed. Bypass with 2.2µF (<0.2Ω typical ESR) ceramic capacitor to GND. _______________________________________________________________________________________ 5 MAX8887/MAX8888 Typical Operating Characteristics (continued) (Typical Operating Circuit, TA = +25°C, unless otherwise noted.) MAX8887/MAX8888 Low-Dropout, 300mA Linear Regulators in SOT23 Detailed Description The MAX8887/MAX8888 are low-dropout, low-quiescent-current linear regulators designed primarily for battery-powered applications. The devices supply loads up to 300mA and are available in several fixed output voltages in the +1.5 to +3.3V range. The MAX8887 is optimized for low-noise operation, while the MAX8888 includes an open-drain POK output flag. As illustrated in Figure 1, the MAX8888 consists of a 1.25V reference, error amplifier, P-channel pass transistor, and internal feedback voltage divider. Internal P-Channel Pass Transistor The MAX8887/MAX8888 feature a 0.5Ω P-channel MOSFET pass transistor. Unlike similar designs using PNP pass transistors, P-channel MOSFETs require no base drive, which reduces quiescent current. PNPbased regulators also waste considerable current in dropout when the pass transistor saturates and use high base drive currents under large loads. The MAX8887/MAX8888 do not suffer from these problems and consume only 55µA of quiescent current under heavy loads as well as in dropout. Ouput Voltage Selection The MAX8887/MAX8888 are supplied with various factory-set output voltages ranging from 1.5V to 3.3V. The part number’s two-digit suffix identifies the nominal output voltage. For example, the MAX8887EUK33 has a preset output voltage of 3.3V (see Ordering Information). Shutdown Drive SHDN low to enter shutdown. During shutdown, the output is disconnected from the input and supply current drops to 0.1µA. When in shutdown, POK and OUT are driven low. SHDN can be pulled as high as 6V, regardless of the input and output voltages. Power-OK Output The power-OK output (POK) pulls low when OUT is less than 93% of the nominal regulation voltage. Once OUT exceeds 93% of the nominal voltage, POK goes high impedance. POK is an open-drain N-channel output. To obtain a logic level output, connect a pullup resistor from POK to OUT. A 100kΩ resistor works well for most applications. POK can be used as a power-on-reset (POR) signal to a microcontroller (µC) or to drive other logic. Adding a capacitor from POK to ground creates POK delay. When the MAX8887 is shut down, POK is held low independent of the output voltage. If unused, leave POK grounded or unconnected. Current Limit The MAX8887/MAX8888 monitor and control the pass transistor’s gate voltage, limiting the output current to 6 0.8A (typ). This current limit is reduced to 500mA (typ) when the output voltage is below 93% of the nominal value to provide foldback current limiting. Thermal-Overload Protection Thermal-overload protection limits total power dissipation in the MAX8887/MAX8888. When the junction temperature exceeds TJ =+170°C, a thermal sensor turns off the pass transistor, allowing the device to cool. The thermal sensor turns the pass transistor on again after the junction temperature cools by 20°C, resulting in a pulsed output during continuous thermal overload conditions. Thermal overload protection protects the MAX8887/MAX8888 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 MAX8887/MAX8888’s maximum power dissipation depends on the thermal resistance of the IC package and circuit board. The temperature difference between the die junction and ambient air, and the rate of air flow. The power dissipated in the device is P = IOUT ✕ (VINV OUT ). The maximum allowed power dissipation is 727mW or: PMAX = (TJ(MAX) - TA) / (θJC + θCA) where T J(MAX) -T A is the temperature difference between the MAX8887/MAX8888 die junction and the surrounding air; θJC is the thermal resistance from the junction to the case; and θCA is the thermal resistance from the case through PC board, copper traces, and other materials to the surrounding air. Refer to Figure 2 for the MAX8887/MAX888 valid operating region. Noise Reduction For the MAX8887 only, an external 0.01µF bypass capacitor at BP creates a lowpass filter for noise reduction. The MAX8887 exhibits 42µVRMS of output voltage noise with C BP = 0.01µF and C OUT = 2.2µF (see Typical Operating Characteristics). Applications Information Capacitor Selection and Regulator Stability Connect a 2.2µF ceramic capacitor between IN and ground and a 2.2µF ceramic capacitor between OUT and ground. The input capacitor (C IN ) lowers the source impedance of the input supply. Reduce noise and improve load-transient response, stability, and power-supply rejection by using a larger ceramic output capacitor such as 4.7µF. The output capacitor’s (COUT) equivalent series resistance (ESR) affects stability and output noise. Use out- _______________________________________________________________________________________ Low-Dropout, 300mA Linear Regulators in SOT23 MAX8887/MAX8888 IN SHDN P MOS DRIVER WITH ILIMIT ERROR AMP SHUTDOWN LOGIC OUT MAX8888 POK THERMAL SENSOR 1.25V REF POK 95% REF GND Figure 1. Functional Diagram Input-Output (Dropout) Voltage A regulator’s minimum input-to-output voltage differential (dropout voltage) determines the lowest usable supply voltage at which the output is regulated. In battery-powered systems, this determines the useful end-of-life battery voltage. The MAX8887/MAX8888 use 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 400 TA = +85°C TA = +70°C MAXIMUM RECOMMENDED OUTPUT CURRENT 300 2.0 2.5 VOUT = +1.8V 100 VOUT = +3.3V 200 VOUT = +2.85V Noise, PSRR, and Transient Response The MAX8887/MAX8888 are designed to operate with low dropout voltages and low quiescent currents in battery-powered systems while still maintaining excellent noise, transient response, and AC rejection. See the Typical Operating Characteristics for a plot of powersupply rejection ratio (PSRR) versus frequency. When operating from noisy sources, improved supply-noise rejection and transient response can be achieved by increasing the values of the input and output bypass capacitors and through passive filtering techniques. MAXIMUM OUTPUT CURRENT vs. INPUT VOLTAGE (POWER DISSIPATION LIMIT) MAXIMUM OUTPUT CURRENT (mA) put capacitors with an ESR of 0.1Ω or less to ensure stability and optimum transient response. Surface-mount ceramic capacitors have very low ESR and are commonly available in values up to 10µF. Connect CIN and COUT as close to the MAX8887/MAX8888 as possible to minimize the impact of PC board trace inductance. 0 0 0.5 1.0 1.5 3.0 3.5 4.0 (VIN - VOUT) (V) Figure 2. Power Operating Regions: Maximum Output Current vs. Input Voltage Chip Information TRANSISTOR COUNT: 620 PROCESS: BiCMOS _______________________________________________________________________________________ 7 Low-Dropout, 300mA Linear Regulators in SOT23 THIN SOT23.EPS MAX8887/MAX8888 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 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.