Texas Instruments LOG114EVM User Manual
  1. Manuals
  2. Brands
  3. Texas Instruments Manuals
  4. Motherboard
  5. LOG114EVM
  6. User manual
Texas Instruments LOG114EVM User Manual

Texas Instruments LOG114EVM User Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
This user's guide describes the characteristics, operation, and use of the LOG114EVM evaluation board. It
discusses how to set up and configure the board hardware, and reviews various methods of using the
evaluation module (EVM). Throughout this document, the terms evaluation board, evaluation module, and
EVM are synonymous with the LOG114EVM. This document also includes an electrical schematic, printed
circuit board (PCB) layout drawings, and a parts list for the EVM.
.....................................................................................................................
1
2
3
4
Using the LOG114EVM
5
Verifying Results
6
LOG114EVM Documentation
1
2
LOG114EVM Level Shifter
3
LOG114EVM Signal Path
4
High-Current Linearity Correction Circuit
5
LOG114EVM Complete Circuit
6
7
8
9
10
11
12
13
14
15
16
17
All trademarks are the property of their respective owners.
SBOU110 - September 2011
Submit Documentation Feedback
................................................................................................................
..........................................................................................
...................................................................................................
...........................................................................................................
............................................................................................
................................................................................................................
.................................................................................................
..................................................................................................
................................................................................
............................................................................................
.........................................................................................
...............................................................................................
........................................................................................
..........................................................................................
.......................................................................................
....................................................................................
Copyright © 2011, Texas Instruments Incorporated
LOG114EVM User Guide
Contents
List of Figures
...........................................
......................................................................
............................................................................
..............................................
..........................................................................
User's Guide
SBOU110 - September 2011
.......................................
LOG114EVM User Guide
2
3
7
11
12
13
2
3
4
5
6
7
7
8
8
9
10
11
12
13
14
14
14
1

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the LOG114EVM and is the answer not in the manual?

Questions and answers

Related Manuals for Texas Instruments LOG114EVM

Summary of Contents for Texas Instruments LOG114EVM

  • Page 1: Table Of Contents

    SBOU110 – September 2011 LOG114EVM User Guide This user's guide describes the characteristics, operation, and use of the LOG114EVM evaluation board. It discusses how to set up and configure the board hardware, and reviews various methods of using the evaluation module (EVM). Throughout this document, the terms evaluation board, evaluation module, and EVM are synonymous with the LOG114EVM.

  • Page 2: Overview

    Figure 1. LOG114EVM Getting Started Tested at the factory over a wide range of input currents, the LOG114EVM comes ready to use and includes this Quick Start User’s Guide. Use of the LOG114EVM requires a 5-V power source, an input source such as a photodiode or resistor, and a digital voltmeter or oscilloscope.

  • Page 3: Log114Evm

    The LOG114EVM comes completely assembled and constructed to operate on a single 5-V power supply. The circuit used in the LOG114EVM is designed to operate over a wide range of input currents (10 nA to 10 mA) and scales the output voltage from 1.15 V to 2.75 V. There are three distinct sections to the LOG114EVM circuit: a precision level shifter, the signal path, and the high-current linearity correction section.
  • Page 4 (from the Level Shifter) VOUT Figure 3. LOG114EVM Signal Path High-Current Linearity Correction The LOG114 is capable of handling a wide dynamic range of currents, from less than 100 pA in a carefully designed PCB to 10 mA in high-current applications. Because the LOG114 was designed for high speeds,...
  • Page 5 A4 in a manner that subtracts the error signal from the output of the EVM, V VBIAS (from the Level Shifter) PHOTO VREF VERR 5 kW 1 kW 21.5 kW Figure 4. High-Current Linearity Correction Circuit SBOU110 – September 2011 LOG114EVM User Guide Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated...
  • Page 6 LOG114EVM www.ti.com Figure 5 shows the entire circuit layout of the LOG114EVM. VERR VLOGOUT VLOG 10 kW 4.3 kW VREF 1 MW 100 nF 10 kW 10 kW PHOTO VREF VOUT VREF VERR 100 nF 1 kW OPA365 4.02 kW...

  • Page 7: Connecting To The Log114Evm

    EVM, including the use of a grounded wrist strap at an approved ESD workstation. Basic Connections The connections for 5 V and ground are clearly marked on the LOG114EVM PCB. Figure 6 shows how to properly connect the power supply to the connector.

  • Page 8: Using A Photodiode Without The High-Current Linearity Correction Circuitry

    9. When connecting the photodiode in this configuration, the high-current linearity correction circuitry is bypassed. Figure 9. Applying a 0.5-V Reverse Bias to the Photodiode SBOU110 – September 2011 LOG114EVM User Guide Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated...

  • Page 9: Using A Resistor To Create An Input Current

    I . In this case, the input current I is determined by Equation BIAS Figure 10. Using a Resistor to Create an Input Current SBOU110 – September 2011 LOG114EVM User Guide Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated...

  • Page 10: Using A Resistor And The High Current Linearity Correction Circuitry

    (I 3) · = 2 + 5 kW · 21.5 kW The voltage at the V terminal is given by Equation = 2 V · SBOU110 – September 2011 LOG114EVM User Guide Submit Documentation Feedback Copyright © 2011, Texas Instruments Incorporated...

  • Page 11: Log114Evm Components

    Using the LOG114EVM Once the LOG114EVM has power applied and an input signal, easy access terminal pins allow for quickly evaluating the circuit performance. Connect a digital voltmeter or oscilloscope to any of the terminals to make the measurements.

  • Page 12: Log114Evm Measured Results

    Verifying Results Making measurements on the LOG114EVM is fast and easy. Connect a digital voltmeter or oscilloscope to the terminal of interest and record the results. Included with the graph of measured results is a table of results for common values of input currents. In Figure 13, two curves are shown.

  • Page 13: Log114Evm Board Schematic

    LOG114EVM Documentation This section contains the complete bill of materials and PCB layout for the LOG114EVM. NOTE: These board layouts are not to scale. These image are intended to show how the board is laid out; they are not intended to be used for manufacturing LOG114EVM PCBs.

  • Page 14: Pcb Layout

    PCB Layout Figure 15 through Figure 17 show the PCB layout of the LOG114EVM. Figure 15. LOG114EVM: Top Side Composite Drawing Figure 16. LOG114EVM: Top Copper Layer Figure 17. LOG114EVM: Bottom Copper Layer SBOU110 – September 2011 LOG114EVM User Guide Submit Documentation Feedback Copyright ©...

  • Page 15: Bill Of Materials

    LOG114EVM Documentation www.ti.com Bill of Materials Table 2 lists the bill of materials for the LOG114EVM Table 2. LOG114 Bill of Materials Item No Count Value Ref Des Description Mfr Part Number 21.5 kΩ Resistor, 21.5 kΩ 1/10W 1% 0603 SMD...

  • Page 16: Evaluation Board/Kit Important Notice

    Evaluation Board/Kit Important Notice Texas Instruments (TI) provides the enclosed product(s) under the following conditions: This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSES ONLY and is not considered by TI to be a finished end-product fit for general consumer use. Persons handling the product(s) must have electronics training and observe good engineering practice standards.

  • Page 17: Regulatory Compliance Information

    Any exceptions to this are strictly prohibited and unauthorized by Texas Instruments unless user has obtained appropriate experimental/development licenses from local regulatory authorities, which is responsibility of user including its acceptable authorization.
  • Page 18 FCC Interference Statement for Class B EVM devices This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
  • Page 19 Also, please do not transfer this product, unless you give the same notice above to the transferee. Please note that if you could not follow the instructions above, you will be subject to penalties of Radio Law of Japan. Texas Instruments Japan Limited (address) 24-1, Nishi-Shinjuku 6 chome, Shinjuku-ku, Tokyo, Japan http://www.tij.co.jp...
  • Page 20 FDA Class III or similar classification, then you must specifically notify TI of such intent and enter into a separate Assurance and Indemnity Agreement. Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2012, Texas Instruments Incorporated...

  • Page 21: Important Notice

    IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue.

Table of Contents