TLE2682 Datasheet, PDF (30/49 Pages) Texas Instruments – HIGH-SPEED JFET-INPUT DUAL OPERATIONAL AMPLIFIER WITH SWITCHED-CAPACITOR VOLTAGE CONVERTER

TLE2682
HIGHĆSPEED JFETĆINPUT DUAL OPERATIONAL AMPLIFIER
WITH SWITCHEDĆCAPACITOR VOLTAGE CONVERTER
SLOS127 − JUNE 1993
APPLICATION INFORMATION
amplifier section
input characteristics
The TLE2682 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 TLE2682
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 70). These guards should
be driven from a low-impedance source at the same voltage level as the common-mode input.
Unused amplifiers should be connected as grounded voltage followers to avoid potential oscillation.
VI
+
−
VI
VO
+
+
VO
VO
−
VI
−
Figure 70. Use of Guard Rings
switched-capacitor section
Figure 71 shows the functional block diagram for the switched-capacitor block only.
VREF
VCC
FB/SD
OSC
REF
2.5 V
R
+
−
Q
OSC
Q
R
Drive
CAP +
CAP −
Drive
CIN†
Drive
Drive
GND
COUT†
VOUT
† _{External capacitors}
Figure 71. Functional Block Diagram for Switched-Capacitor Block Only
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