| ??? 05/28/08 16:54 Read: times |
#155229 - buffer op-amp Responding to: ???'s previous message |
Raghunathan said:
Assuming I am going to use Op-Amps then will the following be the way to do it?
- I interpose a unity gain buffer with ( OP-07 ?) between the V-Out and the ADC input pin of the MCU. - Similarly I interpose another unity gain buufer between the V-Ref point in the circuit and the V_ref output of the MCU. Watch the op-amp supply rails. You need to use a "rail-to-rail" device whose inputs and output can swing to either rail. If you choose to power the op-amp from +3.3V and ground (which is reasonable) you need to make sure your op-amp output can actually swing to ground. The OP-07 won't. The other option, of course, is to provide bipolar supplies (+/-5V will do ya fine) if you can deal with the added complexity. -a |
| Topic | Author | Date |
| ADC of Silabs MCU | 01/01/70 00:00 | |
| At best the SiLabs A/D.... | 01/01/70 00:00 | |
| A Simple Attenuator | 01/01/70 00:00 | |
| Tweaking... | 01/01/70 00:00 | |
| Further tweaking.. | 01/01/70 00:00 | |
| yes | 01/01/70 00:00 | |
| I had that coming.. | 01/01/70 00:00 | |
| Drop the Trim | 01/01/70 00:00 | |
| 100% practical with theory | 01/01/70 00:00 | |
| For your A/D Subsystem.... | 01/01/70 00:00 | |
| buffer op-amp | 01/01/70 00:00 | |
| Chosen Op-Amp : CA5420A | 01/01/70 00:00 | |
| Settling time? | 01/01/70 00:00 | |
| My signal is a slowly varying one | 01/01/70 00:00 | |
settling time | 01/01/70 00:00 | |
| internal reference specified from 2.36 to 2.48 V! | 01/01/70 00:00 | |
| do not calibrate if you can avoid it | 01/01/70 00:00 |