AD7938 / AD7939 / AD7938-6 EVALUATION TOOLS

Introduction

The AD7938/AD7939/AD7938-6 are high speed, 12-bit and 10-bit, low power, successive-approximation ADCs. The parts operate from a single 2.7 V to 5.25 V power supply and feature throughput rates up to 1.5 MSPS.

The EVAL-AD7938CB, EVAL-AD7939CB and EVAL-AD7938-6CB can be used to evaluate the AD7938, AD7939 and AD7938-6 respectively. Accompanying each evaluation kit is the AD7938/39/38-6CB evaluation board and a CD-ROM containing a Technical Note, the datasheet and a description for the Evaluation Board Controller. The Technical Note describes the evaluation board for the AD7938/39/38-6. Full details on the AD7938/39/38-6 are also available in the AD7938/AD7939 and the AD7938-6 datasheets (which can be downloaded from the AD7938, AD7939 or AD7938-6 Product Pages) and this should be consulted in conjunction with this Technical Note when using the Evaluation Board.

On-board components include an AD780, which is a pin programmable +2.5 V or +3 V ultra high precision bandgap reference, one AD713 quad op-amp, one AD8022 dual op-amp, six AD8021 single op-amps, two AD8138 differential amplifiers and a P174FCT digital buffer.

Interfacing to this board is through a 96-Way connector. This 96-Way connector is compatible with the evaluation board controller (EVAL-CONTROL BRD2), which is also available from Analog Devices. External sockets are provided for a number of signals including the V_REF input, the analog inputs and the digital inputs and outputs. The evaluation board controller is powered from a 12 V AC transformer. Suitable transformers are available from Analog Devices as an accessory under the following part numbers:

Software

Included in the AD7938/39/38-6CB evaluation board package is software for controlling and evaluating the performance of the AD7938, AD7939 and AD7938-6 when it is operated with the evaluation board controller. The EVAL- AD7938/39/38-6CB Demonstration/Evaluation Software runs under Windows 95, 98, 2000, XP and NT. The user interface on the PC is via a dedicated program written especially for the EVAL-AD7938CB, EVAL-AD7939CB and EVAL-AD7938-6CB.