PTH08080W input cap selection

Paul Murphy1

Other Parts Discussed in Thread: PTH08080W

I'm having trouble finding the exact recommended input caps from the PTH08080W datasheet.
I have a 6V-17V input voltage, and need 5V out. Load will vary wildly from 100mA to 2A.

I've selected a 348 ohm resistor.
Will either of these capacitors work well as my input cap?
http://www.digikey.com/product-detail/en/UPM1H221MHD6/UPM1H221MHD6-ND
or maybe...
http://www.digikey.com/product-detail/en/EEV-FC1V221P/PCE3250DKR-ND

Thanks!

over 10 years ago

0 Tom Guerin over 10 years ago

TI__Mastermind 38230 points

Paul:

1. I looked at both capacitor. UPM220uF x 50V is a through hole component from Nichicon. Ripple curent is 1150mA rms. This is a good qualtiy T/H capacitor

2. Panasonic 220uF x 50V is a SMT capacitor.but it is not recommended for new designs NRND on the enclosed specification .

2A Panasonc has another series EEVFK1V331P SMT 330uf ripple current rated to 850mA rms. This is also a good capacitor.

Tom

0 Paul Murphy1 over 10 years ago in reply to Tom Guerin

Prodigy 60 points

Thanks Tom!
I can't find the EEV-FK1V331P you mention in stock anywhere. Perhaps this would be a good SMT alternative?
http://www.digikey.com/product-detail/en/UCD1H221MNL1GS/493-6390-1-ND
It is 220uf, 50V with ripple current rated to 700mA.

0 Tom Guerin over 10 years ago in reply to Paul Murphy1

TI__Mastermind 38230 points

Paul;

The Nichicon UCD 200uF and 50V rms =700mA will be fine for this applicaiton.

Thanks

Tom

0 Paul Murphy1 over 10 years ago in reply to Tom Guerin

Prodigy 60 points

I'm wondering if a capacitor with a smaller footprint will work for me. This one is 100uF, 25V, but current ripple is only rated at 600mA...
http://www.digikey.com/product-detail/en/EEE-FPE101XAP/PCE4546CT-ND

The PTH08080W datasheet specifies 650mA current ripple for the input cap. What adverse effects might I experience with this smaller 600mA cap?

0 Tom Guerin over 10 years ago in reply to Paul Murphy1

TI__Mastermind 38230 points

Paul:

The lower ripple current (rms) 600mA directly correlates to the lower capacitor life cycle. The longer life capacitor will have at least 650mA ripple current rating.

Tom

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PTH08080W input cap selection