Typical channel monitoring circuit diagram

In multi-channel DAC systems, being able to monitor all outputs from a single point is very beneficial for troubleshooting and diagnostic analysis. The circuit described in this article utilizes a single-channel SAR type ADC to implement output channel monitoring of a multi-channel DAC.

The circuit diagram shown below utilizes the internal multiplexer of the 40-channel, 14-bit DACAD5380 so that all 40 output channels can be individually routed to a single output (MON_OUT) pin and then through an external ADC (AD7476) monitor. This approach utilizes far less circuitry than would be required to monitor each channel individually.