AS2376

Document number: DS45193 Rev. 1 - 2

10 of 13

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September 2022

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AS2376

Application Information

Overview

The

DIODES™ AS2376 combines low offset (25μV maximum) and 5.5-MHz bandwidth for a wide variety of filtering and control applications.

Many op amps use chopper stabilization to achieve low offset voltage but this normally comes with a restriction of bandwidth to less than 500kHz.

The offset of the AS2376 is addressed by using post package trim allowing for the retention of significant bandwidth.

Stability considerations when driving capacitive loads

Operational amplifiers are prone to oscillation when required to drive large capacitive loads. The AS2376 is capable of driving a 250 picofarad load

at unity gain. Larger loads will require the insertion of a nulling resistor (denoted as RS) in series with the load capacitor. The suggested nulling

resistor value is 10

Ω to 20Ω. This addition will introduce a small error but is negligible in most applications.

Vin

AS2376

0.01µF

V-

V+

In-

In+

Circuit for Driving Large Capacitive Loads

Vout

RS

RL

CL

10

Ω to

20Ω

Offset voltage as input common mode approaches V+

The AS236 has an input circuitry configuration that is common to most rail to rail input operational amplifiers. At the low end of the common mode

input voltage range, the input signals are processed by a differential pair of PMOS transistors. This portion of the circuit is precision adjusted with

post package trim allowing the offset to be in the microvolts range. As the input common mode voltage approaches approximately one volt less

than the positive supply, the inputs are transitioned to a second differential pair of NMOS transistors. This portion of the op amp has an offset

voltage similar to a conventional op amp. As noted in the heading of the Electrical Characteristics Section, the precision offset voltage is optimized

at a common mode of one half of the supply voltage. This conceptual chart depicts the approximate best case of extending the precision common

mode area by using the device at 5.5V supply.

0

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

Input Common Mode Voltage (V) V+ = 5.5V

-0.5

0

-1

-2

-3

3

2

1

Offset Voltage over Common Mode Voltage Range