Evaluation board for the AD7709, which is a Low Voltage, Low Power, 16-Bit, Sigma Delta ADC. The AD7709 is a complete analog front end for low frequency measurement applications. The device can accept low level input signals directly from a transducer and produce a serial digital output. It employs a sigma-delta conversion technique to realize up to 16 bits of no missing codes performance. The selected input signal is applied to a proprietary programmable gain front end based around an analog modulator. The modulator output is processed by an on-chip digital filter. The first notch of this digital filter can be programmed via an on-chip control register allowing adjustment of the filter cutoff and output update rate. The device also contains three switchable, ratioed current sources. Full data on the AD7709 is available in the AD7709 datasheet (available on the AD7709 Product Page) and should be consulted in conjunction with this Technical Note when using the evaluation board.
The analog DAC output, and ADC analog input can be accessed through SMA connectors or pin headers on the evaluation board. The jumper programmable interface configurations allow several different circuit options to suit different testing methods. An on-board digital loopback feature allows the ADC and DAC to be tested simultaneously with the use of a signal source and spectrum analyzer.