TLC27L1 Datasheet, PDF (23/32 Pages) Texas Instruments – LinCMOSE LOW-POWER OPERATIONAL AMPLIFIERS

TLC27L1, TLC27L1A, TLC27L1B
LinCMOS™ LOW-POWER
OPERATIONAL AMPLIFIERS
SLOS154 – DECEMBER 1995
APPLICATION INFORMATION
single-supply operation (continuted)
OUT
Logic
Logic
Logic
Power
Supply
(a) COMMON SUPPLY RAILS
OUT
Logic
Logic
Logic
Power
Supply
(b) SEPARATE BYPASSED SUPPLY RAILS (preferred)
Figure 39. Common Versus Separate Supply Rails
input offset voltage nulling
The TLC27L1 offers external input-offset null control. Nulling of the input-offset voltage may be achieved by
adjusting a 25-kΩ potentiometer connected between the offset null terminals with the wiper connected as shown
in Figure 40. Total nulling may not be possible.
VDD
IN –
IN +
ÎÎÎÎÎ_N1 ÎÎÎÎÎ_{–+ 25}ÎÎÎÎÎ_kΩ ÎÎÎÎÎ_N2
OUT
IN –
IN +
N^{ÎÎÎÎÎ}1–+ ^{ÎÎÎÎÎ25kÎÎÎÎÎΩ ÎÎÎÎÎN2}
OUT
GND
(a) SINGLE SUPPLY
(b) SPLIT SUPPLY
Figure 40. Input Offset-Voltage Null Circuit
input characteristics
The TLC27L1 is specified with a minimum and a maximum input voltage that, if exceeded at either input, could
cause the device to malfunction. Exceeding this specified range is a common problem, especially in
single-supply operation. Note that the lower range limit includes the negative rail, while the upper range limit
is specified at V_DD – 1 V at T_A = 25°C and at V_DD – 1.5 V at all other temperatures.
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