• Join
  • Sign In with my.TI Login
Texas Instruments
  • Products
  • Applications
  • Tools & Software
  • Support & Community
  • Sample & Buy
  • About TI
Sample & Purchase Cart Sample & Purchase Cart
  • Search
  • Advanced
TI E2E™ Community
  • Support Forums
  • Blogs
  • Groups
  • Videos
  • 简体中文
  • More ...
TI Home » TI E2E Community » Support Forums » Applications » Motor Drivers » Motor Drivers Forum » DRV8432 hidden output short
Share
Motor Drivers
  • Forum
  • Announcements
  • E2E Wiki
Options
  • Subscribe via RSS

DRV8432 hidden output short

DRV8432 hidden output short

  • Sebastien Bourdage
    Posted by Sebastien Bourdage
    on Jun 18 2012 12:23 PM
    Intellectual330 points

    I recently made some test boards to get the DRV8432 running for our application, but I'm experiencing high currents with no load when I apply a PWM signal. See schematic below:

    Not shown in the above diagram is large bypass caps for the PVDDs (I will eventually be driving very inductive loads). There's also regulators for GVDDs to keep them at 12V.

    I have a power supply connected to the circuit, current limited to 2A @ 17V. When I apply a PWM signal, the current hits maximum and the voltage drops to around 11V, the DRV832 starts heating up (I had removed the heatsink to feel for heat). I have tried removing U21 and U26 incase these chips where causing problems, but this did not make a difference. I can't find any shorts. I have two boards made, and they both behave the same way which makes me think I may have missed something in the design.

    The PWM signals I'm sending are either complementary or all low. The high current does not occur when all PWM signals are low, it only happens when I apply a PWM signal. The fault pin does not go high, but I'm sure OTW will eventually if I keep the thing running.

    I'm going to try removing those caps that shouldn't really be there (C59,C61, C71, C72, they should have been connected to the PVDDs, but I can't image this causing the problem)

    I can't think of anything else that could be causing the high current through the DRVs except for faulty chips, but what are the chances of two faulty chips? hmmm....

    PWM Frequency is around 250Khz, and I'm only doing 50% for now, so boot-straps should be functioning fine.

    Can anybody see something I may have missed? Or possible things I could try to debug this?

    Thanks,

    -Seb

    Report Abuse
    • Reply
    You have posted to a forum that requires a moderator to approve posts before they are publicly available.
  • Sebastien Bourdage
    Posted by Sebastien Bourdage
    on Jun 18 2012 12:41 PM
    Intellectual330 points

    Nevermind, it totally was those caps I put in the wrong place. I guess their impedance was low enough to cause that "short".

    Lesson learned.

    Thanks anyway.

    Report Abuse
    • Reply
    You have posted to a forum that requires a moderator to approve posts before they are publicly available.
TI E2E™ Community
  • Support Forums
  • Blogs
  • Videos
  • Groups
  • Site Support & Feedback
  • Settings
TI E2E™ Community Groups
  • TI University Program
  • Make the Switch
  • Microcontroller Projects
  • Motor Drive & Control
Other Communities
  • Deyisupport
  • Designsomething.org
  • beagleboard.org
  • TI on Element 14
  • TI on TechXchangeSM
Other Technical & Support Resources
  • WEBENCH® Design Center
  • Product Information Centers
  • Technical Documents
  • TI Design Network
  • TI Technical Articles
  • TI Training

All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.

Content on this site may contain or be subject to specific guidelines or limitations on use. All postings and use of the content on this site are subject to the Terms of Use of the site; third parties using this content agree to abide by any limitations or guidelines and to comply with the Terms of Use of this site. TI, its suppliers and providers of content reserve the right to make corrections, deletions, modifications, enhancements, improvements and other changes to the content and materials, its products, programs and services at any time or to move or discontinue any content, products, programs, or services without notice.

Follow Us Texas Instruments on Facebook Texas Instruments on Twitter Texas Instruments on LinkedIn Texas Instruments on Google+
TI Worldwide | Contact Us | my.TI Login | Site Map | Corporate Citizenship | mobile m.ti.com (Mobile Version)

TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs and
embedded processors, along with software, tools and the industry’s largest sales/support staff.

© Copyright 1995-2013 Texas Instruments Incorporated. All rights reserved.
Trademarks | Privacy Policy | Terms of Use