Datasheet

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2 EVM Overview
2.1 Features
3 Introduction
4 Analog Interface
EVM Overview
Data Sheets: Literature Number:
ADS8322 SBAS215
THS4031 SLOS224
SN74AHC138 SCLS258
SN74AHC245 SCLS230
SN74AHC541 SCLS261
• Full-featured evaluation board for the ADS8322 16-bit, 500-kHz, single-channel, parallel interface
analog-to-digital converter
• Onboard signal conditioning
• Input and output digital buffers
• Onboard decoding for stacking multiple EVMs
The ADS8322EVM is a single-channel, analog-to-digital converter evaluation board (EVM) based on the
ADS8322 16-bit, 500-kHz, parallel interface analog-to-digital converter (ADC). Typical power dissipation is
85 mW at a 500-kHz throughput rate and 5-V supply. The device uses a parallel interface.
The EVM incorporates an operational amplifier configured as buffer to ensure a low-noise input to the
ADC. This EVM also buffers all the digital input and output signals, effectively isolating the converter from
the parallel bus.
The ADS8322EVM Revision B has been redesigned to include a power connector and to allow for sharing
the parallel bus with another EVM. The parallel interface is therefore significantly changed from
ADS8322EVM Revision A.
The full-scale analog input range for the analog-to-digital (A/D) converter is from 0 V up to twice the
reference voltage. If a 2.5-V reference is used, the input range is from 0 V up to 5 V. Connector J1 is the
analog connector. The singled-ended signal for the noninverting pin of the converter can be applied to
connector J1 pin 2. A amplifier, U5, is located between this pin and the ADS8322 input pin 26 to buffer the
signal. The inverting input pin of the converter is shorted to ground via C41. The buffer circuit for the
inverting input is not populated. It needs to be populated if the user desires to apply a signal to it. The
inverting input has an range of 0 V up to 500 mV.
See Table 1 for analog connector pinout.
Table 1. Analog Input Connector
Description Signal Name Connector.Pin# Signal Name Description
Inverting input (–) J1.1 J1.2 (+) Noninverting input
Reserved N/A J1.3 J1.4 N/A Reserved
Reserved N/A J1.5 J1.6 N/A Reserved
Reserved N/A J1.7 J1.8 N/A Reserved
Pin tied to ground AGND J1.9 J1.10 N/A Reserved
ADS8322EVM 2 SLAU086A – July 2002 – Revised December 2004