uPA63H

[xXBrunoXx]

Hi, anyone have datasheet for uPA63H ?
Are they worth using?. as diff amp
" LTP "

 

[rayma]

This may be all there is.

TI makes some.
https://www.ti.com/power-management...s/products.html#1143=Dual;Dual Common Source&

 

[xXBrunoXx]

@rayma Thank you.

 

[rayma]

How did you get this, RFE?

 

[xXBrunoXx]

Toshiba aurex sc-m15.
Its working but on low volume one channel cuts out until you turn it a but up and then again works, cuts again on low volume.
Haven't gotten to take a look in it but looked in the service manual searched for the j fets for curiosity.

 

[rayma]

More likely a corroded connection or solder joint. Suspect all switches, connectors, etc.
A bad semi wouldn't do that. Signal trace with a scope, but it's probably after the volume control.

 

[StevenOH]

The characteristics.

 

[xXBrunoXx]

@rayma Thank you, I will take it apart these days and take a look.

 

[xXBrunoXx]

@StevenOH Thank you Steven!.

 

[StevenOH]

And to finish the specs discussion for these dual FET I will add grades values,
measured in Japan (and which are missing in the d/s):

K1=1.5mA...3mA, K2=2.5m...4m
L1=3.5m...6m, L2=5.5m...8m,
M1=7.5m...11m, M2=10.5m...14m
N=13.5m...20m

Manufacturers usually overlap grades to play it safe.
For illustration - sample measurements for L2 and M1 (sub)grades:

 

[Bonsai]

The TI devices look like N-Chan MOSFETS and not JFETs. I might be wrong of course - apologies if I am.

The TI devices are best suited to switching applications whereas the JFET device would typically be used as a diff amp in the front end of an amplifier stage.