TPS61390EVM-020: Power supply for APD pin

Jonathan Geronga

Part Number: TPS61390EVM-020
Other Parts Discussed in Thread: TPS61390

Hi Team,

Our customer would like to confirm if the APD pin voltage out in TPS61390 should be the same with VOUT?
If the VOUT will be 80V, will the APD pin voltage will also be 80V?

Our customer tried simulating the schematic using LTSpice with this EVM and the VOUT is going up to 80V but the APD pin is not showing the same voltage.

The customer is confused if he will connect his APD device to the JP1-APD or to J3-VOUT.

Thanks!

Jonathan

over 5 years ago

0 Helen chen over 5 years ago

TI__Mastermind 40080 points

Dear Sir,

The APD voltage is around 2 V lower than the Vout. And the voltage ripple at the APD pin is at least 20 times smaller than the ripple at the Vout .

What is your target voltage at APD pin.

80V is quite high, very near the maximum output capability!

And what is your maximum APD current?

0 Jonathan Geronga over 5 years ago in reply to Helen chen

TI__Expert 7930 points

Hi Helen,

Thank you for your response and support.
Base on the customer, the target voltage was ~55V and the current is less than 1mA.

What voltage does the customer should expect in the APD pin?

Regards,

Jonathan

0 Helen chen over 5 years ago in reply to Jonathan Geronga

TI__Mastermind 40080 points

Dear Sir，

You can find it from the TPS61390 datasheet. It is around 2.5V. So if you want to set the APD voltage at 55V, then you should set the boost output voltage at 57.5V.

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TPS61390EVM-020: Power supply for APD pin