5 kW

Device

10 mA max

+5 V

V

IN

V

OUT

I

OVERLOAD

Current-limiting resistor

required if input voltage

exceeds supply rails by

³ 0.3 V.

OPA317

OPA2317

OPA4317

www.ti.com

SBOS682A – MAY 2013 – REVISED JUNE 2013

APPLICATIONS INFORMATION

The OPA317, OPA2317, and OPA4317 are unity-gain stable, precision operational amplifiers free from

unexpected output and phase reversal. Proprietary Zerø-Drift circuitry gives the benefit of low input offset voltage

over time and temperature, as well as lowering the 1/f noise component. As a result of the high PSRR, these

devices work well in applications that run directly from battery power without regulation. The OPA317 family is

optimized for low-voltage, single-supply operation. These miniature, high-precision, low quiescent current

amplifiers offer high-impedance inputs that have a common-mode range 100 mV beyond the supplies, and a rail-

to-rail output that swings within 100 mV of the supplies under normal test conditions. The OPA317 series are

precision amplifiers for cost-sensitive applications.

OPERATING VOLTAGE

(±0.9 V) up to +5.5 V (±2.75 V).

CAUTION

Supply voltages greater than +7 V can permanently damage the device.

See the Absolute Maximum Ratings table. Key parameters that vary over the supply voltage or temperature

range are shown in the Typical Characteristics section of this data sheet.

INPUT VOLTAGE

The OPA317, OPA2317, and OPA4317 input common-mode voltage range extends 0.1 V beyond the supply

rails. The OPA317 is designed to cover the full range without the troublesome transition region found in some

other rail-to-rail amplifiers.

Typically, input bias current is about 200 pA; however, input voltages exceeding the power supplies can cause

excessive current to flow into or out of the input pins. Momentary voltages greater than the power supply can be

tolerated if the input current is limited to 10 mA. This limitation is easily accomplished with an input resistor, as

shown in Figure 18.

Figure 18. Input Current Protection

INPUT DIFFERENTIAL VOLTAGE

The typical input bias current of the OPA317 during normal operation is approximately 200 pA. In overdriven

conditions, the bias current can increase significantly (see Figure 17).The most common cause of an overdriven

condition occurs when the op amp is outside of the linear range of operation. When the output of the op amp is

driven to one of the supply rails, the feedback loop requirements cannot be satisfied and a differential input

voltage develops across the input pins. This differential input voltage results in activation of parasitic diodes

inside the front-end input chopping switches that combine with 10-k

Ω electromagnetic interference (EMI) filter

resistors to create the equivalent circuit shown in Figure 19. Note that the input bias current remains within

specification within the linear region.

Copyright © 2013, Texas Instruments Incorporated

Submit Documentation Feedback

9

Product Folder Links: OPA317 OPA2317 OPA4317