Watching Dog timer recommendation

Zhihong Huang

Other Parts Discussed in Thread: TPS3700, TPS3431, TPS3430, TMS320F28062, TPS3850, TPS386000

Hi team

In order to pass the safety test in the field of home appliances, we have done many schemes for our customers. Now we need to provide customers with a solution made of watchdog chip, which needs the function of Watchdog with overvoltage and undervoltage detection.

1.The overvoltage threshold is 3.6V.

2. The undervoltage threshold is 2.9v.

Could you please provide me a recommendation of the watchdog timer or solution to me?

Thanks

Best Regards,

Wesley Huang

Email: wesley-huang@ti.com

over 6 years ago

0 Marcoo Z over 6 years ago

TI__Mastermind 19590 points

Hi Wesley,

If this E2E thread goes into customer details, please e-mail me.

Do you want a single device solution or would a combination of multiple devices work?

For a single device solution, the closest we have is a TPS3850H33DRCR.

This device has a OV = 3.531V, UV = 3.069V.

For a multi device solution,

TPS3700 for OV + UV

And a TPS3430 or TPS3431 for watchdog.

How much functionality do they need on the watchdog? Do they need a window watchdog?

-Marcoo

0 Zhihong Huang over 6 years ago in reply to Marcoo Z

TI__Intellectual 1550 points

Hi Marcoo

Thank you for your recommendation, which helped me solve the problem.

I also need you to recommend the R1 and R2 value if I want to use the Adjustable vision of TPS3850 to monitor the VCC of TMS320F28062 and the threshold is shown below:

1.The overvoltage threshold is 3.6V.

2. The undervoltage threshold is 2.9v.

Best Regards,

Wesley Huang

Email: wesley-huang@ti.com

0 Zhihong Huang over 6 years ago in reply to Zhihong Huang

TI__Intellectual 1550 points

The VCC is 3.3V

0 Marcoo Z over 6 years ago in reply to Zhihong Huang

TI__Mastermind 19590 points

Hi Wesley,

The adjustable TPS3850 does not have overvoltage protection.

The R1 and R2 values will only be set for undervoltage.

If you are open to a larger device multichannel devices, the TPS386000 can be set for undervoltage and overvoltage.

http://www.ti.com/lit/ds/symlink/tps386000.pdf

Or to use a TPS3700 for UV + OV and a TPS3430/1 for watchdog.

Regardless, this will be a 2 device solution.

If you device on which one you want to use, i can help you with the resistor values.

How much functionality do you need in a watchdog?

Power management

Power management forum

Watching Dog timer recommendation