Datasheet

December 1990 2
Philips Semiconductors Product specification
Quad buffer/line driver; 3-state 74HC/HCT126
FEATURES
• Output capability: bus driver
• I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT126 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL).
They are specified in compliance with JEDEC standard no. 7A.
The HC/HCT126 are four non-inverting buffer/line drivers with 3-state outputs. The 3-state outputs (nY) are controlled by
the output enable input (nOE). A LOW at nOE causes the outputs to assume a HIGH impedance OFF-state.
The “126” is identical to the “125” but has active HIGH enable inputs.
QUICK REFERENCE DATA
GND = 0 V; T
amb
= 25 °C; t
r
= t
f
= 6 ns
Notes
1. C
PD
is used to determine the dynamic power dissipation (P
D
in µW):
P
D
= C
PD
× V
CC
2
× f
i
+ ∑ (C
L
× V
CC
2
× f
o
) where:
f
i
= input frequency in MHz
f
o
= output frequency in MHz
C
L
= output load capacitance in pF
V
CC
= supply voltage in V
∑ (C
L
× V
CC
2
× f
o
) = sum of outputs
2. For HC the condition is V
I
= GND to V
CC
For HCT the condition is V
I
= GND to V
CC
− 1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information” .
SYMBOL PARAMETER CONDITIONS
TYPICAL
UNIT
HC HCT
t
PHL
/ t
PLH
propagation delay nA to nY C
L
= 15 pF; V
CC
= 5 V 9 11 ns
C
I
input capacitance 3.5 3.5 pF
C
PD
power dissipation capacitance per buffer notes 1 and 2 23 24 pF