Document
TLE2662 DUAL µPOWER JFET-INPUT OPERATIONAL AMPLIFIER
WITH SWITCHED-CAPACITOR VOLTAGE CONVERTER
SLOS118B – DECEMBER 1992 – REVISED AUGUST 1994
D Single-Supply Operation With Rail-to-Rail
Inputs
D VOL = 0.000 V While Sinking 25 mA D Wide VCC Range . . . 3.5 V to 15 V D SCOUT Supplies up to 100 mA for External
Loads
D Shutdown Mode D External 2.5-V Voltage Reference Available
description
DW PACKAGE (TOP VIEW)
1OUT 1 1IN – 2 1IN + 3 VCC – 4 SCOUT 5 SCREF 6 OSC 7 SCIN 8
16 VCC + 15 2OUT 14 2IN – 13 2IN + 12 CAP – 11 GND 10 CAP + 9 FB/SD
The TLE2662 offers the advantages of JFET-input operational amplifiers and rail-to-rail commonmode 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 switchedcapacitor 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).
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.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright © 1994, Texas Instruments Incorporated 1
TLE2662 DUAL µPOWER JFET-INPUT OPERATIONAL AMPLIFIER WITH SWITCHED-CAPACITOR VOLTAGE CONVERTER
SLOS118B – DECEMBER 1992 – REVISED AUGUST 1994
functional block diagram
1 1OUT 1IN – 2 1IN + 3 VCC – 4 SCOUT 5
6 SCREF
7 OSC SCIN 8
Amplifier Block
_
+
_
+
SwitchedCapacitor
Block
16 VCC + 15 2OUT 14 2IN – 13 2IN + 12 CAP – 11 GND 10 CAP + 9 FB/SD
ACTUAL DEVICE COMPONENT COUNT
AMPLIFIER BLOCK
SWITCHEDCAPACITOR BLOCK
Transistors 42 Transistors 71
Resistors
9 Resistors
44
Diodes
3 Diodes
2
Capacitors
2 Capacitors
5
2
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TLE2662 DUAL µPOWER JFET-INPUT OPERATIONAL AMPLIFIER
WITH SWITCHED-CAPACITOR VOLTAGE CONVERTER
SLOS118B – DECEMBER 1992 – REVISED AUGUST 1994
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)†
Supply voltage, SCIN (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 V Supply voltage, VCC + (see Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..