TLV2322, TLV2322Y, TLV2324, TLV2324Y

LinCMOS

™ LOW-VOLTAGE LOW-POWER

OPERATIONAL AMPLIFIERS

SLOS187 – FEBRUARY 1997

26

POST OFFICE BOX 655303

APPLICATION INFORMATION

input characteristics (continued)

–

+

–

+

–

+

(a) NONINVERTING AMPLIFIER

(b) INVERTING AMPLIFIER

(c) UNITY-GAIN AMPLIFIER

Vi

VI

VI

VO

VO

VO

Figure 42. Guard-Ring Schemes

noise performance

The noise specifications in operational amplifier circuits are greatly dependent on the current in the first-stage

differential amplifier. The low input bias-current requirements of the TLV232x result in a very low noise current,

which is insignificant in most applications. This feature makes the device especially favorable over bipolar

devices when using values of circuit impedance greater than 50 k

Ω, since bipolar devices exhibit greater noise

currents.

feedback

Operational amplifier circuits nearly always

employ feedback, and since feedback is the first

prerequisite for oscillation, caution is appropriate.

Most oscillation problems result from driving

capacitive

loads

and

ignoring

stray

input

capacitance. A small-value capacitor connected

in parallel with the feedback resistor is an effective

remedy (see Figure 43). The value of this

capacitor is optimized empirically.

electrostatic-discharge protection

The

TLV232x

incorporates

an

internal

electrostatic-discharge (ESD)-protection circuit

that prevents functional failures at voltages up to 2000 V as tested under MIL-PRF-38535, Method 3015.2. Care

should be exercised, however, when handling these devices as exposure to ESD can result in the degradation

of the device parametric performance. The protection circuit also causes the input bias currents to be

temperature dependent and have the characteristics of a reverse-biased diode.

latch-up

Because CMOS devices are susceptible to latch-up due to their inherent parasitic thyristors, the TLV232x inputs

and outputs are designed to withstand – 100-mA surge currents without sustaining latch-up; however,

techniques should be used to reduce the chance of latch-up whenever possible. Internal-protection diodes

should not by design be forward biased. Applied input and output voltage should not exceed the supply voltage

–

+

Figure 43. Compensation for Input Capacitance