Hi, I'm working out the early stages for an amplifier. I've been looking at DAC modules and op-amps on RS and it seems that the offsets can be so low that I don't need to worry about trimming even down to 16bit res.
For example, this 16bit resistor string DAC is £3 from rs and it makes no mention of V offset but if my understanding of the resistor string method is correct, any zero-signal error will be negligible.
And this precision op-amp has rail-to-rail operation with <8uV offset.
By my calcs, for a DAC input of 0x0001 the DAC output voltage will be 2V/2^16 = 30uV. So worse case scenario the op-amp will introduce 25% LSB error, but in reality it'll probably be much less than this, and the temperature drift is minimal too.
So I can just plug the output of the DAC into the op-amp in an inverting configuration and I'm away. Is it really that simple?
For example, this 16bit resistor string DAC is £3 from rs and it makes no mention of V offset but if my understanding of the resistor string method is correct, any zero-signal error will be negligible.
And this precision op-amp has rail-to-rail operation with <8uV offset.
By my calcs, for a DAC input of 0x0001 the DAC output voltage will be 2V/2^16 = 30uV. So worse case scenario the op-amp will introduce 25% LSB error, but in reality it'll probably be much less than this, and the temperature drift is minimal too.
So I can just plug the output of the DAC into the op-amp in an inverting configuration and I'm away. Is it really that simple?
