V

OUT

R = 10kW

P

500 A

m

OPA363

OPA364

V

IN

V+ = +5V

Op Amp

Negative

Supply

Grounded

-V = 5V

-

(Additional

Negative Supply)

5kW

OPAx363

10mA max

V+

V

IN

V

OUT

I

OVERLOAD

OPA363, OPA2363

OPA364, OPA2364, OPA4364

www.ti.com

SBOS259C – SEPTEMBER 2002 – REVISED MAY 2013

INPUT AND ESD PROTECTION

All OPA363 and OPA364 pins are static protected with internal ESD protection diodes tied to the supplies. These

diodes will provide overdrive protection if the current is externally limited to 10mA, as stated in the absolute

maximum ratings and shown in Figure 24.

Figure 24. Input Current Protection

ACHIEVING OUTPUT SWING TO THE OP AMP’S NEGATIVE RAIL

Some applications require an accurate output voltage swing from 0V to a positive full-scale voltage. A good

single supply op amp may be able to swing within a few mV of single supply ground, but as the output is driven

toward 0V, the output stage of the amplifier will prevent the output from reaching the negative supply rail of the

amplifier.

The output of the OPA363 or OPA364 can be made to swing to ground, or slightly below, on a single supply

power source. To do so requires use of another resistor and an additional, more negative power supply than the

op amp’s negative supply. A pulldown resistor may be connected between the output and the additional negative

supply to pull the output down below the value that the output would otherwise achieve as shown in Figure 25.

Figure 25. OPA363 and OPA364 Swing to Ground

This technique will not work with all op amps. The output stage of the OPA363 and OPA364 allows the output

voltage to be pulled below that of most op amps, if approximately 500

μA is maintained through the output stage.

To calculate the appropriate value load resistor and negative supply, RL = –V/500

μA. The OPA363 and OPA364

have been characterized to perform well under the described conditions, maintaining excellent accuracy down to

0V and as low as –10mV. Limiting and nonlinearity occur below –10mV, with linearity returning as the output is

again driven above –10mV.

Copyright © 2002–2013, Texas Instruments Incorporated

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Product Folder Links: OPA363 OPA2363 OPA364 OPA2364 OPA4364