Welcome to the Sequencers Section of the TI E2E Support Community. Ask questions, share knowledge, explore ideas, and help solve problems with fellow engineers. To post a question, click on the forum tab then "New Post".
Q: TPS3828-33 watchdog failed by 1170817
I have a customer using the TPS3828-33 and he have a problem that the reset is not activated when the WDI pin is LOW.
There are two cases:
1. If WDI stops toggle and stays HIGH then RESET will go active after 1,2 sec.
2. If WDI stops toggle and stays LOW then RESET will NOT go active after 1,2 sec.
In both cases WDI will be held low during RESET.
A: Re: TPS3828-33 watchdog failed by 10449
It is confirmed that the microprocessor watchdog output did not have enough drive strength to properly pull the TPS3828 WDI pin high and low. The TPS3828 will not generate a reset if the WDI pin is open or driven with a high impedance. This is proper operation and is how the IC was designed to function.
If the microprocessor does not have enough drive strength to drive the WDI pin directly, connect a pullup resistor from WDI to VCC. Connect an N-CH FET from WDI to ground with source connected to ground and the drain connected to WDI. Connect the uP output to the gate. When the uP output is high impedance or low, the FET is off and the WDI input is pulled high which will generate a reset. When the uP output is high, the WDI pin is pulled to ground.
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.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.