SN54HCT646, SN74HCT646

OCTAL BUS TRANSCEIVERS AND REGISTERS

WITH 3-STATE OUTPUTS

SCLS178C – MARCH 1984 – REVISED MARCH 2003

4

POST OFFICE BOX 655303

logic diagram (positive logic)

A1

B1

One of Eight Channels

SAB

CLKAB

SBA

CLKBA

DIR

OE

To Seven Other Channels

21

3

23

22

1

2

4

20

1D

C1

1D

C1

Pin numbers shown are for the DW, JT, NT, and W packages.

–0.5 V to 7 V

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

±20 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

±20 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

±35 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

±70 mA

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Package thermal impedance,

46

°C/W

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(see Note 3): NT package

67

°C/W

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

–65

°C to 150°C

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

† Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and

functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not

implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

NOTES:

1. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.

2. The package thermal impedance is calculated in accordance with JESD 51-7.

3. The package thermal impedance is calculated in accordance with JESD 51-3.