Application Information

The LPV531 is an extremely versatile operational amplifier

because performance and power consumption can be ad-

justed during operation. This provides a method to dynami-

cally optimize the supply current, the bandwidth and the

output short circuit current in the application. The power level

can be set by the current drawn from the I

to the application performance requirements.

CIRCUIT TOPOLOGY

As shown in Figure 1, the LPV531 contains two internal bias

reference generators that deliver a reference current (I

to the amplifier core. The programmable bias generator gen-

erates a 110 mV reference voltage (V

voltage is converted into a programmable reference current

(I

resistor (R

added to the output current from the low power bias genera-

tor (I

zero and the I

that in this mode the power supply current is below 1 µA. In

this 1 µA power mode, the LPV531 is functional but perfor-

mance over the full temperature range is not guaranteed.

The 1 µA power mode operation is only recommended for

applications with a temperature range between 0 and 70˚C.

POWER MODE CONTROL

To illustrate typical configurations three possible solutions to

control the power mode(s) of the LPV531 will be described.

1. Single Power Mode

If the application requires one single power mode for the

LPV531, then the easiest way to achieve this is to connect a

resistor (R

internal circuitry, R

the I

Ω

internal

series

resistor

(R

which

is

biased

at

V

For a desired supply current, bandwidth, short circuit current,

or load resistance, the required value of R

lated using the equations in the section “DETERMINING

THE I

20132337

FIGURE 1. Simplified Schematic

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FIGURE 2. Single Power Mode

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