一种自动校准的低噪声放大器偏置电路

An Automatically Adjust Bias Circuit for the Low Noise Amplifier

设计了一款用来偏置增强型和耗尽型A类低噪声放大器的电源芯片，通过自动校准外接放大器的栅压使其漏端电流保持恒定。芯片在温度、电源、工艺变化时实现了良好的偏置稳定性，并且避免了这些变化导致的放大器RF性能的退化。测试结果表明，它提供的漏压范围为4～12V；漏电流范围为20～200mA；漏电流随数字电源的变化率为0．79％、随温度的变化率为0．022％；漏电压随温度的变化率为0．07％。芯片内部集成负压电荷泵电路偏置耗尽型放大器，产生-2．45V的电压。芯片使用0．25μmBCD工艺制造，面积为16mm×1．6mm。

A power supply chip was designed which can be used for the bias enhancement and depletion mode low noise amplifier operating in Class-A regime. It can automatically adjust the gate voltage of an external amplifier to achieve constant drain current. The chip achieves excellent bias stability over supply, temperature and process variations, and prevents RF performance degradation due to such variations. Measurement results show that it can provide drain voltages from 4 V to 12 V, drain currents from 20 mA to 200 mA, drain current change over digital voltage is 0.79%, drain current change over temperature is 0. 022%, drain voltage change over temperature is O. 07%. The chip has an integrated negative voltage generator with change pump to drive depletion mode amplifiers, which generated -2.45 V voltage. The chip is implemented in 0.25 μm BCD technology and consumes an area of 1.6 minx 1.6 ram.