一种内嵌EEPROM的双电源数字电位计设计

摘要

The paper introduces a design of dual supply digitally controlled potentiometer based on EEPROM. The EEPROM cells were controlled through two wire I2C bus,can adjust the digitally controlled potentiometer resistor or voltage output. The potentiometer has dual supply and 256 resistor taps. The potentiometer has non-volatile EEPROM storage of wiper position, so when the device is powered down suddendly, the last value stored in the non-volatile EEPROM memory. When power is restored, the contents of the non-volatile EEPROM memory are recalled and loaded into the corresponding latchs to set wipers to their initial positions. The circuit uses 0.18 μm EEPROM technology, and layout is 6.76 mm2. Hsim is used for simulating. The simulate and test results show that: the integral non-linearity of the circuit is less than ± 1 LSB, the diffenrential non-linearity is less than ±0.5 LSB, the temperature coefficient of output resistors is less than ±100×10-6/℃,the power-on delay is less than 5 ms. This digitally controlled potentiometer can be used in wide variety of applications including control, parameter adjustments, and signal processing.%设计了一种基于嵌入式EEPROM工艺的双电源数字电位计。通过两线的I2C总线来控制电路内部EEPROM单元，调节数字电位计的输出电阻或电压。电路采用正负电源供电，同时集成了两路256个抽头可变电位计输出。由于内部集成了EEPROM单元，当电路突然掉电后依然保存抽头设置信息，重新上电后，自动恢复到掉电前电阻抽头的设定位置。该电路采用SMIC 0.18μm EEPROM工艺设计，版图面积为6.76 mm2，采用Hsim对整个电路进行仿真。仿真和测试结果表明，该电位计电路的整体非线性小于±1 LSB，级间非线性小于±0.5 LSB，输出电阻温度系数小于±100×10-6/℃， EEPROM上电恢复时间小于5 ms，可广泛应用于控制系统、参数调整和信号处理领域。