TL494: Schematic Review

Rahul Sharma

Intellectual 320 points

Part Number: TL494

Tool/software:

Dear TI Expert,

1. Please Review the circuit schematic and comment.

2. In this design, we have found in one of the PCB out of 100 PCB MOSFET drive pin switching shift to 4V to VCC.

3. We are unable to Analyse why it has shifted 4V to VCC. Rest of the function IC is working fine. For your kind of information Replace Fault IC with new IC maintaining all component of PCB unchanged board is working fine.

Thanks

Rahul Sharma

Lithion Power Private Limited

9 months ago

0 Ning Tan 9 months ago

TI__Genius 12795 points

Rahul,

Please give us some time to get back to you.

Thanks for the understanding.

0 Hong Huang 9 months ago in reply to Ning Tan

TI__Guru 73965 points

Hi,

The schematics review usually takes about a week.

2. 3.

Can you try to put that 4V unit to a different board to see the issue can be duplicated or disappeared?

0 Rahul Sharma 9 months ago in reply to Hong Huang

Intellectual 320 points

Thanks for your effort we will wait for a week.

After putting Faulty IC on working Board. we have found full faulty IC; we have measured voltage 2.5V with respect to Gnd.

0 Hong Huang 9 months ago in reply to Rahul Sharma

TI__Guru 73965 points

Hi,

Please make clear which IC (U36 or U38?) and which pins and their voltage shift - please provide their waveforms along with Vcc?

If U36, pin 9 and 10, please their waveforms along with pin 8 and 11 waveforms to help understand the shift you mean, Please provide both good and bad waveforms.

0 Hong Huang 8 months ago in reply to Hong Huang

TI__Guru 73965 points

Hi,

On your schematics,

- U36 pin 16, 2IN+, connected to GND through R342, but pin 15 still shows intended control. Pin 15 cannot go to below 0 so Error Amplifier 2 (EA2) of U36 is not controllable in your design from your intention. Your intention to control EA2 does not work. What is your intention to do with EA2?

0 Hong Huang 8 months ago in reply to Hong Huang

TI__Guru 73965 points

Hi,

As no further communication for a while, I will close this thread. Please re-open if needed.

Power management

Power management forum

TL494: Schematic Review