SN74CBT3306C

DUAL FET BUS SWITCH

5V BUS SWITCH WITH 2V UNDERSHOOT PROTECTION

SCDS127A − SEPTEMBER 2003 − REVISED OCTOBER 2003

2

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

description/ordering information (continued)

This device is fully specified for partial-power-down applications using Ioff. The Ioff feature ensures that

damaging current will not backflow through the device when it is powered down. The device has isolation during

power off.

To ensure the high-impedance state during power up or power down, OE should be tied to VCC through a pullup

resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

FUNCTION TABLE

(each bus switch)

INPUT

INPUT/OUTPUT

FUNCTION

INPUT

OE

INPUT/OUTPUT

A

FUNCTION

L

B

A port = B port

H

Z

Disconnect

logic diagram (positive logic)

1A

1OE

SW

1B

2A

2OE

SW

2B

2

1

5

7

3

6

simplified schematic, each FET switch (SW)

A

EN†

B

† EN is the internal enable signal applied to the switch.

Undershoot

Protection Circuit