TPS23753 circuit part alternatives

Navin Narayanan

Other Parts Discussed in Thread: TPS23753, CSD17527Q5A

Hi All

I'm using TPS23753 in the same configuration as seen in the TPS23753AEVM-235 circuit.

[http://www.ti.com/lit/ug/slvua27a/slvua27a.pdf]

However i'm not using the diode rectifier shown in the schematic, I'm using MB4S bridge rectifier. Rest of the circuit is the same.

For the transformer, I'm using Wurth 749119350 [katalog.we-online.de/.../749119350.pdf] instead of Coilcraft NA6223-AL with changes to pinout as shown below

Coilcraft	Wurth
3	5
4	6
1	3
2	1
10	10,11
7	9,8,12
6	7

For the output mosfet, i'm using BSC057N08NS3 instead of CSD17527Q5A.

Above alternatives have been proven to work and produce stable 5V.

I would like to know if there are any alternatives for input side mosfet FDS86244 and optocoupler TCMT1107.

Could anyone please confirm if I can replace:

FDS86244 with SI1480DH [http://www.farnell.com/datasheets/1760640.pdf]

or FDC8601 [http://www.farnell.com/datasheets/2000412.pdf]

or FDC3612 [http://www.farnell.com/datasheets/1639782.pdf]

Thank you for your assistance

over 8 years ago

Navin Narayanan over 8 years ago

Prodigy 130 points

Also can I use VOS617A [http://www.vishay.com/docs/83497/vos617a.pdf] in place of TCMT1107?

Darwin Fernandez over 8 years ago in reply to Navin Narayanan

TI__Mastermind 40580 points

Hi Navin,

For the primary, you may want to check VDS initial voltage spike when using 100V FETs. You may need to adjust the snubber. This might decrease the efficiency.

For the opto, the TCMT datasheet recommends to use the 'B' version. The forward voltage is slightly different. You may need slightly adjust the biasing resistor. However, be sure to use the -7 part to keep the same CTR .

You can try verifying this on the EVM as a start.

Regards,
Darwin

Navin Narayanan over 8 years ago in reply to Darwin Fernandez

Prodigy 130 points

Hi Darwin

Thanks for your update, I will verify some of these parts on our circuit and update results soon

Navin Narayanan over 8 years ago in reply to Darwin Fernandez

Prodigy 130 points

I have used the aforementioned parts to replace those that are specified on the schematic, and I confirm that the circuit works. It produces 5V output.
I havent measured efficiency, but these parts produce the necessary 5V that I am after. I hope this helps readers who are looking for alternative parts for this particular circuit

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TPS23753 circuit part alternatives