TLE2682 Datasheet, PDF (10/49 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
PARAMETER MEASUREMENT INFORMATION
typical values
Typical values presented in this data sheet represent the median (50% point) of device parametric performance.
input bias and offset current
At the picoampere bias-current level typical of the TLE2682, accurate measurement of the bias currents
becomes difficult. Not only does this measurement require a picoammeter, but test socket leakages can easily
exceed the actual device bias currents. To accurately measure these small currents, Texas Instruments uses
a two-step process. The socket leakage is measured using picoammeters with bias voltages applied, but with
no device in the socket. The device is then inserted in the socket, and a second test is performed that measures
both the socket leakage and the device input bias current (see Figure 6). The two measurements are then
subtracted algebraically to determine the bias current of the device.
1N4933
COUT
+
RL
0.1 µF
1
1 OUT
2
1 IN −
3
1 IN +
4
VCC _−
5
VOUT
6
VREF
7
OSC
8
VIN
TLE2682
16
VCC +
15
2 OUT
14
2 IN −
13
2 IN +
12
CAP −
11
GND
10
CAP +
9
FB/SD
0.1 µF
RL
5V
+
2 µF
CIN
+
Figure 6. Bias-Current Test Circuit
10
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
• POST OFFICE BOX 1443 HOUSTON, TEXAS 77251−1443