74HC7245 Datasheet, PDF (2/7 Pages) NXP Semiconductors – Octal bus Schmitt-trigger transceiver; 3-state

Philips Semiconductors
Octal bus Schmitt-trigger transceiver;
3-state
Product specification
74HC/HCT7245
FEATURES
• Octal bidirectional bus interface
• Non-inverting 3-state outputs
• Output capability: bus driver
• I_CC category: MSI
• Schmitt-trigger action on all data
inputs
GENERAL DESCRIPTION
The 74HC/HCT7245 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/HCT7245 are octal
transceivers featuring non-inverting
3-state bus compatible outputs in
both send and receive directions. The
“7245” features an output enable
(OE) input for easy cascading and a
send/receive input (DIR) for direction
control. OE controls the outputs so
that the buses are effectively isolated.
The 74HC/HCT7245 have
Schmitt-trigger inputs. These inputs
are capable of transforming slowly
changing input signals into sharply
defined jitter-free output signals.
The “7245” is identical to the “245” but
has hysteresis on the data inputs.
FUNCTION TABLE
INPUTS
OE DIR
LL
LH
HX
INPUTS/OUTPUTS
A_n
A=B
inputs
Z
B_n
inputs
B=A
Z
Notes
1. H = HIGH voltage level
L = LOW voltage level
X = don’t care
Z = high impedance OFF-state
QUICK REFERENCE DATA
GND = 0 V; T_amb = 25 °C; t_r = t_f = 6 ns
SYMBOL PARAMETER
CONDITIONS
t_PHL/ t_PLH
C_I
C_I/O
C_PD
propagation delay A_n to B_n
input capacitance
input/output capacitance
power dissipation capacitance per transceiver
C_L = 15 pF; V_CC = 5 V
notes 1 and 2
Notes
1. C_PD is used to determine the dynamic power dissipation (P_D in µW):
P_D = C_PD × V_CC2 × f_i + ∑ (C_L × V_CC2 × f_o) where:
f_i = input frequency in MHz
f_o = output frequency in MHz
∑ (C_L × V_CC2 × f_o) = sum of outputs
C_L = output load capacitance in pF
V_CC = supply voltage in V
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
TYPICAL
HC HCT
8
12
3.5 3.5
10
10
40
40
UNIT
ns
pF
pF
pF
ORDERING INFORMATION
See “74HC/HCT/HCU/HCMOS Logic Package Information”.
December 1990
2