REF43 Trim pin function

Paul,

The REF43 came out in 1988 and the product folder is a little skimpy.  All available public

data is on the data sheet.  The resistor divider is trimmed, so it could be trimmed up or down.

The untrimmed resistor tolerance is probably 10-20%, so you can't calculate the max swing

for the trim pin.   The spec has a typical of 95 mV which is huge.  The trim pin goes directly

into the heart of the bandgap, so the more you move the output voltage, the worse

the tempco gets.  I would not trim more than 5mV, which would take out any intial offset on

the G grade part.  As shown, you can move at least 15 times that..

Harry

Paul,

The REF43 came out in 1988 and the product folder is a little skimpy.  All available public

data is on the data sheet.  The resistor divider is trimmed, so it could be trimmed up or down.

The untrimmed resistor tolerance is probably 10-20%, so you can't calculate the max swing

for the trim pin.   The spec has a typical of 95 mV which is huge.  The trim pin goes directly

into the heart of the bandgap, so the more you move the output voltage, the worse

the tempco gets.  I would not trim more than 5mV, which would take out any intial offset on

the G grade part.  As shown, you can move at least 15 times that..

Harry