MCP6V01 Input Offset Demo Board User’s Guide © 2009 Microchip Technology Inc.
Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature.
MCP6V01 INPUT OFFSET DEMO BOARD USER’S GUIDE Table of Contents Preface ........................................................................................................................... 1 Introduction............................................................................................................ 1 Document Layout .................................................................................................. 1 Conventions Used in this Guide ............................................
MCP6V01 Input Offset Demo Board User’s Guide NOTES: DS51801A-page iv © 2009 Microchip Technology Inc.
MCP6V01 INPUT OFFSET DEMO BOARD USER’S GUIDE Preface 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.
MCP6V01 Input Offset Demo Board User’s Guide CONVENTIONS USED IN THIS GUIDE This manual uses the following documentation conventions: DOCUMENTATION CONVENTIONS Description Arial font: Italic characters Represents Referenced books Emphasized text A window A dialog A menu selection A field name in a window or dialog A menu path MPLAB® IDE User’s Guide ...is the only compiler...
Preface RECOMMENDED READING This user's guide describes how to use MCP6V01 Input Offset Demo Board. Other useful documents are listed below. The following Microchip documents are available and recommended as supplemental reference resources. MCP6V01/2/3 Data Sheet, “300 µA, Auto-Zeroed Op Amps”, DS22058 Gives detailed information on one op amp family that is used on the MCP6V01 Input Offset Demo Board.
MCP6V01 Input Offset Demo Board User’s Guide DOCUMENT REVISION HISTORY Revision A (March 2009) • Initial Release of this Document. DS51801A-page 4 © 2009 Microchip Technology Inc.
MCP6V01 INPUT OFFSET DEMO BOARD USER’S GUIDE Chapter 1. Product Overview 1.1 INTRODUCTION The MCP6V01 Input Offset Demo Board is described by the following: • Assembly # : 102-00227-R3 • Order # : MCP6V01DM-VOS • Name: MCP6V01 Input Offset Demo Board Items discussed in this chapter include: • Kit Contents • Intended Use • Description 1.
MCP6V01 Input Offset Demo Board User’s Guide 1.3 INTENDED USE The MCP6V01 Input Offset Demo Board is intended to provide a simple means to measure the MCP6V01/2/3 op amp’s input offset voltage (VOS) under a variety of bias conditions. This VOS includes the specified input offset voltage value found in the data sheet plus changes due to power supply voltage (PSRR), common mode voltage (CMRR), output voltage (AOL) and temperature (ΔVOS/ΔTA). 1.
Product Overview • The Difference Amplifier (Diff. Amp.): - Rejects the DUT’s common mode output (VCM) - Provides additional gain (GDA ≈ 10.
MCP6V01 Input Offset Demo Board User’s Guide NOTES: DS51801A-page 8 © 2009 Microchip Technology Inc.
MCP6V01 INPUT OFFSET DEMO BOARD USER’S GUIDE Chapter 2. Installation and Operation 2.1 INTRODUCTION This chapter shows how to set up the MCP6V01 Input Offset Demo Board. Items discussed in this chapter include: • • • • • • 2.2 Required Tools Connecting the Lab Equipment Operating Conditions Calculating the DUT’s Input Offset Voltage (VOS) Converting Input Offset Voltage to Other Parameters Reducing the Measurement Noise REQUIRED TOOLS • Lab Power Supplies: - Two outputs - 0V to 5.
MCP6V01 Input Offset Demo Board User’s Guide 2.4 OPERATING CONDITIONS This board works most effectively at room temperature (near +25°C). Measurements at other temperatures should be done in an oven where the air velocity is minimal. The power supply (VDD) should be between 1.8V and 5.5V. The common mode voltage (VCM) needs to be between 0.3V and VDD – 0.3V for proper operation of this demo board. 2.
Installation and Operation Example 2-1 gives an example of how VOST changes with the common mode input voltage (VCM). EXAMPLE 2-1: COMMON MODE CHANGE EXAMPLE Given: VOST = 0.5 µV, VCM = 0V VOST = 1.0 µV, VCM = 5V Then: ΔVOST = 0.5 µV ΔVCM = 5.0V CMRR = 5.0V / 0.5 µV = 10 V/µV = 140 dB 2.6.2 Application When the common mode voltage (VCM) is changed on this demo board, the output voltage (VOUT) is forced to change by the same amount. There is no means provided to independently change VCM and VOUT.
MCP6V01 Input Offset Demo Board User’s Guide TABLE 2-2: ESTIMATES Operating Inputs VDD (V) TA (°C) 1.8 and 5.5 -40 to +125 +25 5.5 1.8 Estimate Equations (Note 1) 1/AOL = 0, by assumption 1/PSRR = (VOST_2 – VOST_5) / (3.7V) µV/V µV/V -40 VOS = VOST_8 µV +25 VOS = VOST_2 µV +85 VOS = VOST_9 µV +125 VOS = VOST_10 µV -40 to +125 ΔVOS/ΔTA = (VOST_10 – VOST_8) / (165°C) µV/°C +25 1/CMRR = {(VOST_4 – VOST_3) / (4.5V) µV/V +25 VOS = VOST_5 µV 1/CMRR = (VOST_7 – VOST_6) / (1.
MCP6V01 INPUT OFFSET DEMO BOARD USER’S GUIDE Chapter 3. Possible Modifications 3.1 INTRODUCTION This chapter shows simple modifications to the MCP6V01 Input Offset Demo Board: • Changing the DUT • Connecting a Chip Select Pin to Ground 3.2 CHANGING THE DUT Change the DUT (see Figure 3-1) to the MCP6V06 Op Amp as follows: 1. Remove U1 from the PCB, using a de-soldering tool. 2. Solder a MCP6V06 op amp in its place. Use a MCP6V06 in a SOIC-8 package.
MCP6V01 Input Offset Demo Board User’s Guide 3.3 CONNECTING A CHIP SELECT PIN TO GROUND The DUT can be changed to the MCP6V03 or MCP6V08 op amps with chip select. If desired, their Chip Select pin (pin 8) can be forced to ground. This is done as follows (see Figure 3-2): 1. Solder one end of a wire to the DUT’s pin 8. Pin 8 is next to the U1 reference designator on the PCB (not next to the DUT label) 2. Solder the other end of the wire the closest ground via on the PCB.
MCP6V01 INPUT OFFSET DEMO BOARD USER’S GUIDE Appendix A. Schematics and Layouts A.1 INTRODUCTION This appendix contains the schematics and layouts for the MCP6V01 Input Offset Demo Board. The Gerber files for this board are available on the Microchip website (www.microchip.com) and are contained in the “00227R3_Gerbers.zip” zip file . A.2 SCHEMATIC See below the circuit diagram. On the left is the DUT (U1), which produces the common mode voltage plus the DUT’s input offset (VOS) times a gain.
MCP6V01 Input Offset Demo Board User’s Guide BOARD SCHEMATIC (Continued) M A.2 DS51801A-page 16 © 2009 Microchip Technology Inc.
Schematics and Layouts A.3 COMBINATION OF THE TOP SILK SCREEN AND TOP METAL LAYERS A.4 TOP SILK SCREEN © 2009 Microchip Technology Inc.
MCP6V01 Input Offset Demo Board User’s Guide A.5 TOP METAL LAYER A.6 BOTTOM METAL LAYER DS51801A-page 18 © 2009 Microchip Technology Inc.
MCP6V01 INPUT OFFSET DEMO BOARD USER’S GUIDE Appendix B. Bill Of Materials (BOM) B.1 MCP6V01 INPUT OFFSET DEMO BOARD BOM The BOM in Table B-1 corresponds to Figure 2-1; it shows all of the components assembled on the PCB. Table B-2 shows additional parts that come in the ESD protection bag that the user, if needed, installs. TABLE B-1: Qty BILL OF MATERIALS FOR ASSEMBLED PCB Reference Description Panasonic® Part Number 7 C3, C4, C7, C10, C14, C17, C18 5 C1, C2, C8, C13, C16 1.
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