1 Features

• Output voltage translation tracks VCC

• Supports mixed-mode signal operation on all data

I/O ports

– 5V input down to 3.3V output level shift with

3.3V VCC

– 5V/3.3V input down to 2.5V output level shift

with 2.5V VCC

• 5V-tolerant I/Os with device powered up or

powered down

• Bidirectional data flow with near-zero propagation

delay

• Low ON-state resistance (ron) characteristics (ron =

5Ω typ)

• Low input/output capacitance minimizes loading

(Cio(OFF) = 5pF typ)

• Data and control inputs provide undershoot clamp

diodes

• Low power consumption (ICC = 20μA max)

• VCC operating range from 2.3V to 3.6V

• Data I/Os support 0V to 5V signaling levels (0.8V,

1.2V, 1.5V, 1.8V, 2.5V, 3.3V, 5V)

• Control inputs can be driven by TTL or 5V/3.3V

CMOS outputs

• Ioff supports partial-power-down mode operation

• Latch-up performance exceeds 250mA per JESD

17

• ESD performance tested per JESD 22

– 2000V human-body model (A114-B, Class II)

– 1000V charged-device model (C101)

2 Applications

• Supports digital applications:

– Level translation

– USB interface

– Memory interleaving

– Bus isolation

• Designed for low-power portable equipment

3 Description

The SN74CB3T3257 is a high-speed TTL-compatible

FET multiplexer/demultiplexer with low ON-state

resistance (ron), allowing for minimal propagation

delay. The device fully supports mixed-mode signal

operation on all data I/O ports by providing voltage

translation that tracks VCC. The SN74CB3T3257

supports systems using 5V TTL, 3.3V LVTTL, and

2.5V CMOS switching standards, as well as userdefined

switching levels.

This device is fully specified for partial-power-down

applications using Ioff. The Ioff feature verifies that

damaging current does not backflow through the

device when the device is powered down. The device

has isolation during power off.