Test generation and concurrent error detection in current-mode A/D converters

Analog MOS circuits are becoming increasingly sophisticated in terms of checking and correcting themselves. Self-correcting, self-compensating, or self-calibrating techniques has been employed in analog-to-digital (A/D) converters to eliminate errors caused by offset and low frequency noise and cancel the error effect. For real-time applications, however, it is rather difficult to achieve validation of the converted data in the presence of faulty switching element(s). In this paper, fault behaviors and test generation of a current-mode A/D converter are addressed. Results show that the converter achieves full testability with two test currents. In addition, an A/D converter with concurrent error detection capability is proposed. The converter detects all transient faults