MAX8896 19-4663 Rev 0 5/09 Dual PWM Step-Down Converter in a 2mm x 2mm Package for WCDMA PA and RF Power General Description Features The MAX8896 dual step-down converter is optimized PA Step-Down Converter (OUT1) for powering the power amplifier (PA) and RF transceiv- 7.5s (typ) Settling Time for 0.5V to 1V Output er in WCDMA handsets. This device integrates a high- Voltage Change efficiency PWM step-down converter (OUT1) for Dynamic Output Voltage Setting from 0.5V to medium and low-power transmission, and a 140m V BATT (typ) bypass FET to power the PA directly from the bat- 140m Bypass PFET and 100% Duty Cycle tery during high-power transmission. A second high- for Low Dropout efficiency PWM step-down converter (OUT2) supplies 2MHz Switching Frequency power directly to a high PSRR, low output noise, 200mA Low Output Voltage Ripple low-dropout linear regulator (LDO) to power the RF 700mA (min) Output Drive Capability transceiver. 2% Gain Accuracy Fast switching allows the use of small ceramic input and Tiny External Components output capacitors while maintaining low ripple voltage. RF Step-Down Converter (OUT2) The feedback network is integrated reducing external 2MHz Fixed Switching Frequency component count and total solution size. OUT1 uses an analog input driven by an external DAC to control the 94% Peak Efficiency output voltage linearly for continuous PA power adjust- 100% Duty Cycle ment. At high duty cycle, OUT1 automatically switches to 2% Output Accuracy Over Load, Line, and bypass mode, connecting the input to the output through Temperature a low-impedance (140m, typ) MOSFET. 200mA (min) Output Drive Capability OUT2 is a 2MHz fixed-frequency, step-down converter Tiny External Components capable of operating at 100% duty cycle. Output accu- Low-Noise LDO racy is 2% over load, line, and temperature. The out- Guaranteed 200mA Output put of OUT2 is preset to 3.1V to provide power to a High 65dB (typ) PSRR 200mA, 2.8V LDO designed for low noise (16V , RMS Fixed Output Voltage typ), high PSRR (65dB, typ) operation. This configura- Low Noise (16V , typ) RMS tion provides noise attenuation for the RF transceiver power supply in the 100Hz to 100kHz range. Simple Logic ON/OFF Controls Other features include separate output enables, low- Low 0.1A Shutdown Current supply current shutdown, output overcurrent, and 2.7V to 5.5V Supply Voltage Range overtemperature protection. The MAX8896 is available in a 16-bump, 2mm x 2mm UCSP package (0.7mm Thermal Shutdown max height). 2mm x 2mm UCSP Package (4 x 4 Grid) Applications Ordering Information WCDMA/NCDMA Cellular Handsets LDO Smartphones PART PIN-PACKAGE VOLTAGE MAX8896EREE+T 16 UCSP (0.5mm pitch) 2.80V Note: Device operates over the -40C to +85C temperature range. +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. UCSP is a trademark of Maxim Integrated Products, Inc. Pin Configurations appear at end of data sheet. Maxim Integrated Products 1 For information on other Maxim products, visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEDual PWM Step-Down Converter in a 2mm x 2mm Package for WCDMA PA and RF Power ABSOLUTE MAXIMUM RATINGS V , IN1, IN2, PAEN, RFEN1, RFEN2, PAOUT, OUT2, LDO Short Circuit to PGND1, CC REFIN, OUT2, REFBP to AGND .........................-0.3V to +6.0V PGND2 ....................................................................Continuous PAOUT to AGND........................................-0.3V to (V + 0.3V) Continuous Power Dissipation (T = +70C) IN1 A LDO to AGND .........................................-0.3V to (V + 0.3V) 16-Bump UCSP (derate 12.5mW/C above +70C) ............1W OUT2 IN1, IN2 to V ......................................................-0.3V to +0.3V Junction-to-Ambient Thermal Resistance ( ) (Note 1)...96C/W CC JA IN1 to IN2 ..............................................................-0.3V to +0.3V Junction Temperature......................................................+150C PGND1, PGND2 to AGND.....................................-0.3V to +0.3V Storage Temperature Range .............................-65C to +150C LX1 Current .......................................................................1A Bump Temperature (soldering, reflow) ...........................+260C RMS LX2 Current .......................................................................1A RMS IN1 and PAOUT Current....................................................1A RMS Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four- layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. 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 (V = V = V = V = V = V = 3.6V, V = 0.72V, T = -40C to +85C, typical values are at T = +25C, CC IN1 IN2 PAEN RFEN1 RFEN2 REFIN A A unless otherwise noted.) (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS INPUT SUPPLY Input Voltage V , V V 2.7 5.5 V CC IN1, IN2 Input Undervoltage Threshold V rising, 180mV typical hysteresis 2.52 2.63 2.70 V CC T = +25C 0.1 4 A Shutdown Supply Current V = V = V = 0 A P AEN R FE N 1 R FE N 2 T = +85C 0.1 A LOGIC CONTROL PAEN, RFEN1, RFEN2 Logic 2.7V V 5.5V 1.3 V CC Input High Voltage PAEN, RFEN1, RFEN2 Logic 2.7V V 5.5V 0.4 V CC Input Low Voltage PAEN, RFEN1, RFEN2 Internal 400 800 1600 k Pulldown Resistor T = +25C 0.01 1 PAEN, RFEN1, RFEN2 Logic A V = 0 A IL Input Current T = +85C 0.1 A REFBP REFBP Output Voltage 0A IREFBP 1A 1.237 1.250 1.263 V THERMAL PROTECTION Thermal Shutdown T rising, 20C typical hysteresis +160 C A OUT1 VRFEN1 = VRFEN2 = 0V, IPA = 0A, Quiescent Supply Current 155 A no switching p-channel MOSFET switch, I = -200mA 0.16 0.40 LX1 On-Resistance n-channel MOSFET rectifier, I = 500mA 0.17 0.40 LX1 Load Regulation R is the inductor resistance R /2 V/A L L T = +25C 0.1 5 A LX1 Leakage Current V = 5.5V, V = 0V A IN1 LX1 T = +85C 1 A 2 MAX8896