Datasheet
SN74CBT3244
OCTAL FET BUS SWITCH
SCDS001N − NOVEMBER 1992 − REVISED SEPTEMBER 2003
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
description/ordering information (continued)
The SN74CBT3244 provides eight bits of high-speed TTL-compatible bus switching. The SOIC, SSOP, TSSOP,
and TVSOP packages provide a standard ’244 device pinout. The low on-state resistance of the switch allows
connections to be made with minimal propagation delay.
The device is organized as two 4-bit low-impedance switches with separate output-enable (OE
) inputs. When
OE
is low, the switch is on, and data can flow from port A to port B, or vice versa. When OE is high, the switch
is open, and the high-impedance state exists between the two ports.
To ensure the high-impedance state during power up or power down, OE
should be tied to V
CC
through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
FUNCTION TABLE
(each 4-bit bus switch)
INPUT
OE
FUNCTION
L A port = B port
H Disconnect
logic diagram (positive logic)
1OE
1A1
1A4
1B1
1B4
2
8
1
18
12
2OE
2A1
2A4
2B1
2B4
11
17
19
9
3
Pin numbers shown are for the DB, DBQ, DGV, DW, RGY, and PW packages.