TPS2HB35-Q1: Short condition detection/overtemperature when using PWM

Hello Frank, 

With 100Hz (0.01 sec period) PWM the HSS will operate well within its bounds outlined in the switching characteristics. Failing by overtemperature fault due to switching is highly unlikely. With LATCH unused, the device will auto-retry after a fault. In the datasheet Figure 43. displays the auto-retry behavior. 

Best, 

Alan

Hi Alan,

Can we configure the tRETRY time? 

During the retry period, will ENx pulled low influence the VOUT or RETRY? What is the SNS pin status during the retry?

Thanks

Best,

Frank

Hello Frank, 

The tRETRY time is 1-3ms

There are two protection features which, if triggered, will cause the switch to automatically disable:
• Thermal Shutdown
• Current Limit
When any of these protections are triggered, the device will enter the FAULT state. In the FAULT state, the fault
indication will be available on the SNS pin.

Figure 40 in the datasheet shows the immediate current limit switch off and the retry behavior. 

Best, 

Alan

Hi Alan,

Thanks, got it.

I more question is, do we have any insight that if this kind of application(multiple retry and PWM) will influence the lifetime? Customer would like to learn if it can operate for 24 hours.

Thanks

best,

Frank

Hello Frank, 

I will follow up morning of 9/25

BR, 

Alan

What is the expected duty cycle of the PWM?

This will help determine if the device will fault during runtime and influence lifetime.

Best, 

Alan