TLC082-Q1 Datasheet, PDF (16/31 Pages) Texas Instruments – WIDE-BANDWIDTH HIGH-OUTPUT-DRIVE SINGLE-SUPPLY OPERATIONAL AMPLIFIERS

TLC080-Q1, TLC081-Q1
TLC082-Q1, TLC083-Q1
TLC084-Q1, TLC085-Q1
SLOS510B – SEPTEMBER 2006 – REVISED MAY 2011
APPLICATION INFORMATION
Input Offset Voltage Null Circuit
The TLC080 and TLC081 have an input offset nulling function (see Figure 48).
IN −
OUT
IN +
N2
N1
100 kΩ
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R1
V_{DD −}
A. R1 = 5.6 kΩ for offset voltage adjustment of ±10 mV
R1 = 20 kΩ for offset voltage adjustment of ±3 mV
Figure 48. Input Offset Voltage Null Circuit
Driving a Capacitive Load
When the amplifier is configured in this manner, capacitive loading directly on the output decreases the device
phase margin, leading to high-frequency ringing or oscillations. Therefore, for capacitive loads of greater than 10
pF, it is recommended that a resistor be placed in series (R_NULL) with the output of the amplifier, as shown in
Figure 49. A minimum value of 20 Ω should work well for most applications.
R_F
R_G
Input
_
+
R_NULL
Output
C_LOAD
Figure 49. Driving a Capacitive Load
Offset Voltage
The output offset voltage, (V_OO) is the sum of the input offset voltage (V_IO) and both input bias currents (I_IB) times
the corresponding gains. The schematic and formula in Figure 50 can be used to calculate the output offset
voltage.
R_F
I_IB−
R_G
+
−
V_I
+
V_O
R_S
I_IB+
ǒ ǒ ǓǓ ǒ ǒ ǓǓ VOO + VIO
1)
RF
RG
" IIB₎ RS
1)
RF
RG
" IIB– RF
Figure 50. Output Offset Voltage Model
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