1FEATURES

• Qualified for Automotive Applications

• Output Voltage Translation Tracks VCC

• Supports Mixed-Mode Signal Operation on All

Data I/O Ports

– 5-V Input Down to 3.3-V Output Level Shift

With 3.3-V VCC

– 5-V/3.3-V Input Down to 2.5-V Output Level

Shift With 2.5-V VCC

• 5-V-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 = 5 Ω Typ)

• Low Input/Output Capacitance Minimizes

Loading (Cio(OFF) = 5 pF Typ)

• Data and Control Inputs Provide Undershoot

Clamp Diodes

• Low Power Consumption

(ICC = 20 μA Max)

• VCC Operating Range From 2.3 V to 3.6 V

• Data I/Os Support 0- to 5-V Signaling Levels

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

• Control Inputs Can Be Driven by TTL or

5-V/3.3-V CMOS Outputs

• Ioff Supports Partial-Power-Down Mode

Operation

• Supports Digital Applications: Level

Translation, USB Interface, Bus Isolation

• Ideal for Low-Power Portable Equipment

DESCRIPTION

The SN74CB3T1G125-Q1 is a high-speed TTL-compatible FET bus switch 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 SN74CB3T1G125-Q1 supports systems using 5-V

TTL, 3.3-V LVTTL, and 2.5-V CMOS switching standards, as well as user-defined switching levels (see Figure 1).

The SN74CB3T1G125-Q1 is a 1-bit bus switch with a single ouput-enable (OE) input. When OE is low, the bus

switch is ON, and the A port is connected to the B port, allowing bidirectional data flow between ports. When OE

is high, the bus switch is OFF, and a high-impedance state exists between the A and B ports.

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.