Maxim MAX2253x系列四路12位隔离ADC解决方案

Maxim公司的MAX22530-MAX22532是电流隔离四路复用12位模数转换器(ADC),属于MAXSafe™系列产品线.集成的隔离DC/DC转换器给所有的场侧电路供电,这就使得没有输入信号时也能进行到场侧诊断. MAX22530-MAX22532能连续数字化隔离层场侧的输入电压,跨过隔离层发送数据到器件的逻辑侧,那里的输入电压幅度和可编程阈值可相比拟.12位ADC核取样速率每路为20ksps.ADC数据可通过SPI接口直接得到或进行滤波.对于SSOP封装可经受住3.5kVRMS隔离60秒(VISO),对于宽SOIC封装可经受住5kVRMS隔离60秒(VISO).由于高集成度,可降低BOM和PCB板空间,集成的DC/DC电源可进行场侧电路自供电.器件集成了1.8V基准,精度±1% (典型值),工作温度-40C到+125C.主要用在高压二进制株,变电站自动化,配电系统自动化,过程自动化以及马达控制.本文介绍了MAX2253x系列主要优势和特性,四路隔离ADC框图和功能框图,应用电路,评估板MAX2253x EVK主要特性,以及评估板MAX22530 EVK和评估板MAX22531 EVK电路图,材料清单和PCB设计图.

The MAX22530–MAX22532 are galvanically isolated, 4-channel, multiplexed, 12-bit, analog-to-digital converters (ADC) in the MAXSafe™ family product line. An integrated, isolated, DC-DC converter powers all field-side circuitry, and this allows field-side diagnostics even when no input signal is present.

The MAX22530–MAX22532 family continually digitizes the input voltage on the field-side of an isolation barrier and transmits the data across the isolation barrier to the logic-side of the devices where the magnitude of the input voltage is compared to programmable thresholds. The 12-bit ADC core has a sample rate of 20ksps (typ) per-channel. ADC data is available through the SPI interface either directly or filtered. Filtering averages the most recent 4 readings depending on the setting.

Each input has a comparator with programmable high and low thresholds, and an interrupt is asserted when any input crosses its programmed level based on the mode setting. The comparator output pin (COUT_) is high when the input voltage is above the upper threshold and low when it is below the lower threshold in digital input m...