020170
Full Member level 4
When I Rail to Rail OPAMP designed, I found that some opamp output range is really rail to rail.
For example, BUF16820 & BUF16821 INL/DNL specification is like this.
In BUF16820, when VDD power is 18V, INL measure voltage is 17V. So voltage difference of rail(VDD) and amp's output is 1V.
Yes. BUF16820 is not REALLY rail to rail amp. It has 1V headroom voltage! It doesn't care whatever INL/DNL value between 18V and 17V or 1V and GND.
In BUF16821, however, any condition is not described in INL/DNL specification. Suprisingly, it's INL/DNL specification covers all output range, includes rail to rail.
My question is below.
1. What is the difference BUF16821 opamp and BUF16820 opamp?
2. Regarding the INL specification, what should I concern to guarantee the full range of the output?
Thanks!
For example, BUF16820 & BUF16821 INL/DNL specification is like this.
In BUF16820, when VDD power is 18V, INL measure voltage is 17V. So voltage difference of rail(VDD) and amp's output is 1V.
Yes. BUF16820 is not REALLY rail to rail amp. It has 1V headroom voltage! It doesn't care whatever INL/DNL value between 18V and 17V or 1V and GND.
In BUF16821, however, any condition is not described in INL/DNL specification. Suprisingly, it's INL/DNL specification covers all output range, includes rail to rail.
My question is below.
1. What is the difference BUF16821 opamp and BUF16820 opamp?
2. Regarding the INL specification, what should I concern to guarantee the full range of the output?
Thanks!
Last edited:
