XRD8794AB View Datasheet(PDF) - Exar Corporation

Part Name

Description

Manufacturer

XRD8794AB

XRD8794AB Application Board

Exar Corporation 

...the analog plus companyTM

XRD8794AB

XRD8794AB

Application Board

March 1996-3

EVALUATION KIT PARTS LIST

This kit contains the following:

 XRD8794AB Application Board

 XRD8794 5V ADC or XRD87L94 3V ADC

 XRD8794AB Application Note

 XRD8794 or XRD87L94 Data Sheet

FEATURES

 Same Printed Circuit Board Design Used in

Production Test Flow

 Easy Evaluation of XRD8794, XRD87L94 & MP8791*

 True 12 Bit Accurate Circuit & Board Layout

 Optimized Support Circuits

 User Friendly / Flexible Interface

INTRODUCTION

The XRD8794AB is a complete printed circuit test board

designed to permit quick and accurate evaluation of

EXAR’s XRD8794 & XRD87L94, 12-bit 2 MSPS

analog-to-digital converters.

The XRD8794AB is the same DUT board used in EXAR’s

production test. This results in a true 12-bit board that

provides a common platform for both our customers and

our engineers. The top of the XRD8794AB is designed as

an applications board and the bottom for interfacing to

EXAR’s in-house testers.

The XRD8794AB can also be used to evaluate the

MP8791 because the products are pin-for-pin

compatible.* This applications board combines a proven

PC Board layout with optimized analog and digital

interface circuitry to satisfy the stringent requirements

needed in evaluating high performance devices of this

type.

The board contains the device being tested (XRD8794),

operational amplifiers for input buffers, latches,

numerous connectors, jumper options, and observation

test points in commonly used locations.

Complete DC and AC performance of the part can be

evaluated by interfacing external laboratory equipment to

the flexible user interface.

* Functional Difference – MP8791 does not high-z digital out-

puts automatically, see section: MP8791 in XRD8794AB

PREVIEW OF COMMON TEST CONFIGURATIONS

The board is set up as a general A/D test circuit where the

references are fixed. Figure 4. shows this default test

circuit. Circuit timing is demonstrated in Figure 7. There

are many other circuit possibilities built into the universal

test board, however, starting with the default circuit is

recommended.

In addition to the default test circuit, two other test

configurations are discussed: the cross plot test and the

external reconstruction DAC test.

Options for analyzing the output results are discussed in

detail below. The most effective of these is the use of a

high speed data acquisition system and FFT software to

compute the performance parameters.

PCB CONSTRUCTION & LAYOUT

(DUAL PURPOSE BOARD)

The XRD8794AB is used as both an applications board

and as a test board at EXAR. The board was designed on

the top as an applications and characterization board.

The bottom was designed to interface to EXAR’s in-house

production testers (with the exception of a few

components that are common to both designs). This

application note focuses on the top side of the board for

laboratory characterization and not production test.

Therefore, there are additional labels and patterns on the

board that are not used or mentioned in this application

note. Figure 1. clarifies which patterns are not used or

discussed in this application note.

Rev. 1.00

E1996

EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 z (510) 668-7000 z FAX (510) 668-7017

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