一种基于控制PTAT电流的温度系数可调带隙基准源

设计了一种温度系数可调的带隙基准源,利用控制PTAT电流的大小产生具有不同温度系数的基准电压,仅采用两个双极型晶体管,具有较好的电源噪声抑制特性。与传统方法相比,简化了电路结构,减小了占用芯片面积,改善了版图设计的对称性。该电路在更宽的调节范围内,通过4位控制信号可实现16级的温度系数调节,同时通过设计专门电路提高了电源噪声抑制比。采用0.35μm CMOS工艺实现了该带隙基准源。仿真结果表明,基准电压的温度系数可在-1.76~+1.84 mV/℃范围内进行调节,低频时基准电压的PSRR达到-110 dB。

Bandgap Reference with Adjustable Temperature Coefficient Based on Controlling PTAT Current

A bandgap reference(BGR) with adjustable temperature coefficient was designed.By controlling PTAT current, the temperature coefficient of reference voltage can be adjus-ted from positive to negative. Compared to traditional method, a two-bipolar transistor structure is adopted which could reduce the circuit area in chip and improve the layout sym-metry. Furthermore, an OPAMP circuit was designed to improve the PSRR. The reference voltage could be adjusted in a wider adjustment with 16 levels. Implemented with 0. 35 μm CMOS process, the Hspice simulation results showed that the temperature coefficient can be adjusted from-1.76 mV/℃ to +1.84 mV/℃ and the PSRR of the reference voltage rea-ches -110 dB at low frequency.