TLE2662 Datasheet, PDF (24/40 Pages) Texas Instruments – DUAL uPOWER JFET-INPUT OPERATIONAL AMPLIFIER WITH SWITCHED-CAPACITOR VOLTAGE CONVERTER

TLE2662
DUAL µPOWER JFET-INPUT OPERATIONAL AMPLIFIER
WITH SWITCHED-CAPACITOR VOLTAGE CONVERTER
SLOS118B – DECEMBER 1992 – REVISED AUGUST 1994
APPLICATION INFORMATION
amplifier section
input characteristics
The TLE2662 is specified with a minimum and a maximum input voltage that if exceeded at either input, could
cause the device to malfunction.
Because of the extremely high input impedance and resulting low bias-current requirements, the TLE2662
operational amplifier section is well suited for low-level signal processing; however, leakage currents on printed-
circuit boards and sockets can easily exceed bias-current requirements and cause degradation in system
performance. It is a good practice to include guard rings around inputs (see Figure 47). These guards should
be driven from a low-impedance source at the same voltage level as the common-mode input.
The inputs of any unused amplifiers should be tied to ground to avoid possible oscillation.
VI
+
–
VI
VO
+
+
VO
VO
–
VI
–
switched-capacitor section
SCREF
Figure 47. Use of Guard Rings
VCC
FB/SD
OSC
REF
2.5 V
R
+
–
Q
OSC
Q
R
Drive
CAP +
CIN†
CAP –
Drive
Drive
Drive
GND
COUT†
SCOUT
† _{External capacitors}
Figure 48. Functional Block Diagram for Switched-Capacitor Block Only
24
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265