I am trying to use the Texas Instruments LP2950CZ-3.0 as a voltage reference for A/D conversion with PIC18F26K22. But I have tested it outside the circuit, and it does not give 3.0V output. Instead it gives 4.55 V output on 5V input. I have two pieces and both show the same response on no-load. And the datasheet says it can give output current of 100mA but when I put a resistance of 470 Ohm as a load, then only milliVolts show up on output. Can anyone suggest what could be wrong ?
here's the schematic :
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here's the first page of datasheet :
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You have the input and output pins connected backwards which might have destroyed the IC. The datasheet shows the pins from the bottom but you have the IC faced from the top.
Is your Multimeter sufficiently accurate ???Handhelds typical %0.25-0.1 accuracy.Use a more accurate one and consider ambient temperature which is mentioned in the datasheet.
Also, these devices have tolerances and no device gives you 3.000 V exactly.They are not perfect..
The datasheet says that when its junction is at 25 degrees C its output voltage is typically 3.0V but it could be anywhere from 2.97V to 3.03V so yours are fine.