TPS61194: what will be the Short to ground fault behavior and recovery ?

Hi Chaitanya,

OCP and LED short fault will appear. If these faults happens, device will shutdown and there is no output. 

Pull VIN or EN low then high will clear faults.

BR,

Robin

Hi Robin,

We have configured the driver with the following configuration  (Refer TPS61194_Schematics attachment)  : 

RIset = 49k

Rfset = 160k

PWM=100%

Feedback: R1= 470k, R2=130k

The fault pin is pulled up with 10k.

We have performed the Output (Anode) short to GND  and observed No-Fault is Reported and at the fault instance output becomes zero and once the fault is removed. The driver is still shutdown mode.

Attaching the waveform for your reference.

Regards 

Chaitanya

Hi Robin

Any update regarding this query?

we are waiting for your reply.

Regards

Chaitanya

Hi Chaitanya,

TPS61194 has only LED open/short, VIN OVP, VIN UVLO and TSD fault detection, and the LED short/open fault is detected by current sink headroom voltage, pls. refer to figure 11 of datasheet. So LED short cannot be detected by the way you experimented because this fault condition is: one ore more current sink s are above shorted detection level (HIGH_COMP of figure 11) and at least one current sink has normal voltage.

BR,

Robin

Hi Robin

 I am clear about the faults and their recovery mechanisms described in the datasheet and we are assessing the fault which I mentioned earlier.

Is it the expected behavior of the device to go to shutdown mode without reporting the fault out?

If the fault is not reported then why it is not recovering once the fault is removed?

Regards

Chaitanya

Hi Chaitanya,

We will have a bench test on TPS61194EVM to verify you mentioned phenomena.

BR,

Robin

Hi Robin

Can you perform this test with your team on your EVK and update us.

Regards

Chaitanya

Hi Chaitanya,

OK, pls. wait for our test result.

BR,

Robin

Hi Robin

Any update from your side on the test result.

Regards 

Chaitanya

Hi Chaitanya,

I had got the EVM board and will have a test later.

BR,

Robin

Hi Robin

I am waiting for the test results.

Regards

Chaitanya

Hi Robin

Any updates from your side.

Regards

Chaitanya

Hi Robin

This is been a month, we haven't heard from you,  Can you please update what is the status.

Regards

Chaitanya

Hi Chaitanya,

Sorry for reply so late! Bench test has been arranged. 

BR,

Robin

Hi Chaiyanya,

Please refer to the below bench test result based on TPS61194EVM. When Vout is connected to ground, FLT signal and Vout becomes low. Besides, when disconnecting Vout with ground, the output could return to normal situation.