AD7739

The AD7739 is a high precision, high throughput analog front end. True 16-bit p-p resolution is achievable with a total conversion time of 250 µs (4 kHz channel switching), making it ideally suited to high resolution multiplexing applications. The part can be configured via a simple digital interface, which allows users to balance the noise performance against data throughput up to 15 kHz.

The analog front end features eight single-ended or four fully differential input channels with unipolar or bipolar 625 mV, 1.25 V, and 2.5 V input ranges. It accepts a common-mode input voltage from 200 mV above AGND to AVDD 300 mV. The differential reference input features "No-Reference" detect capability. The ADC also supports per channel system calibration options.

The digital serial interface can be configured for 3-wire operation and is compatible with microcontrollers and digital signal processors. All interface inputs are Schmitt triggered. The part is specified for operation over the extended industrial temperature range of 40°C to +105°C. Other parts in the AD7739 family are the AD7738, AD7734, and AD7732.

The AD7738 is similar to the AD7739 but has higher speed (8.5 kHz channel switching for 16-bit performance) and higher AIN leakage current. The AD7738 multiplexer output is pinned out externally, allowing the user to implement programmable gain or signal conditioning before being applied to the ADC. The AD7734 analog front end features four single-ended input channels with unipolar or true bipolar input ranges to ±10 V while operating from a single +5 V analog supply.

The AD7734 accepts an analog input overvoltage to ±16.5 V without degrading the performance of the adjacent channels. The AD7732 is similar to the AD7734, but its analog front end features two fully differential input channels.