DPM7109 12-Bit µP Compatible ADC IC

An analog-to-digital converter (ADC) takes a voltage or current as an analogue input and transforms it to a digital value that a microprocessor can read. ADCs are available at a variety of speeds, with varying interfaces and degrees of precision. Flash, successive approximation, and sigma-delta ADCs are the most prevalent.

A successive approximation converter converts data using a comparator and counting logic. The first stage in the conversion is to determine whether the input voltage exceeds half of the reference value. The output set’s most significant bit (MSB). After subtracting this value from the input, the output is compared to one quarter of the reference voltage. This procedure is repeated until all of the output bits have been set or reset. To execute a conversion, a successive approximation ADC requires as many clock cycles as there are output bits.

These ADCs appear to the CPU as memory locations TTL Voltage-Level Specifications or I/O ports, with no requirement for connecting circuitry. The differential analogue voltage inputs, on the other hand, provide for increased common-mode rejection and offset of the analogue zero input voltage value. In addition, the voltage reference input was changed to allow complete 8-bit resolution encoding of any narrower analogue voltage spread.

Applications

• Operates With Any 8-Bit µP Processors or as a Stand-Alone Device
• Interface to Temp Sensors, Voltage Sources, and also Transducers