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M74HC651 Datasheet, PDF (1/12 Pages) STMicroelectronics – HC652 OCTAL BUS TRANSCEIVER/REGISTER 3-STATE HC651 OCTAL BUS TRANSCEIVER/REGISTER 3-STATE, INV.
M74HC651
M74HC652
HC651 OCTAL BUS TRANSCEIVER/REGISTER (3-STATE, INV.)
HC652 OCTAL BUS TRANSCEIVER/REGISTER (3-STATE)
. HIGH SPEED
fMAX = 73 MHz (TYP.) AT VCC = 5V
. LOW POWER DISSIPATION
ICC = 4 µA (MAX.) AT TA = 25 °C
. HIGH NOISE IMMUNITY
VNIH = VNIL = 28 % VCC (MIN.)
. OUTPUT DRIVE CAPABILITY
15 LSTTL LOADS
. SYMMETRICAL OUTPUT IMPEDANCE
IOH = IOL = 6 mA (mIN.)
. BALANCED PROPAGATION DELAYS
tPLH = tPHL
. WIDE OPERATING VOLTAGE RANGE
VCC (OPR) = 2 V TO 6 V
. PIN AND FUNCTION COMPATIBLE
WITH 54/74LS651/652
DESCRIPTION
B1R
(Plastic Package)
M1R
(Micro Package)
ORDER CODES :
M74HCXXXM1R M74HCXXXB1R
PIN CONNECTIONS (top view)
M74HC651/652 are high speed CMOS OCTAL
BUS TRANSCEIVERS AND REGISTERS (3-
STATE), fabricated in silicon gate C2MOS technol-
ogy. They have the same high speed performance
of LSTTL combined with true CMOS low power con-
sumption. These devices consist of bus transceiver
circuits, D-type flip-flops, and control circuitry ar-
ranged for multiplexed transmission of data directly
from the input bus or from the internal storage reg-
isters. Enable GAB and GBA are provided to control
the transceiver functions.
Select AB and Select BA control pins are provided
to select whether real-time or stored data is trans-
fered. A low input level selects real-time data, and
a high selects stored data.
Data on the A or B bus, or both, can be stored in the
internal D flip-flops by low-to-high transitions at the
appropriate clock pins (CLOCK AB or CLOCK BA)
regardless of the select or enable control pins. When
select AB and select BA are in the real-time transfer
mode, it is also possible to store data without using
the internal D-type flip-flops by simultaneously en-
abling GAB and GBA. In this configuration each out-
put reinforces its input. Thus, when all other data
sources to the two sets of bus lines are at high im-
pedance, each set of bus lines will remain at its last
state. All inputs are equipped with protection circuits
against static discharge and transient excess volt-
age.
INPUT AND OUTPUT EQUIVALENT CIRCUIT
GAB, GAB, CAB,
A, B
SAB, SBA, CBA
October 1993
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