TLC254 Datasheet, PDF (20/21 Pages) Texas Instruments – LinCMOSE QUAD OPERATIONAL AMPLIFIERS

TLC254, TLC254A, TLC254B, TLC254Y, TLC25L4, TLC25L4A, TLC25L4B
TLC25L4Y, TLC25M4, TLC25M4A, TLC25M4B, TLC25M4Y
LinCMOS™ QUAD OPERATIONAL AMPLIFIERS
SLOS003F – JUNE 1983 – REVISED AUGUST 1994
APPLICATION INFORMATION
latch-up avoidance
Junction-isolated CMOS circuits have an inherent parasitic PNPN structure that can function as an SCR. Under
certain conditions, this SCR may be triggered into a low-impedance state, resulting in excessive supply current.
To avoid such conditions, no voltage greater than 0.3 V beyond the supply rails should be applied to any pin.
In general, the operational amplifiers supplies should be established simultaneously with, or before, application
of any input signals.
output stage considerations
The amplifier’s output stage consists of a source-follower-connected pullup transistor and an open-drain
pulldown transistor. The high-level output voltage (V_OH) is virtually independent of the I_DD selection and
increases with higher values of V_DD and reduced output loading. The low-level output voltage (V_OL) decreases
with reduced output current and higher input common-mode voltage. With no load, V_OL is essentially equal to
the potential of V_{DD –} /GND.
supply configurations
Even though the TLC25_4C series is are characterized for single-supply operation, they can be used effectively
in a split-supply configuration if the input common-mode voltage (V_ICR), output swing (V_OL and V_OH), and supply
voltage limits are not exceeded.
circuit layout precautions
Whenever extremely high circuit impedances are used, care must be exercised in layout, construction, board
cleanliness, and supply filtering to avoid hum and noise pickup as well as excessive dc leakages.
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