R

S

OPA322

V+

V

IN

V

OUT

I

10mA,Max

OVERLOAD

4

3

2

1

0

1

2

3

4

-

-

-

-

-500

1000

Time( s)

m

-250

0

750

250

500

V

OUT

V

IN

V = 2.5V

±

S

OPA322, OPA322S

OPA2322, OPA2322S

OPA4322, OPA4322S

www.ti.com

SBOS538A

– JANUARY 2011 – REVISED MAY 2011

APPLICATION INFORMATION

OPERATING VOLTAGE

The OPA322 series op amps are unity-gain stable and can operate on a single-supply voltage (1.8 V to 5.5 V), or

a split-supply voltage (

±0.9 V to ±2.75 V), making them highly versatile and easy to use. The power-supply pins

should have local bypass ceramic capacitors (typically 0.001

μF to 0.1 μF). These amplifiers are fully specified

from +1.8 V to +5.5 V and over the extended temperature range of

–40°C to +125°C. Parameters that can exhibit

variance with regard to operating voltage or temperature are presented in the Typical Characteristics.

INPUT AND ESD PROTECTION

The OPA322 incorporates internal electrostatic discharge (ESD) protection circuits on all pins. In the case of

input and output pins, this protection primarily consists of current-steering diodes connected between the input

and power-supply pins. These ESD protection diodes also provide in-circuit input overdrive protection, as long as

the current is limited to 10 mA as stated in the Absolute Maximum Ratings table. Many input signals are

inherently current-limited to less than 10 mA; therefore, a limiting resistor is not required. Figure 25 shows how a

contributes thermal noise at the amplifier input and the value should be kept to the minimum in noise-sensitive

applications.

Figure 25. Input Current Protection

PHASE REVERSAL

The OPA322 op amps are designed to be immune to phase reversal when the input pins exceed the supply

voltages, therefore providing further in-system stability and predictability. Figure 26 shows the input voltage

exceeding the supply voltage without any phase reversal.

Figure 26. No Phase Reversal

Copyright

© 2011, Texas Instruments Incorporated

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