TIDA-00548 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 (PLCs). 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 help to develop systems according to IEC 61508 SIL 3.
Features
- Two channel 4- to 20-mA current measurement for redundancy with full-scale error less than ±0.01%
- Two ADC references (external and internal)
- Utilizes ADC built-in features such as test DAC, secondary ADC, analog signal level alarm, SPI CRC, 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