DATA SH EET
Product specification
File under Integrated Circuits, IC06 September 1993
INTEGRATED CIRCUITS
74HC/HCT245
Octal bus transceiver; 3-state
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
September 1993 2
Philips Semiconductors Product specification
Octal bus transceiver; 3-state 74HC/HCT245
FEATURES
•Octal bidirectional bus interface
•Non-inverting 3-state outputs
•Output capability: bus driver
•ICC category: MSI
GENERAL DESCRIPTIONS
The 74HC/HCT245 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 74HC/HCT245 are octal transceivers featuring
non-inverting 3-state bus compatible outputs in both send
and receive directions. The “245” features an output
enable (OE) input for easy cascading and a send/receive
(DIR) for direction control. OE controls the outputs so that
the buses are effectively isolated. The “245” is similar to
the “640” but has true (non-inverting) outputs.
QUICK REFERENCE DATA
GND = 0 V; Tamb =25°C; tr=t
f= 6 ns
Notes
1. CPD is used to determine the dynamic power dissipation (PD in µW):
PD=C
PD ×VCC2×fi+∑ (CL×VCC2×fo) where:
fi= input frequency in MHz
fo= output frequency in MHz
∑(CL×VCC2×fo) = sum of outputs
CL= output load capacitance in pF
VCC = supply voltage in V
2. For HC the condition is VI= GND to VCC
For HCT the condition is VI= GND to VCC −1.5 V
ORDERING INFORMATION
See
“74HC/HCT/HCU/HCMOS Logic Package Information”
.
SYMBOL PARAMETER CONDITIONS TYPICAL UNIT
HC HCT
tPHL/ tPLH propagation delay
An to Bn;B
n
to An
CL= 15 pF; VCC =5V 7 10 ns
C
Iinput capacitance 3.5 3.5 pF
CI/Oinput/output capacitance 10 10 pF
CPD power dissipation capacitance per transceiver notes 1 and 2 30 30 pF
September 1993 3
Philips Semiconductors Product specification
Octal bus transceiver; 3-state 74HC/HCT245
PIN DESCRIPTION
PIN NO. SYMBOL NAME AND FUNCTION
1 DIR direction control
2, 3, 4, 5, 6, 7, 8, 9 A0 to A7data inputs/outputs
10 GND ground (0 V)
18, 17, 16, 15, 14, 13, 12, 11 B0 to B7data inputs/outputs
19 OE output enable input (active LOW)
20 VCC positive supply voltage
Fig.1 Pin configuration. Fig.2 Logic symbol. Fig.3 IEC logic symbol.
September 1993 4
Philips Semiconductors Product specification
Octal bus transceiver; 3-state 74HC/HCT245
Fig.4 Functional diagram.
FUNCTION TABLE
Notes
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
Z = high impedance OFF-state
INPUTS INPUTS/OUTPUTS
OE DIR AnBn
L
L
H
L
H
X
A=B
inputs
Z
inputs
B=A
Z
September 1993 5
Philips Semiconductors Product specification
Octal bus transceiver; 3-state 74HC/HCT245
DC CHARACTERISTICS FOR 74HC
For the DC characteristics see
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
.
Output capability: bus driver
ICC category: MSI
AC CHARACTERISTICS FOR 74HC
GND = 0 V; tr=t
f= 6 ns; CL=50pF
SYMBOL PARAMETER
Tamb (°C)
UNIT
TEST CONDITIONS
74HC VCC
(V) WAVEFORMS
+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
tPHL/ tPLH propagation delay
An to Bn;
Bn to An
25
9
7
90
18
15
115
23
20
135
27
23
ns 2.0
4.5
6.0
Fig.5
tPZH/ tPZL 3-state output enable time
OE to An;
OE to Bn
signalname DIR
30
11
9
150
30
26
190
38
33
225
45
38 ns 2.0
4.5
6.0 Fig.6
tPHZ/ tPLZ 3-state output disable time
OE to An;
OE to Bn
signalname DIR
41
15
12
150
30
26
190
38
33
225
45
38
ns 2.0
4.5
6.0 Fig.6
tTHL/ tTLH output transition time 14
5
4
60
12
10
75
15
13
90
18
15
ns 2.0
4.5
6.0
Fig.5
September 1993 6
Philips Semiconductors Product specification
Octal bus transceiver; 3-state 74HC/HCT245
DC CHARACTERISTICS FOR 74HCT
For the DC characteristics see
“74HC/HCT/HCU/HCMOS Logic Family Specifications”
.
Output capability: bus driver
ICC category: MSI
Note to HCT types
The value of additional quiescent supply current (∆ICC) for a unit load of 1 is given in the family specifications.
To determine ∆ICC per input, multiply this value by the unit load coefficient shown in the table below.
AC CHARACTERISTICS FOR 74HCT
GND = 0 V; tr=t
f= 6 ns; CL=50pF
INPUT UNIT LOAD COEFFICIENT
An
Bn
OE
DIR
0.40
0.40
1.50
0.90
SYMBOL PARAMETER
Tamb (°C)
UNIT
TEST CONDITIONS
74HCT VCC
(V) WAVEFORMS
+25 −40 to +85 −40 to +125
min. typ. max. min. max. min. max.
tPHL/ tPLH propagation delay
An to Bn;
Bn to An
12 22 28 33 ns 4.5 Fig.5
tPZH/ tPZL 3-state output enable time
OE to An;
OE to Bn
signalname DIR
16 30 38 45 ns 4.5 Fig.6
tPHZ/ tPLZ 3-state output disable time
OE to An;
OE to Bn
signalname DIR
16 30 38 45 ns 4.5 Fig.6
tTHL/ tTLH output transition time 5 12 15 18 ns 4.5 Fig.5
September 1993 7
Philips Semiconductors Product specification
Octal bus transceiver; 3-state 74HC/HCT245
AC WAVEFORMS
PACKAGE OUTLINES
See
“74HC/HCT/HCU/HCMOS Logic Package Outlines”
.
Fig.5 Waveforms showing the input (An, Bn) to output (Bn, An) propagation delays and the output transition times.
(1) HC : VM= 50%; VI= GND to VCC.
HCT : VM= 1.3 V; VI= GND to 3 V.
Fig.6 Waveforms showing the 3-state enable and disable times.
(1) HC : VM= 50%; VI= GND to VCC.
HCT : VM= 1.3 V; VI= GND to 3 V.
