INTEGRATED CIRCUITS
DATA SH EET
For a complete data sheet, please also download:
•The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications
•The IC06 74HC/HCT/HCU/HCMOS Logic Package Information
•The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT7540
Octal Schmitt trigger buffer/line
driver; 3-state; inverting
Product specification
Supersedes data of March 1988
File under Integrated Circuits, IC06
December 1990
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
3-state; inverting
FEATURES
• Inverting outputs
• Schmitt trigger action on all data inputs
• Output capability: bus driver
• ICC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT7540 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.
QUICK REFERENCE DATA
GND = 0 V; T
=25°C; tr=tf= 6 ns
amb
SYMBOL PARAMETER CONDITIONS
t
PHL
C
C
/ t
I
PD
propagation delay An to Y
PLH
n
input capacitance 3.5 3.5 pF
power dissipation capacitance per buffer notes 1 and 2 29 31 pF
The 74HC/HCT7540 are octal Schmitt trigger inverting
buffer/line drivers with 3-state outputs. The 3-state outputs
are controlled by the output enable inputs
A HIGH on OEn causes the outputs to assume a high
impedance OFF-state.
The Schmitt trigger action in the data inputs transforms
slowly changing input signals into sharply defined
jitter-free output signals.
The “7540” is identical to the “540” but has hysteresis on
the data inputs.
CL= 15 pF; VCC=5 V 11 16 ns
74HC/HCT7540
OE1 and OE2.
TYPICAL
UNIT
HC HCT
Notes
1. C
is used to determine the dynamic power dissipation (PD in µW):
PD
PD=CPD× V
2
× fi+∑(CL× V
CC
2
× fo) where:
CC
fi= input frequency in MHz
fo= output frequency in MHz
∑ (CL× V
2
× fo) = sum of outputs
CC
CL= output load capacitance in pF
VCC= supply voltage in V
2. For HC the condition is VI= GND to V
CC
For HCT the condition is VI= GND to VCC− 1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”
.
December 1990 2
Philips Semiconductors Product specification
Octal Schmitt trigger buffer/line driver;
3-state; inverting
PIN DESCRIPTION
PIN NO. SYMBOL NAME AND FUNCTION
1, 19
2, 3, 4, 5, 6, 7, 8, 9 A
10 GND ground (0 V)
18, 17, 16, 15, 14, 13, 12, 11
20 V
OE1, OE
to A
0
Y0 to Y
CC
2
7
7
output enable inputs (active LOW)
data inputs
bus outputs
positive supply voltage
74HC/HCT7540
Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol.
December 1990 3