低功耗低温漂高PSR带隙基准电压源的设计

Design of a bandgap voltage reference with low power, low TC and high PSR

在专用医学微弱信号放大电路中，需要非常精准的电压源，为此，提出了一种新型的带隙基准电压源，采用低温补偿和高温补偿相结合的温度补偿方式，输出带隙基准电压为1．109v，在-40～125℃范围内的温度系数为0．445。0．604ppm／℃。同时采用了预稳压器来提高电路的PSR（电源抑制），使得PSR在10Hz时为-127．5dB，在100kHz时达到-63dB。文中设计的电路静态电流只有10μA，消耗的功耗在36pW左右。该带隙基准电路还有不随工艺变化的特点，工艺差别使输出电压最大产生61．5μV的变化。

A new method to compensate the TC （Temperature Coefficient） of the bandgap voltage reference circuit is proposed in this paper, it contains the TC compensation both in the low and high range of temperature. The circuit achieves a TC of 0.445ppm/℃-0.604ppm/℃ over the temperature range of -40℃ to 125 ℃ with 1,109 0 V output reference voltage. In order to enhance the PSR over a broad frequency range, this paper also presents a pre-regulator which can boost the PSR of the circuit to -127.5 dB at 10Hz and -63 dB at 100 kHz. In addition, the static current of the proposed bandgap reference circuit is only 10 μA, and the power thus consumed is about 36 μW. The output voltage of the circuit is affected by the process variations slightly： the corner variations only yield a 60 μV output voltage difference. All the advantages above make this bandgap voltage reference circuit can be used in medical weak signal amplifying.