The TC74VHC138 is an advanced high speed CMOS 3-to-8
DECODER fabricated with silicon gate C²MOS technology.
It achieves the high speed operation similar to equivalent
Bipolar Schottky TTL while maintaining the CMOS low
power dissipation.
When the device is enabled, 3 Binary Select inputs (A, B and
C) determine which one of the outputs (TO-Y7) will go low.
When enable input G1 is held low or either G2A or G2B is
held high, decoding function is inhibited and all outputs go high.
G1, G2A, and G2B inputs are provided to ease cascade
connection and for use as an address decoder for memory systems.
An input protection circuit ensures that 0 to 7V can be
applied to the input pins without regard to the supply
voltage. This device can be used to interface 5V to 3V
systems and two supply systems such as battery back up.
This circuit prevents device destruction due to mismatched
supply and input voltages.

FEATURES:
• High Speed...
• Low Power Dissipation………………..
High Noise Immunity
• Power Down Protection is provided on all inputs.
Balanced Propagation Delays tpLH=tpHL
Wide Operating Voltage Range....Vcc (opr) = 2V~5.5V
• Pin and Function Compatible with 74ALS138
tpd 5./ns(typ.) at Vcc=5V
Icc-4A(Max.) at Ta -25°C
•VNIH=VNIL = 28% Vcc (Min.)