MAX4473 19-1448 Rev 4 11/08 Low-Cost, Low-Voltage, PA Power Control Amplifier for GSM Applications General Description Features The MAX4473 PA power control IC is intended for Optimized for GSM Timing Requirements closed-loop bias control of GSM power amplifiers. The 2.7V to 6.5V Single-Supply Operation device facilitates accurate control of the current deliv- ered to the power amplifier (PA) through a control volt- 1.2mA Supply Current age. The error amplifier senses the voltage drop across 1A Supply Current in Shutdown Mode an external current-sense resistor placed between the supply and the PA. The output of the error amplifier Guaranteed 1.5s Enable/Disable Times adjusts the PA gain until the current is proportional to the power control voltage applied to the MAX4473. This Active Output Pull-Down in Shutdown Mode unique topology is useful in time-division-multiple- Rail-to-Rail Error Amplifier Output access (TDMA) systems, such as GSM, where accurate transmit burst shaping and power control is required. Rail-to-Rail Power Control Input User-selectable current sensing and gain setting resis- Output Drive Capability500 and 300pF Loads tors maximize flexibility. The MAX4473 operates from a single 2.7V to 6.5V sup- 1V to V Current Sense Input Common-Mode CC ply and typically draws 1.2mA of supply current. The Voltage Range error amplifier has a common-mode range that extends No Phase-Reversal for Common-Mode Voltage from 1V to V . The power control input and error CC from 0 to V CC amplifier outputs swing rail-to-rail. A low-power shut- down mode reduces supply current to less than 1A External Current Sensing and Gain Setting and activates an on-board active pull-down at the error Resistors Maximize Flexibility amplifier output. Fast enable/disable times of 0.9s Available in a Space-Saving 8-Pin MAX reduce average power consumption without compro- mising dynamic performance. The MAX4473 is avail- Ordering Information able in a space-saving 8-pin MAX package. Applications PART TEMP RANGE PIN-PACKAGE GSM Cellular Phones MAX4473EUA -40C to +85C 8 MAX Cordless Phones MAX4473ESA -40C to +85C 8 SO Precision Current Control Pin Configuration appears at end of data sheet. High-Frequency Servo Loops MAX is a registered trademark of Maxim Integrated Products, Inc. Typical Operating Circuit V CC 0.1F R SENSE RG1 RG2 8 12 V SR1 SR2 4 CC PC OUT 7 I CCPA A3 A1 BUFFER GC V-TO-I 3R ERROR V CC CONVERTER IN AMPLIFIER PA A2 Q1 R MAX4473 3 SHDN GND SR3 RFIN V RG1 5 PC 6 I = CCPA 4 RG3 R RG3 SENSE Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.Low-Cost, Low-Voltage, PA Power Control Amplifier for GSM Applications ABSOLUTE MAXIMUM RATINGS V to GND..............................................................................7V Continuous Power Dissipation (T = +70C) CC A SR1, SR2, SR3, PC, SHDN, 8-Pin MAX (derate 4.10mW/C above +70C) ............330mW OUT to GND ............................................-0.3V to (V + 0.3V) 8-Pin SO (derate 5.88mW/C above +70C).................471mW CC SR1 to SR3......................................................................0 to V Operating Temperature Range ...........................-40C to +85C CC OUT and SR3 Short-Circuit Duration Junction Temperature......................................................+150C to V or GND ........................................................Continuous Storage Temperature Range...........................-65C to +150C CC Current into Any Pin..........................................................50mA Lead Temperature (soldering, 10s) .................................+300C 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 = 2.7V to 6.5V, SHDN > 2.4V, MAX4473 test circuit, RG1 = RG2 = 1k 1%, RG3 = 2.5k 1%, R = 100 1%, CC SENSE R = 10k, C = 300pF, T = T to T , unless otherwise noted. Typical values are at V = 6.0V, V = 1.0V, T = +25C.) (Note 1) L L A MIN MAX CC PC A PARAMETER CONDITIONS MIN TYP MAX UNITS GENERAL Supply Voltage 2.7 6.5 V Supply Current V = 0 1.2 2 mA PC Shutdown Supply Current SHDN < 0.4V, R = 10 0.03 1 A L SHDN Input High Voltage 2.4 V SHDN Input Low Voltage 0.4 V SHDN Input Current SHDN = 0 to V 0.5 A CC ERROR AMPLIFIER 1V < V , V < V 0.5 2 SR1 SR2 CC SR1, SR2 Input Offset Voltage mV 1V < V , V < V at +25C 0.5 1 SR1 SR2 CC SR1, SR2 Input Offset Voltage 10 1V < V , V < V V/C SR1 SR2 CC Drift SR1, SR2 Input Common-Mode Inferred from CMRR test V = GND (Note 2) 1 V V SR2 CC Voltage Range SR1, SR2 Input Bias Current 1V < V , V < V , V = GND, SR3 = unconnected 0.04 1 A SR1 SR2 CC PC SR1, SR2 Input Bias Offset 1V < V , V < V , V = GND, SR3 = unconnected 0.001 0.2 A SR1 SR2 CC PC Current SR1, SR2 Shutdown Leakage SHDN < 0.4V, V = V = V 0.001 0.5 A SR1 SR2 CC Current V = 2.7V 65 85 CC 1V < V , V < V , SR1 SR2 CC Common-Mode Rejection Ratio dB V = GND PC V = 6.5V 75 95 CC Power-Supply Rejection Ratio 2.7V < V < 6.5V, V = GND 80 90 dB CC PC V = 6.5V, 0.3V < V < 6V 80 130 CC OUT R = 10k to V / 2 L CC V = 2.7V , 0.3V < V < 2.4V 80 125 C C OUT Large-Signal Gain dB V = 6.5V , 0.7V < V < 5.5V 80 130 C C OUT R = 500 to V / 2 L CC V = 2.7V , 0.7V < V < 2.2V 80 120 C C OUT 2 MAX4473