MAX4473 低成本、低电压、PA功率控制放大器，用于GS

MAX4473 低成本、低电压、PA功率控制放大器，用于GSM应用

MAX4473 概述

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-multiple-access (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.

The MAX4473 operates from a single 2.7V to 6.5V supply and typically draws 1.2mA of supply current. The error amplifier has a common-mode range that extends from 1V to V_CC. The power control input and error amplifier outputs swing rail-to-rail. A low-power shutdown mode reduces supply current to less than 1µA and activates an on-board active pull-down at the error amplifier output. Fast enable/disable times of 0.9µs reduce average power consumption without compromising dynamic performance. The MAX4473 is available in a space-saving 8-pin µMAX® package.

MAX4473 pdf datasheet (PA Power Control)

MAX4473 关键特性

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 V_CC Current Sense Input Common-Mode Voltage Range

No Phase-Reversal for Common-Mode Voltage from 0 to V_CC

External Current Sensing and Gain Setting Resistors Maximize Flexibility

Available in a Space-Saving 8-Pin µMAX Package

MAX4473 应用/使用

 无绳电话
 GSM蜂窝电话
 高频伺服环路
 精密电流控制

典型工作电路

用于控制放大器低成本功率

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