EVM Overview
3
SBAU194B – August 2011 – Revised September 2017
Copyright © 2011–2017, Texas Instruments Incorporated
ADS794xEVM and ADS794xEVM-PDK
1
EVM Overview
1.1
Features
ADS794xEVM Features:
•
Contains all support circuitry needed for the ADS7946/ADS7945 (ADS794x)
•
5-V, 3.3-V, and 1.8-V logic compatible with 16-bit, 40-MHz SPI™ serial interface
•
Simple channel selection with a single 16-bit word command
•
Serial interface header for easy connection to TI DSP-based communication systems
•
Compatible with the TI Modular EVM System
•
Voltage reference options: onboard
(4.096-V) reference or external reference
•
Voltage reference buffering with
•
Onboard
(200-MHz BW, 1-mA quiescent current) ADC input drivers
•
Jumper-selectable bipolar (–V
REF
/2 to +V
REF
/2) or unipolar (0 V to V
REF
) input range
ADS794xEVM-PDK Features:
•
Easy-to-use evaluation software for Microsoft Windows XP
®
operating system PCs
•
Data collection to text files
•
Built-in analysis tools including scope, FFT, and histogram displays
•
Complete control of board settings
•
Easily expandable with new analysis plug-in tools from Texas Instruments
The ADS794xEVM-PDK is available for use with a computer. This kit combines the ADS794xEVM board
with the DSP-based MMB0 motherboard, and includes ADCPro™ software for evaluation.
The MMB0 motherboard allows the ADS794xEVM to be connected to the computer via an available USB
port. This manual shows how to use the MMB0 as part of the ADS794xEVM-PDK, but does not provide
technical details about the MMB0 itself.
ADCPro is a program for collecting, recording, and analyzing data from ADC evaluation boards. It is based
on a number of plug-in programs, so it can be expanded easily with new test and data collection plug-ins.
The ADS794xEVM-PDK is controlled by a plug-in running in ADCPro. For more information about
ADCPro, see the
ADCPro™ Analog-to-Digital Converter Evaluation Software User's Guide
(literature
number
), available for download from the TI web site.
This manual covers the operation of both the ADS794xEVM and the ADS794xEVM-PDK. Throughout this
document, the abbreviation
EVM
and the term
evaluation module
are synonymous with the ADS794xEVM.
Operation of the EVM and kit for both the ADS7946 and the ADS7945 devices is identical, unless
otherwise noted.
1.2
Introduction
The ADS794xEVM is an evaluation module built to the TI Modular EVM System specifications. It can be
connected to any modular EVM system interface card.
The ADS794xEVM is available as a stand-alone printed circuit board (PCB) or as part of the
ADS794xEVM-PDK, which includes an MMB0 motherboard and software. As a stand-alone PCB, the
ADS794xEVM is useful for prototyping designs and firmware because it offers circuitry that meets the
product data sheet specifications of either the ADS7946 or ADS7945 devices.
The ADS7945 and ADS7946 are 14-bit, 2-MSPS ADCs with fully differential and pseudo-differential
unipolar inputs, respectively. These devices operate at a 2-MSPS sample rate with a 16-clock SPI data
frame that features both outstanding dc and excellent dynamic performance. These devices also include a
two-channel input multiplexer and a low-power SAR ADC with an inherent sample-and-hold (S/H) input
stage. During normal operation at 2 MSPS, the ADS794x dissipates a mere 11.6 mW.
Note that the ADS794xEVM has no microprocessor and cannot run software. Therefore, some type of
interface is required to connect the ADS794xEVM to a computer. In the ADS794xEVM-PDK kit, the MMB0
motherboard serves as the interface between the computer and the ADS794xEVM board.