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When using an external offset trim pot on these ICs, which supply should the pot wiper connect to?
The data sheets are inconsistent...
TLC07X data sheet: Wiper to VDD- (What's that??)
TLC08X data sheet: Wiper to VDD (Positive supply)
Application Report SLOA045 "Nulling offset voltage.." refers to TLC070 and shows wiper to VEE/GND (Negative supply)
Hi Jim,
I'm checking into this issue for you and will update this thread once we have the official answer. However, right now it looks like both the TLC07x and TLC08x would have the potentiometer wiper connected to the negative supply (or Ground if configured for single supply) for offset nulling.
John Caldwell
Analog Applications Engineer
PA Linear Apps
Thanks. I just received some TLC081's and tried the offset null to both pos and neg supplies. The neg supply works correctly.
Good to hear! I was able to double check the internal schematic of both parts at the very end of last week and confirmed that the trim should go to the negative supply. good luck with your project and please let us know if there is anything else we can help with.
Thanks!
I suggest the data sheets be corrected ;-)