MAXIM MAX4473EUA+T

The MAX4473 PA power control IC is intended for closed-loop bias control of GSM power amplifiers. The device facilitates accurate control of the current delivered to the power amplifier (PA) through a control voltage. The error amplifier senses the voltage drop across an external current-sense resistor placed between the supply and the PA. The output of the error amplifier adjusts the PA gain until the current is proportional to the power control voltage applied to the MAX4473. This unique topology is useful in time-division-multipleaccess (TDMA) systems, such as GSM, where accurate transmit burst shaping and power control is required. User-selectable current sensing and gain setting resistors maximize flexibility.

• Optimized for GSM Timing Requirements
• 2.7V to 6.5V Single-Supply Operation
• 1.2mA Supply Current
• ≤1μA Supply Current in Shutdown Mode
• Guaranteed 1.5μs Enable/Disable Times
• Active Output Pull-Down in Shutdown Mode
• Rail-to-Rail Error Amplifier Output
• Rail-to-Rail Power Control Input
• Output Drive Capability—500Ω and 300pF Loads
• 1V to VCC Current Sense Input Common-Mode Voltage Range
• No Phase-Reversal for Common-Mode Voltage from 0 to VCC
• External Current Sensing and Gain Setting Resistors Maximize Flexibility
• Available in a Space-Saving 8-Pin µMAX

• GSM Cellular Phones
• Cordless Phones
• Precision Current Control
• High-Frequency Servo Loops