PTH7800A Problem

Matthew Sheridan

I'm trying to use the PTH7800A as a -12v supply but it is outputting a +12v supply instead, is there something obvious that I am doing wrong? Has anyone else experienced this problem? Thanks.

over 13 years ago

0 Tom Guerin over 13 years ago

TI__Mastermind 38230 points

Matthew:

The PTN78000Axx with (+) vin and (-) vout has input voltage limit of (+) 20V for -12Vout. The absolute input voltage is defined as (32- IV_OI).

Note: PTN78000A pin 1 is (-)Vout as per the schematic and pin 5 is ground . However, PTN78000W (+Vin to +Vout ) pin 1 is ground. and pin 5 is (+)Vout

Tom

0 Matthew Sheridan over 13 years ago in reply to Tom Guerin

Prodigy 20 points

My input voltage is around +17V and I have the device configured as above, I am using a 2K resistor so I get ~+12V on the VO pin, but this is a positive voltage not a negative one, is there something maybe to do with the capacitors that could cause this to happen?

0 Tom Guerin over 13 years ago in reply to Matthew Sheridan

TI__Mastermind 38230 points

Matthew;

Can you sned me an e-mail with your contact information.

Tom

tguerin@ti.com

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PTH7800A Problem