1/16September 2004
■ 5V TOLERANT INPUTS AND OUTPUTS
■ HIGH SPEED:
t
PD
= 7.0 ns (MAX.) at V
CC
= 3V
■ POWER DOWN PROTECTION ON INPUTS
AND OUTPUTS
■ SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 24mA (MIN) at V
CC
= 3V
■ PCI BUS LEVELS GUARANTEED AT 24 mA
■ BALANCED PROPAGATION DELAYS:
t
PLH
≅ t
PHL
■ OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 2.0V to 3.6V (1.5V Data
Retention)
■ PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 646
■ LATCH-UP PERFORMANCE EXCEEDS
500mA (JESD 17)
■ ESD PERFORMANCE:
HBM > 2000V (MIL STD 883 method 3015);
MM > 200V
DESCRIPTION
The 74LCX646 is a low voltage CMOS OCTAL
BUS TRANSCEIVER AND REGISTER
(3-STATE) fabricated with sub-micron silicon gate
and double-layer metal wiring C
2
MOS technology.
It is ideal for low power and high speed 3.3V
applications; it can be interfaced to 5V signal
environment for both inputs and outputs.
This device consists of bus transceiver circuits
with 3 state, D-type flip-flops, and control circuitry
arranged for multiplexed transmission of data
directly from the input bus or from the internal
registers. Data on the A or B bus will be clocked
into register on the low to high transition of the
appropriate clock pin (Clock AB or Clock BA).
Enable (G
) and direction (DIR) pins are provided
to control the transceiver functions. In the
transceiver mode, data present at the
high-impedance port may be stored in either
register or in both. The select controls (Select AB
select BA) can multiplex stored and real time
(transparent mode) data. The direction control
determines which bus will receive data when
enable G
is active (low). In the isolation mode
74LCX646
LOW VOLT. CMOS OCTAL BUS TRANSCEIVER/REGISTER
WITH 5 VOLT TOLERANT INPUTS AND OUTPUTS(3-STATE)
Figure 1: Pin Connection And IEC Logic Symbols
Table 1: Order Codes
PACKAGE T & R
SOP 74LCX646RM13TR
TSSOP 74LCX646TTR
TSSOPSOP
Rev. 6
