Operational amplifier having improved digitally adjusted null of

Details Operational amplifier having improved digitally adjusted null of Operational amplifier having improved digitally adjusted null of

1989-07-28

1990-06-12

Mullins, James B.

Amplifiers

With periodic switching input-output

330253, 330257, 330260, 330261, H03F 102, H03F 345

Patent

active

049336436

ABSTRACT:
An operational amplifier is provided having a null offset that may be digitally adjusted quickly and accurately. The operational amplifier includes a cascode current mirror in an output stage wherein a small portion of current in the cascode current mirror is diverted away into a digitally controlled current divider. The more current that is diverted away, the larger the differential voltage that is created between the inverting and noninverting inputs of the operational amplifier. The current is increased until the output of the operational amplifier switches from the positive supply voltage to the ground supply voltage or vise versa. Additionally, a compensation capacitor at the output of the operational amplifier is switched out of the circuit during adjustment to speed up the null offset adjustment. Because the current being adjusted is not directly at the inputs of the operational amplifier the common mode input range is not deteriorated.

REFERENCES:
patent: 4806875 (1989-02-01), Schaffer
patent: 4827222 (1989-05-01), Hester et al.

Affiliated with

Also associated with

Rating

Operational amplifier having improved digitally adjusted null of does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Operational amplifier having improved digitally adjusted null of, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Operational amplifier having improved digitally adjusted null of will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-619538