WM0838

WM0834, WM0838 Production Data Sept 1996 Rev 2.0 8-Bit ADCs with Serial Interface and Configurable Input Multiplexer Description WM0834 and WM0838 are 8-bit analogue to digital converters (ADC) with configurable 4-input and 8-input multiplexers respectively and a serial I/O interface. Assignment of the multiplexer inputs is configured before each conversion via the serial data input to give single-ended or differential operation for the selected inputs. A mixture of input configurations can be used in the same application. WM0838 also has a pseudo-differential configuration where all 8 inputs can be refered to a common input at an arbitrary voltage. Serial communcation with WM0834/8 is via Data In (DI) and Data Out (DO) wires under the control of clock and chip select inputs. A high output at the SARS pin indicates when the conversion is in progress. To initiate a conversion chip enable is held low and data is input to DI on the rising edge of the clock, comprising, a start bit, and bits to set up the input configuration and polarity. After a half clock cycle delay conversion results appear at DO on the falling edge of the clock, MSB first, concurrently with A-D conversion. This is followed by the results LSB first, indicated by the falling edge of SARS. WM0838 has a shift enable (SE) input used to control the LSB first output on DO. WM0834/8 operate on 5V and 3.3V supply voltages and are available in small outline and DIP packages for commercial (0 to 70OC) and industrial (...