KAD/MDC/002 2 x 64 channels Multiplexing ADC

2 x 64 channel Pressure Scanner Multiplexing ADC (programmable analog gain, pressure scanner, external temp. compensation) - 2ch at 12.5ksps

The KAD/MDC/002 is designed to interface two multiplexed analog signals such as those from analog pressure scanners. The KAD/MDC/002 has two analog inputs and two constant current RTD inputs for differential voltages/external temperature measurements. In addition to measurement channels, the KAD/MDC/002 provides a 6-bit address bus for an external multiplexer. The KAD/MDC/002 sequentially addresses the 64 channels of an external multiplexer and measures the voltage on the multiplexer's outputs. The interval within all external channels that are addressed is programmable in the range of 5.12 ms to 128 ms.

In a typical operation the multiplexer's address is set to "0000002" at the start of an acquisition cycle. 80 µs later, both multiplexer's outputs are sampled. The address is then incremented to "0000012" and multiplexer outputs are sampled again. After 5.1 2ms the address reads "1111112" and all 128 channels from both inputs have been sampled. Two four-wire constant current RTD inputs are provided to monitor the temperature of the external multiplexer. The constant current excitation for PT100 and PT500 sensors can be programmed to 0.5 mA or 2.5 mA. The external temperature channels are continuously sampled and a running average maintained. These values are used to generate an additional gain and offset for each of 64 external channels per input.