PGA309 + TPS7A41 under electrically fast transient test

weiming zhang

Other Parts Discussed in Thread: PGA309, TIPD126, TIPD153, TIPD155

Hello

our pressure transmitter are mainly formed by your PGA309 programmable conditioner and power supply chip TPS7A41. in order to pass electrically fast transient test, we add some ferrite beads and TVS etc. see attached file below.

but the voltage output changes about from 1V to 2V even to 3V when the applied voltage reaches 3kV.after the test, the voltage output returns to 1V and no components are damaged.

our aim is 4kV,could you give me some advices?

best regards

Weiming

over 10 years ago

0 Ian Williams over 10 years ago

TI__Mastermind 27715 points

Hello Weiming,

Here are some tips to ensure that their design passes the EFT tests, as well as other EMC tests:

Place a 100nF capacitor across the power supply lines, as close as possible to the power connector.
Place a TVS diode between the recommended 100nF capacitor and the power supply pin of the PGA309
Use a copper GND plane on both layers of the PCB
Place ferrite beads on the PCB in series with the power supply line
Place large ferrite core wire terminators on the wires providing power to the board, making sure to wrap the wires around the cores several times for best EMI rejection. The large ferrites look like this:

You can refer to these CerTIfied TI Precision Designs for more examples on how to pass EMC tests:

Best regards,

Ian Williams
Linear Applications Engineer
Precision Analog - Op Amps

0 weiming zhang over 10 years ago in reply to Ian Williams

Intellectual 270 points

Hello Ian

thank you.
But I can not access to the large ferrites picture.

best regards,
Weiming

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PGA309 + TPS7A41 under electrically fast transient test