4-20mA Analog Input Module Reference Design for Safety Applications

1 января 2018

The TIDA-00548 design is an isolated dual-channel 4- to 20-mA analog input reference design, which can be used as a sub-part for functional safety programmable logic controllers (PLC). This reference design delivers digitized input values using a 32-bit high-performance analog-to-digital converter (ADC). The RM4x dual-core ARM® Cortex®-R4 based CPU with lockstep technology and built-in self-tests (BIST) compares the converted values of up to nine selectable analog input signal chain paths. The dual input approach with two separate burden resistors allows redundant measurement of either a single 4- to 20-mA loop or two independent loops. Hercules™ RM ARM Cortex-R based MCUs for functional safety applications (part of the SafeTI designs packages) help to develop systems according to IEC 61508 SIL 3.

Особенности

Two channel 4- to 20-mA current measurement for redundancy with full-scale error less than ±0.01% Two ADC references (external, internal) Utilizes ADC built-in features such as test DAC, secondary ADC, analog signal level alarm, SPI CRC and timeout, and more Hercules RM ARM Cortex-R based MCU (for development of IEV 61508 functional safety applications) Isolator shutdown upon failure provides reliable notification to backend All integrated circuits: MTBF greater 4·10^8