TPA3116D2: persisting fault condition

Dominik Wagner

Part Number: TPA3116D2

Hi,

I worked with the TPA3116D2 and tried BTL and PBTL, but it was always stuck in the fault/protected state (faultz = low).

The basic circuitry is as seen below

Sync was left floating
SD=5V
Mute=GND
Output plug open

Measurements:
GVDD=6.9V
PLIMIT=6.9V
FAULTZ=0.1V
RINP/N=2.8V directly on the pins

PVDD is either 12.5V or 25V, but the results remained the same. Also tried ferrite beads and 1nF caps instead of the 10uH coils with 1uF caps or leaving the secondary site open (just bootstrap caps).

This exact behaviour was seen on multiple boards.

Regards,

Dominik

over 5 years ago

0 Shawn Zheng over 5 years ago

TI__Mastermind 24835 points

Hi Dominik,
From the above SCH, PBTL mode is used here. Did you pull the FAULT pin to High voltage by a 100kOhm resistor? When there is no input signal on the AMP input, does the issue still occur? Please help to check whether there is any problem on the discrete components(sepecially bootstrap capacitors).
Best regards,
Shawn Zheng

0 Dominik Wagner over 5 years ago in reply to Shawn Zheng

Prodigy 30 points

According to the data sheet, faultz is just an output, so is the 100k to HIGH really needed?

SD and MUTE will be controlled by a microcontroller later, but are manually switched on the test circuit right now.

The voltages on the bootstrap pins are looking good as far as I can tell (around 7-8V without signal).

The issues occurs with and without an input signal.

0 Shawn Zheng over 5 years ago in reply to Dominik Wagner

TI__Mastermind 24835 points

Hi Dominik,
The FAULT is open-drain gate structure, so you need to drive this pin to High level by 100KOhm resistor to make it work.
Best regards,
Shawn Zheng

0 Dominik Wagner over 5 years ago in reply to Shawn Zheng

Prodigy 30 points

Thanks for the clarification. It's working perfectly now with the faultz pulled up to PVCC.

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TPA3116D2: persisting fault condition