19-1301; Rev 1; 3/98 Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout ____________________________Features ♦ Pin-Compatible with the Industry-Standard ‘2982 ________________________Applications ♦ Low Output Noise: 30µVRMS ♦ Low 55mV Dropout at 50mA Output (165mV at 150mA output) ♦ Low 85µA No-Load Supply Current ♦ Low 100µA Operating Supply Current (even in dropout) ♦ Thermal-Overload and Short-Circuit Protection ♦ Reverse Battery Protection ♦ Output Current Limit ♦ Preset Output Voltages (±1.4% Accuracy) ♦ 10nA Logic-Controlled Shutdown _________________Ordering Information Cellular Telephones TEMP. RANGE PART** Cordless Telephones PCS Telephones MAX8877EUKxy-T MAX8878C/Dxy MAX8878EUKxy-T PCMCIA Cards Modems Hand-Held Instruments PIN-PACKAGE 0°C to +70°C MAX8877C/Dxy Dice* -40°C to +85°C 0°C to +70°C -40°C to +85°C 5 SOT23-5 Dice* 5 SOT23-5 *Dice are tested at TA = +25°C only. ** xy is the output voltage code (see Expanded Ordering Information table at end of data sheet). Palmtop Computers Electronic Planners ____________Typical Operating Circuit _____________________Pin Configuration TOP VIEW INPUT 2.5V TO 6.5V IN CIN 1µF OUT MAX8877 MAX8878 ON COUT 1µF OUTPUT PRESET 2.5V TO 5.0V 150mA IN 1 GND 2 5 OUT 4 BP MAX8877 MAX8878 SHDN OFF SHDN 3 BP CBP 0.01µF 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 408-737-7600 ext. 3468. MAX8877/MAX8878 __________________General Description The MAX8877/MAX8878 low-noise, low-dropout linear regulators operate from a 2.5V to 6.5V input and deliver up to 150mA. These devices are pin-compatible with the industry-standard ‘2982 and offer an improved dropout voltage. Typical output noise is 30µVRMS, and typical dropout is only 165mV at 150mA. The output voltage is preset to voltages in the range of 2.5V to 5.0V, in 100mV increments. Designed with an internal P-channel MOSFET pass transistor, the MAX8877/MAX8878 maintain a low 100µA supply current, independent of the load current and dropout voltage. Other features include a 10nA logic-controlled shutdown mode, short-circuit and thermal-shutdown protection, and reverse battery protection. The MAX8878 also includes an auto-discharge function, which actively discharges the output voltage to ground when the device is placed in shutdown. Both devices come in a miniature 5-pin SOT23 package. MAX8877/MAX8878 Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout ABSOLUTE MAXIMUM RATINGS IN to GND ....................................................................-7V to +7V Output Short-Circuit Duration ............................................Infinite SHDN to GND..............................................................-7V to +7V SHDN to IN ...............................................................-7V to +0.3V OUT, BP to GND ..........................................-0.3V to (VIN + 0.3V) Continuous Power Dissipation (TA = +70°C) SOT23-5 (derate 7.1mW/°C above +70°C)..................571mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C θJB ..................................................................................140°C/W Storage Temperature.........................................-65°C to +160°C Lead Temperature (soldering, 10sec) .............................+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) + 0.5V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Input Voltage SYMBOL CONDITIONS VIN IOUT = 0mA, TA = +25°C Output Voltage Accuracy IOUT = 0mA to 120mA, TA = -40°C to +85°C Maximum Output Current Current Limit Ground Pin Current TYP MAX UNITS V 2.5 6.5 -1.4 1.4 -3 2 150 ILIM IQ Dropout Voltage (Note 2) 160 85 IOUT = 150mA 100 IOUT = 1mA 1.1 IOUT = 50mA 55 IOUT = 150mA 165 ∆VLNR VIN = (VOUT + 0.1V) to 6.5V, IOUT = 1mA Load Regulation ∆VLDR IOUT = 0mA to 120mA, COUT = 1µF en f = 10Hz to 100kHz, CBP = 0.01µF VIH VIN = 2.5V to 5.5V VIL VIN = 2.5V to 5.5V -0.15 % mA 390 No load Line Regulation Output Voltage Noise MIN mA 180 120 µA mV 0 0.15 %/V 0.01 0.04 %/mA COUT = 10µF 30 COUT = 100µF 20 µVRMS SHUTDOWN SHDN Input Threshold SHDN Input Bias Current ISHDN Shutdown Supply Current IQ(SHDN) VSHDN = VIN VOUT = 0V Shutdown Exit Delay (Note 3) CBP = 0.1µF COUT = 1µF, no load Resistance Shutdown Discharge MAX8878 only 2.0 V 0.4 TA = +25°C 0.01 TA = +85°C 0.5 TA = +25°C 0.01 TA = +85°C 0.2 TA = +25°C 30 TA = -40°C to +85°C 100 1 150 300 nA µA µs 300 Ω TSHDN 155 °C ∆TSHDN 15 °C THERMAL PROTECTION Thermal Shutdown Temperature Thermal Shutdown Hysteresis 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: The dropout voltage is defined as VIN - VOUT, when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V. Note 3: Time needed for VOUT to reach 95% of final value. 2 _______________________________________________________________________________________ Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout 2.50 2.45 MAX8877-02 110 105 GROUND PIN CURRENT (µA) MAX8877-01 2.55 GROUND PIN CURRENT vs. LOAD CURRENT 5.2 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 2.60 OUTPUT VOLTAGE vs. LOAD CURRENT (MAX887_EUK50) 5.1 5.0 4.9 MAX8877-03 OUTPUT VOLTAGE vs. LOAD CURRENT (MAX887_EUK25) MAX887_EUK50 100 95 MAX887_EUK25 90 85 80 75 70 65 4.8 50 100 150 100 150 LOAD CURRENT (mA) GROUND PIN CURRENT vs. INPUT VOLTAGE (MAX887_EUK25) GROUND PIN CURRENT vs. INPUT VOLTAGE (MAX887_EUK50) 80 NO LOAD 60 40 0 1 2 3 4 5 ILOAD = 50mA 100 80 NO LOAD 60 40 NO LOAD 5 MAX887_EUK50 4 3 2 MAX887_EUK25 1 0 0 6 1 2 3 4 5 6 0 1 2 3 4 5 INPUT VOLTAGE (V) INPUT VOLTAGE (V) INPUT VOLTAGE (V) OUTPUT VOLTAGE vs. TEMPERATURE (MAX887_EUK25) OUTPUT VOLTAGE vs. TEMPERATURE (MAX887_EUK50) GROUND PIN CURRENT vs. TEMPERATURE OUTPUT VOLTAGE (V) 2.55 ILOAD = 50mA 2.50 2.45 200 MAX8877-08 5.2 5.1 5.0 4.9 6 ILOAD = 50mA 180 GROUND PIN CURRENT (µA) ILOAD = 50mA MAX8877-07 2.60 150 OUTPUT VOLTAGE vs. INPUT VOLTAGE 0 0 100 6 20 20 50 LOAD CURRENT (mA) OUTPUT VOLTAGE (V) GROUND PIN CURRENT (µA) 100 0 MAX8877-05 120 MAX8877-04 ILOAD = 50mA GROUND PIN CURRENT (µA) 50 LOAD CURRENT (mA) 120 OUTPUT VOLTAGE (V) 60 0 MAX8877-06 0 MAX8877-09 2.40 160 140 MAX887_EUK50 120 100 80 MAX887_EUK25 60 40 20 2.40 4.8 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 0 -40 -20 0 20 40 60 TEMPERATURE (°C) 80 100 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) _______________________________________________________________________________________ 3 MAX8877/MAX8878 __________________________________________Typical Operating Characteristics (VIN = VOUT(NOMINAL) + 0.5V, CIN = 1µF, COUT = 1µF, CBP = 0.01µF, TA = +25°C, unless otherwise noted.) ____________________________Typical Operating Characteristics (continued) (VIN = VOUT(NOMINAL) + 0.5V, CIN = 1µF, COUT = 1µF, CBP = 0.01µF, TA = +25°C, unless otherwise noted.) TA = +25°C 150 TA = -40°C 100 60 TA = +85°C 150 MAX8877-12 MAX8877-11 70 COUT = 10µF 50 PSRR (dB) MAX8877-10 TA = +85°C 200 200 DROPOUT VOLTAGE (mV) DROPOUT VOLTAGE (mV) 250 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY DROPOUT VOLTAGE vs. LOAD CURRENT (MAX887_EUK50) TA = +25°C 100 TA = -40°C 40 30 COUT = 1µF 20 50 50 10 0 0 0 40 60 80 100 120 140 160 0 20 LOAD CURRENT (mA) 40 60 80 1 COUT = 1µF 0.1 COUT = 10µF ILOAD = 10mA f = 10Hz to 100kHz 70 60 50 MAX887_EUK50 40 MAX887_EUK30 30 100 1000 MAX887_EUK50 50 0.001 FREQUENCY (kHz) 0.01 MAX887_EUK30 30 20 MAX887_EUK25 COUT = 10µF CBP = 0.01µF f = 10Hz to 100kHz 1 0.1 10 REGION OF STABLE COUT ESR vs. LOAD CURRENT MAX8877-17 MAX8877-16 100 COUT ESR (Ω) 10 VOUT 50µV/div 100 LOAD CURRENT (mA) BP CAPACITANCE (µF) OUTPUT NOISE 10Hz TO 100kHz COUT = 10µF 1 COUT = 1µF STABLE REGION 0.1 0.01 1ms/div MAX887_EUK25, COUT = 10µF, ILOAD = 10mA, CBP = 0.1µF 4 1000 40 0 0 10 60 10 10 0.01 100 20 MAX887_EUK25 COUT = 10µF 10 OUTPUT NOISE vs. LOAD CURRENT OUTPUT NOISE vs. BP CAPACITANCE OUTPUT NOISE (µVRMS) CBP = 0.01µF ILOAD = 10mA 1 FREQUENCY (kHz) 80 MAX8877-13 10 1 0.1 LOAD CURRENT (mA) OUTPUT NOISE SPECTRAL DENSITY vs. FREQUENCY 0 0.01 100 120 140 160 MAX8877-14 20 OUTPUT NOISE (µVRMS) 0 ILOAD = 50mA CBP = 0.1µF MAX8877-15 DROPOUT VOLTAGE vs. LOAD CURRENT (MAX887_EUK25) OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) MAX8877/MAX8878 Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout 0 100 150 LOAD CURRENT (mA) _______________________________________________________________________________________ 1000 Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout LINE-TRANSIENT RESPONSE 4V MAX8877-20 MAX8877-19 VIN 3V LOAD-TRANSIENT RESPONSE NEAR DROPOUT LOAD-TRANSIENT RESPONSE MAX8877-18 3.01V VOUT 3.00V 2.99V 3.01V VOUT 3.00V 2.99V 3.001V VOUT 3.000V 50mA 50mA 2.999V ILOAD 10µs/div 10µs/div 100µs/div MAX887_EUK25 SHUTDOWN EXIT DELAY MAX887_EUK50 SHUTDOWN EXIT DELAY MAX8877-21 VSHDN CBP = 0.1µF 1V 0V 4V CBP = 0.01µF 5µs/div V SHDN 2V 0V 5V CBP = 0.1µF VOUT VOUT 2V 0V 0V MAX887_EUK25, ILOAD = 50mA MAX8877-23 VSHDN 2V 0V VOUT 2V ENTERING SHUTDOWN MAX8877-22 CBP = 0.01µF 0V MAX887_EUK30, VIN = VOUT + 0.1V, CIN = 10µF, ILOAD = 0mA TO 50mA MAX887_EUK30, VIN = VOUT + 0.5V, CIN = 10µF, ILOAD = 0mA TO 50mA MAX887_EUK30, ILOAD = 50mA 2V ILOAD 500µs/div 5µs/div MAX8878, NO LOAD MAX887_EUK50, ILOAD = 50mA ______________________________________________________________Pin Description PIN NAME FUNCTION 1 IN Regulator Input. Supply voltage can range from 2.5V to 6.5V. Bypass with a 1µF capacitor to GND (see Capacitor Selection and Regulator Stability section). 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 10nA. On the MAX8878, a logic low also causes the output voltage to discharge to GND. Connect to IN for normal operation. 4 BP 5 OUT Reference-Noise Bypass. Bypass with a low-leakage, 0.01µF ceramic capacitor for reduced noise at the output. Regulator Output. Sources up to 150mA. Bypass with a 1µF (<0.2Ω typical ESR) capacitor to GND. _______________________________________________________________________________________ 5 MAX8877/MAX8878 ____________________________Typical Operating Characteristics (continued) (VIN = VOUT(NOMINAL) + 0.5V, CIN = 1µF, COUT = 1µF, CBP = 0.01µF, TA = +25°C, unless otherwise noted.) MAX8877/MAX8878 Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout _______________Detailed Description The MAX8877/MAX8878 are low-noise, low-dropout, low-quiescent-current linear regulators designed primarily for battery-powered applications. The parts are available with preset output voltages ranging from 2.5V to 5V, in 100mV increments. These devices can supply loads up to 150mA. As illustrated in Figure 1, the MAX8877/MAX8878 consist of a 1.25V reference, error amplifier, P-channel pass transistor, 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 is fed back through an internal resistor voltage divider connected to the OUT pin. An external bypass capacitor connected to the BP pin reduces noise at the output. Additional blocks include a current limiter, reverse battery protection, thermal sensor, and shutdown logic. The MAX8878 also includes an auto-discharge function, which actively discharges the output voltage to ground when the device is placed in shutdown mode. IN SHDN Output Voltage The MAX8877/MAX8878 are supplied with factory-set output voltages from 2.5V to 5.0V, in 100mV increments. Except for the MAX887_EUK29 and the MAX887_EUK32 (which have an output voltage preset at 2.84V and 3.15V, respectively), the two-digit suffix allows the customer to choose the output voltage in 100mV increments. For example, the MAX8877EUK33 has a preset output voltage of 3.3V (see Expanded Ordering Information). Internal P-Channel Pass Transistor The MAX8877/MAX8878 feature a 1.1Ω typical 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 considerably. PNP-based regulators waste considerable current in dropout when the pass transistor saturates. They also use high base-drive currents under large loads. The MAX8877/MAX8878 do not suffer from these problems and consume only 100µA of quiescent current whether in dropout, light-load, or heavy-load applications (see the Typical Operating Characteristics). Current Limit The MAX8877/MAX8878 include a current limiter, which monitors and controls the pass transistor’s gate voltage, limiting the output current to 390mA. For design purposes, consider the current limit to be 160mA minimum to 500mA maximum. The output can be shorted to ground for an indefinite amount of time without damaging the part. REVERSE BATTERY PROTECTION MAX8877 MAX8878 ERROR AMP SHUTDOWN AND POWER-ON CONTROL P MOS DRIVER WITH ILIMIT * THERMAL SENSOR OUT N 1.25V REF GND BP * AUTO-DISCHARGE, MAX8878 ONLY Figure 1. Functional Diagram 6 _______________________________________________________________________________________ Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout Thermal-overload protection is designed to protect the MAX8877/MAX8878 in the event of fault conditions. For continual operation, do not exceed the absolute maximum junction-temperature rating of TJ = +150°C. Operating Region and Power Dissipation The MAX8877/MAX8878’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 MAX8877/MAX8878 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 GND pin of the MAX8877/MAX8878 performs the dual function of providing an electrical connection to ground and channeling heat away. Connect the GND pin to ground using a large pad or ground plane. Reverse Battery Protection The MAX8877/MAX8878 have a unique protection scheme that limits the reverse supply current to 1mA when either VIN or V SHDN falls below ground. Their 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. Noise Reduction An external 0.01µF bypass capacitor at BP, in conjunction with an internal 200kΩ resistor, creates a 80Hz lowpass filter for noise reduction. The MAX8877/MAX8878 exhibit 30µVRMS of output voltage noise with C BP = 0.01µF and COUT = 10µF. This is negligible in most applications. Start-up time is minimized by a power-on circuit that pre-charges the bypass capacitor. The Typical Operating Characteristics section shows graphs of Noise vs. BP Capacitance, Noise vs. Load Current, and Output Noise Spectral Density. ____________Applications Information Capacitor Selection and Regulator Stability Normally, use a 1µF capacitor on the MAX8877/ MAX8878’s input and a 1µF to 10µF capacitor on the output. Larger input capacitor values and lower ESRs provide better supply-noise rejection and line-transient response. Reduce noise and improve load-transient response, stability, and power-supply rejection by using large output capacitors. For stable operation over the full temperature range and with load currents up to 150mA, a minimum of 1µF is recommended. 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 -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 may be needed to maintain ESR in the stable region. A graph of the Region of Stable COUT ESR vs. Load Current is shown in the Typical Operating Characteristics. Use a 0.01µF bypass capacitor at BP for low output voltage noise. Increasing the capacitance will slightly decrease the output noise, but increase the start-up time. Values above 0.1µF provide no performance advantage and are not recommended (see Shutdown Exit Delay graphs in the Typical Operating Characteristics). PSRR and Operation from Sources Other than Batteries The MAX8877/MAX8878 are designed to deliver low dropout voltages and low quiescent currents in batterypowered systems. Power-supply rejection is 63dB at low frequencies and rolls off above 10kHz. See the Power-Supply Rejection Ratio Frequency graph in the Typical Operating Characteristics. When operating from sources other than batteries, 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. The Typical Operating Characteristics show the MAX8877/MAX8878’s line- and loadtransient responses. Load-Transient Considerations The MAX8877/MAX8878 load-transient response graphs (see Typical Operating Characteristics) show two components of the output response: a DC shift from the output impedance due to the load current change, and the transient response. Typical transient _______________________________________________________________________________________ 7 MAX8877/MAX8878 Thermal-Overload Protection Thermal-overload protection limits total power dissipation in the MAX8877/MAX8878. When the junction temperature exceeds T J = +155°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 15°C, resulting in a pulsed output during continuous thermal-overload conditions. for a step change in the load current from 0mA to 50mA is 12mV. Increasing the output capacitor’s value and decreasing the ESR attenuates the overshoot. ply voltage. In battery-powered systems, this will determine the useful end-of-life battery voltage. Because the MAX8877/MAX8878 use a P-channel MOSFET pass transistor, their dropout voltage is a function of drain-tosource on-resistance (RDS(ON)) multiplied by the load current (see Typical Operating Characteristics). Input-Output (Dropout) Voltage A regulator’s minimum input-output voltage differential (or dropout voltage) determines the lowest usable sup- ___________________Chip Information TRANSISTOR COUNT: 247 SUBSTRATE CONNECTED TO GND ____________________________________________Expanded Ordering Information SOT TOP MARK OUTPUT VOLTAGE (xy) CODE PRESET OUTPUT VOLTAGE (V) MAX8877 MAX887_EUK25-T 2.50 ACBM ACBT MAX887_EUK28-T 2.80 ACBN ACBU MAX887_EUK29-T 2.84 ACBO ACBV MAX887_EUK30-T 3.00 ACBP ACBW MAX887_EUK32-T 3.15 ACBQ ACBX MAX887_EUK33-T 3.30 ACBR ACBY MAX887_EUK36-T 3.60 ACDB ACDC MAX887_EUK50-T 5.00 ACBS ACBZ Other xy*** x.y0 — — MAX8878 ***Other xy between 2.5V and 5.0V are available in 100mV increments. Contact factory for other versions. Minimum order quantity is 25,000 units. ________________________________________________________Package Information SOT5L.EPS MAX8877/MAX8878 Low-Noise, Low-Dropout, 150mA Linear Regulators with ‘2982 Pinout 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 © 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.