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MCP651 INPUT OFFSET

EVALUATION BOARD

USER’S GUIDE

©

 2009 Microchip Technology Inc.

DS51834A-page 1

Preface

INTRODUCTION

This chapter contains general information that will be useful to know before using the 
MCP651 Input Offset Evaluation Board. Items discussed in this chapter include:
• Document Layout
• Conventions Used in this Guide
• Recommended Reading
• The Microchip Web Site
• Customer Support
• Document Revision History

DOCUMENT LAYOUT

This document describes how to use the MCP651 Input Offset Evaluation Board. The 
manual layout is as follows:

Chapter 1. “Product Overview”

 - Important information about the MCP651 Input 

Offset Evaluation Board.

Chapter 2. “Installation and Operation”

 – Covers the initial set-up of the 

MCP651 Input Offset Evaluation Board. It lists the required tools, shows how to 
set up the board and how to connect lab equipment. It then demonstrates how to 
use this board.

Chapter 3. “Possible Modifications”

 – Shows how to modify the board for other 

single Microchip op amps in SOIC-8, PDIP-8 and other packages.

Appendix A. “Schematics and Layouts”

 – Shows the schematic and board 

layouts for the MCP651 Input Offset Evaluation Board.

Appendix B. “Bill Of Materials (BOM)”

 – Lists the parts used to populate the 

MCP651 Input Offset Evaluation Board. Also lists loose parts shipped with the 
board in an ESD bag, alternate components and components not populated.

NOTICE TO CUSTOMERS

All documentation becomes dated, and this manual is no exception. Microchip tools and 
documentation are constantly evolving to meet customer needs, so some actual dialogs 
and/or tool descriptions may differ from those in this document. Please refer to our web site 
(www.microchip.com) to obtain the latest documentation available.

Documents are identified with a “DS” number. This number is located on the bottom of each 
page, in front of the page number. The numbering convention for the DS number is 
“DSXXXXXA”, where “XXXXX” is the document number and “A” is the revision level of the 
document.

For the most up-to-date information on development tools, see the MPLAB

®

 IDE on-line help. 

Select the Help menu, and then Topics to open a list of available on-line help files.

Содержание MCP651

Страница 1: ...2009 Microchip Technology Inc DS51834A MCP651 Input Offset Evaluation Board User s Guide...

Страница 2: ...f Microchip Technology Incorporated in the U S A All other trademarks mentioned herein are property of their respective companies 2009 Microchip Technology Incorporated Printed in the U S A All Rights...

Страница 3: ...2 2 Required Tools 11 2 3 Configuring the Lab Equipment and PCB 12 2 4 Operating Conditions 14 2 5 Converting to Other Parameters 15 2 6 Settling Time Noise and Sampling Rate 17 Chapter 3 Possible Mod...

Страница 4: ...et Evaluation Board User s Guide DS51834A page iv 2009 Microchip Technology Inc Appendix B Bill Of Materials BOM B 1 MCP651 Input Offset Evaluation Board BOM 31 B 2 Adaptor Board BOM 33 Worldwide Sale...

Страница 5: ...icrochip op amps in SOIC 8 PDIP 8 and other packages Appendix A Schematics and Layouts Shows the schematic and board layouts for the MCP651 Input Offset Evaluation Board Appendix B Bill Of Materials B...

Страница 6: ...e Bold characters A dialog button Click OK A tab Click the Power tab N Rnnnn A number in verilog format where N is the total number of digits R is the radix and n is a digit 4 b0010 2 hF1 Text in angl...

Страница 7: ...f the SOIC8EV Evaluation Board THE MICROCHIP WEB SITE Microchip provides online support via our web site at www microchip com This web site is used as a means to make files and information easily avai...

Страница 8: ...MCP651 Input Offset Evaluation Board User s Guide DS51834A page 4 2009 Microchip Technology Inc DOCUMENT REVISION HISTORY Revision A May 2009 Initial Release of this Document...

Страница 9: ...uation Board is described by the following Assembly 102 00258 R2 Order MCP651EV VOS Name MCP651 Input Offset Evaluation Board Items discussed in this chapter include Kit Contents Intended Use Descript...

Страница 10: ...oltages on this board Then there is a discussion of the circuitry that controls the DUT s output voltage VOUTX and amplifies its total input offset voltage VOST Finally other portions of the circuit a...

Страница 11: ...VCMX 0V R3 R4 Integrator 1 GINT INT s GM VM VDDI VSSI 1 GINT C2 2 5V 2 5V 2 5V 2 5V VCOX 1 2 5V 2 5V R78 Lowpass Filter Complete Schematic Components Simplified Schematic Component Conversion Equation...

Страница 12: ...the I part of the PI controller Resistor R56 injects the integrator s output at the DUT s input through resistors R4 and R3 it minimizes the error at VOUTX A proportional term the P part of the PI co...

Страница 13: ...LX The RCAL potentiometer POT or R43 with the resistors R42 and R43 sets VCALX The values chosen allow the POT to cover the specified VCALX range and a little more Connecting a voltmeter to VCALX make...

Страница 14: ...time after CAL CS goes low FIGURE 1 4 CAL Switch and De glitching Circuitry 1 4 5 Bias Inputs for Other Op Amps The other op amps U2 U3 and U4 are run on dual power supplies centered on ground The des...

Страница 15: ...lculating DUT Parameters Settling Time Noise and Sampling Rate 2 2 REQUIRED TOOLS 1 or 2 Lab Power Supplies with two tracking outputs One for 2 5V GND 2 5V The other for VDDX GND VSSX adjustable up to...

Страница 16: ...Figure 2 1 signify the following 1 Gain Setting Switch top position 1 a To the right ON for low gain GM 201 V V b To the left for high gain GM 1998 V V 2 Voltmeter to measure VM a Gives amplified offs...

Страница 17: ...connect to an external lab power supply it is best but not necessary to set RCAL to mid supply 10 Power Supply for VDDX a Minimum of 0 3V for VCMX at 0 3V above positive rail b Maximum of about VSSX D...

Страница 18: ...AL or R43 adjusts VCALX This voltage is where the DUT s common mode input voltage set during a calibration event initiated by pushing S1 Adjusting this POT does not have an effect on the circuit s beh...

Страница 19: ...Specified Input Offset Voltage VOS Input offset at the specified bias point DC Common Mode Rejection Ratio CMRR VCM VOS DC Power Supply Rejection Ratio PSRR VDD VSS VOS DC Open loop Gain AOL VOUT VOS...

Страница 20: ...and PSRR 0 30 4 VM2 CMRR 4 20 VM3 CMRR 0 20 1 83 VM4 AOL 5 30 VM5 AOL 2 5 1 25 0 83 VM6 VOS and PSRR 0 30 VM7 CMRR 1 20 VM8 CMRR 0 20 0 83 VM9 AOL 2 30 VM10 AOL 40 5 5 2 75 1 83 VM11 VOS at temperatur...

Страница 21: ...ver time The standard deviation of this 1 f wander can be estimated to be roughly 5 VP P for a time period of 1 second 34 VP P for a time period of 10 years Averaging several measurements together wil...

Страница 22: ...MCP651 Input Offset Evaluation Board User s Guide DS51834A page 18 2009 Microchip Technology Inc NOTES...

Страница 23: ...Offset Voltage In order to keep op amps U3 and U4 operating normally the DUT s VOS must be EQUATION 3 1 More accurate op amps need higher gain for good resolution Table 3 1 shows what VOS specs can be...

Страница 24: ...e U2 or U3 The maximum DUT VOH and VOL values supported relative to VCM are EQUATION 3 2 Rail to rail output op amps on a single supply voltage must be less than 7 5V 3 2 3 Gain Bandwidth Product Ther...

Страница 25: ...e input pins but they are not necessary to this board s operation FIGURE 3 1 MCP651 Pinout Op Amps with No Connection NC at pins 1 5 and 8 will operate properly on the MCP651 Input Offset Evaluation B...

Страница 26: ...stalled FIGURE 3 3 PCB with SOIC 8 Part Removed and DIP 8 IC Socket Installed The socket may not work well in two cases solder directly to the PCB instead Very fast op amps i e GBWP 100 MHz Very accur...

Страница 27: ...ge and Connector Headers Soldered to Adaptor PCB FIGURE 3 5 Adaptor Board Connected to the MCP651 Input Offset Evaluation Board Note 1 Build the adaptor board in the following sequence Insert the inte...

Страница 28: ...MCP651 Input Offset Evaluation Board User s Guide DS51834A page 24 2009 Microchip Technology Inc NOTES...

Страница 29: ...f starting an auto calibration cycle in the DUT Switch S2 makes it so the amplifier U4 can have two different gains providing a tradeoff between accuracy and range A 4 Board Combination of the Top Sil...

Страница 30: ...MCP651 Input Offset Evaluation Board User s Guide DS51834A page 26 2009 Microchip Technology Inc A 3 BOARD SCHEMATIC M...

Страница 31: ...Schematics and Layouts 2009 Microchip Technology Inc DS51834A page 27 A 4 BOARD COMBINATION OF THE TOP SILK SCREEN TOP SOLDER MASK AND TOP METAL LAYERS...

Страница 32: ...MCP651 Input Offset Evaluation Board User s Guide DS51834A page 28 2009 Microchip Technology Inc A 5 BOARD TOP SILK SCREEN...

Страница 33: ...Schematics and Layouts 2009 Microchip Technology Inc DS51834A page 29 A 6 BOARD TOP SOLDER MASK AND TOP METAL LAYER...

Страница 34: ...MCP651 Input Offset Evaluation Board User s Guide DS51834A page 30 2009 Microchip Technology Inc A 7 BOARD BOTTOM METAL LAYER...

Страница 35: ...0W Susumu Co Ltd RG1608P 512 B T5 1 R4 10 0 k 0603 SMD 0 1 25 ppm C 1 10W Susumu Co Ltd RG1608P 103 B T5 1 R24 15 0 k 0603 SMD 0 1 25 ppm C 1 10W Susumu Co Ltd RG1608P 153 B T5 1 R26 86 6 k 0603 SMD 0...

Страница 36: ...crochip Technology Inc MCP6XXX Note 1 0 U1 DIP 8 IC Socket Tyco Electronics 2 641260 1 0 for PCB mounting Stand off Hex 0 500 4 40 Thread Nylon 0 285 max O D Keystone Electronics 1902C 0 for PCB mount...

Страница 37: ...rer Part Number 1 8 Pin SOIC MSOP TSSOP DIP Evaluation Board Microchip Technology Inc SOIC8EV 2 Board to Board Connector Low Profile Header 4 Positions 0 100 in Gold Plated Samtec Inc BBL 104 G F 2 10...

Страница 38: ...ng Tel 86 24 2334 2829 Fax 86 24 2334 2393 China Shenzhen Tel 86 755 8203 2660 Fax 86 755 8203 1760 China Wuhan Tel 86 27 5980 5300 Fax 86 27 5980 5118 China Xiamen Tel 86 592 2388138 Fax 86 592 23881...

Страница 39: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Microchip MCP651EV VOS...

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