Tool/software:
Hi TI Experts,
Please analyse the following scenario:
During some OVP tests, I've noted that the FLT pin remains activated (LOW) even after the OVP condition is over.
My original circuit drives a solenoid driver circuit, and I don't use the TPS26630 reverse polarity protection, so the B_GATE and DRV pins are floating, IN and IN_SYS are connected to the same node.
To exclude any behavior of my original circuit, I ported the scenario to the TPS26630-33EVM, and the same problem occurs.
EVM Adaptation:
D2, Q1 and Q2 are unmounted;
R14 and R15 are mounted;
MODE is set to GND (auto-retry);
And the OVP limit is the EMV original limit (about ~33V)
The OVP pulse is 500ms in 36V and returns to 24V.
There is no load in the output.
Yellow: VIN; Blue: VOUT; GREEN: \FLT
It doesn't matter if I end the OVP condition and wait a long period of time; the /FLT remains LOW.
I noted that if I put any load (>1mA) on the output, the behavior acts as expected:
Another behavior: when I interact with the DRV pin (like touching my finger or reading the voltage with a multimeter), the /FLT flag returns to the expected state.
The problem is reverse current detection, related to discharge or not the output voltage held by the capacitor after OVP, but in my operation, the solenoid driver remains disabled most of the time.
The behavior doesn't occur with the reverse polarity protection mounted.
How can I skip this issue without using the \SHDN pin or power cycling the source?
Regards,
Ricardo Borges