TLE2662

DUAL

µPOWER JFET-INPUT OPERATIONAL AMPLIFIER

WITH SWITCHED-CAPACITOR VOLTAGE CONVERTER

SLOS118B – DECEMBER 1992 – REVISED AUGUST 1994

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POST OFFICE BOX 655303

Inputs

Loads

description

The TLE2662 offers the advantages of JFET-input

operational amplifiers and rail-to-rail common-

mode input voltage range with the convenience of single-supply operation. By combining a switched-capacitor

voltage converter with a dual operational amplifier in a single package, Texas Instruments now gives circuit

designers new options for conditioning low-level signals in single-supply systems.

The TLE2662 features two low power, high-output drive JFET-input operational amplifiers with a switched-

capacitor building block. Using two external capacitors, the switched-capacitor network can be configured as

a voltage inverter, generating a negative supply voltage capable of sourcing up to 100 mA. This supply functions

not only as the amplifier negative rail but is also available to drive external circuitry. In this configuration, the

amplifier common-mode input voltage range extends from the positive rail to below ground, providing true

rail-to-rail inputs from a single supply. Furthermore, the outputs can swing to and below ground while sinking

over 25 mA. This feature was previously unavailable in operational amplifier circuits. The TLE2662 operational

amplifier section has output stages that can drive 100-

Ω loads to 2.5 V from a 5-V rail. With a 10-kΩ load, the

output swing extends to 3.5 V and can include the positive rail with a pullup resistor.

This operational amplifier offers the high slew rate, wide bandwidth, and high input impedance commonly

associated with JFET-input amplifiers, making the TLE2662 operational amplifier section suited for amplifying

fast signals without loading the signal source. When not sourcing or sinking current into a load, the amplifier

consumes only microamperes of supply current, thereby reducing the drain on and extending the life of the

power supply.

The TLE2662 features a shutdown pin (FB/SD), which can be used to disable the switched capacitor section.

When disabled, the voltage converter block draws less than 150

µA from the power supply. This feature,

combined with the operational amplifier’s low quiescent current, makes the TLE2662 a real power saver in the

standby mode.

The switched-capacitor building block also provides an on-board regulator; with the addition of an external

divider, a well-regulated output voltage is easily obtained. Additional filtering can be added to minimize switching

noise. The internal oscillator runs at a nominal frequency of 25 kHz. This can be synchronized to an external

clock signal or can be varied using an external capacitor. A 2.5-V reference is brought out to SCREF for use

with the on-board regulator or external circuitry.

The TLE2662 is characterized for operation over the industrial temperature range of – 40

°C to 85°C. This device

is available in a 16-pin wide-body surface-mount package.

AVAILABLE OPTION

PACKAGE

TA

SMALL OUTLINE

(DW)

–40

°C to 85°C

TLE2662IDW

The DW package is available taped and reeled. Add

the suffix R to the device type (i.e., TLE2662IDWR).

Copyright

© 1994, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

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1OUT

1IN –

1IN +

SCOUT

SCREF

OSC

SCIN

2OUT

2IN –

2IN +

CAP –

GND

CAP +

FB/SD

DW PACKAGE

(TOP VIEW)