具有寄生电阻消除功能的远端测温芯片

Remote Temperature Measurement Chip with Parasitic Resistance Cancellation Function

设计并流片实现了一款具有寄生电阻消除功能的远端测温芯片。分析了远端测温原理和寄生电阻对测温精度的影响,利用差分结构采集远端三极管产生的温度信号。采用一阶Σ-Δ模数转换器(ADC)将温度信号进行量化,并使用寄生电阻消除技术降低寄生电阻对测温精度的影响。该芯片采用0.18μm BCD工艺设计并流片,测试结果表明,当远端三极管在-40℃下,使用寄生电阻消除技术可以将1.5 kΩ寄生电阻对测温精度的影响降低到0.5℃以内;远端三极管在-40~125℃温度范围内,消除寄生电阻影响后远端测温芯片的3σ误差小于±0.6℃。

A remote temperature measurement chip with parasitic resistance cancellation function was designed and implemented.The principle of remote temperature measurement and the influence of parasitic resistance on the temperature measurement accuracy were analyzed.The differential structure was used to collect the temperature signal generated by the remote transistor.The first-order Σ-Δ analog-to-digital converter(ADC)was used to quantify the temperature signal.Meanwhile the parasitic resis-tance cancellation technology was used to reduce the influence of parasitic resistance on the temperature measurement accuracy.The chip was designed and fabricated by 0.18 μm BCD process.The measurement results show that when the remote transistor is at-40 ℃,the influence of 1.5 kΩ parasitic resis-tance on the temperature measurement accuracy is reduced to less than 0.5 ℃ using the parasitic resis-tance cancellation technology.When the remote transistor is at the temperature range of-40-125 ℃,the 3σ error of the remote temperature measurement chip is less than ±0.6 ℃ after cancelling the influence of parasitic resistance.