TLE2662 Datasheet, PDF (10/40 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
PARAMETER MEASUREMENT INFORMATION
10 kΩ
100 Ω
VI
VCC ₊
–
VO
+
VCC _–
CL
RL
(see Note A)
NOTE A: CL includes fixture capacitance.
Figure 3. Unity-Gain Bandwidth and Phase-Margin Test Circuit
amplifier input bias offset current
At the picoampere bias-current level typical of the TLE2662, accurate measurement of the amplifier’s bias
current 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 into the socket and a second test that measures both
the socket leakage and the device input bias current is performed. The two measurements are then subtracted
algebraically to determine the bias current of the device.
1N4933
COUT
+
RL
0.1 µF
1
1OUT
2
1IN –
3
1IN +
4
VCC _–
5
SCOUT
6
SCREF
7
OSC
8
SCIN
TLE2662
Figure 4. Test Circuit
16
VCC +
15
2OUT
14
2IN –
13
2IN +
12
CAP –
11
GND
10
CAP +
9
FB/SD
0.1 µF
RL
+
2 µF
CIN
+
10
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