7.4.2 AVDD Diagnostics and Fail-Safe Output

In the case of a missing high-side supply voltage AVDD, the output of a ΔΣ modulator is not defined and can cause a system malfunction. In systems with high safety requirements, this behavior is not acceptable. As shown in Figure 49, the AMC1336 implements an AVDD diagnostics and fail-safe output function that ensures that the output DOUT of the device offers a steady-state bitstream of logic 0's in case of a missing AVDD. Sample at least 128 CLKIN cycles in order to distinguish a missing AVDD condition from an input underrange condition.

Figure 49. Fail-Safe Output of the AMC1336