OPA - Operational Amplifiers for hardware developers and manufacturing
When RCal is hardware processed (not software configured) we consider using a lower offset OPA than LM324D (although we could calibrate and compansate in software).
I'm a bit confused, which is the order of preference for OPA now? Please review
- LT1882 ? best
- texas type OPA4277UA or lettle brother good
- texas type y ? still OK
- LM324D last chance (needs offset calibration at 2 temps)
We selected the 277 series from Texas.
Try to use it for pump and sensitive stuff (such as precise input mA diffamp) only.
- OPA2277 has 2 OPA-s in 8 pin SOIC while
- OPA4277UA has 4 OPA in 14 pin SOIC (LM324D pin compatible drop in replacement). Available in a week, a bit expensive though, costs more than 2 x atmega88-20 MHz
- [OPA4277.pdf] page 6: rail-2-rail properties are OK. +0.6V and Vss-1V at 5mA.
Dropped:
- [OPA2228] (texas) series 75uV offset, not rail2rail but it might work.
- LT1882 or LT1885 nice parts but where to get? Our distributor does not have any. linear.com has some webshop, that might work
MCP3208 serial ADC (SAR) substitute
- [TCL1543] 11 channels, 10 bit ADC with good cost and temperature range (whenever 8 of the MCP3208 is on the low side), the DB20 package is nice small footprint.
See also