FEATURES

· Member of the Texas Instruments Widebus™

Family

· 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 W Typ)

· Low Input/Output Capacitance Minimizes

Loading (Cio(OFF) = 9 pF Typ)

· Data and Control Inputs Provide Undershoot

Clamp Diodes

· Low Power Consumption (ICC = 70 mA Max)

· VCC Operating Range From 2.3 V to 3.6 V

· Data I/Os Support 0-V 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

· Latch-Up Performance Exceeds 250 mA Per

JESD 17

· ESD Performance Tested Per JESD 22

– 2000-V Human-Body Model(A114-B, Class II)

– 1000-V Charged-Device Model (C101)

· Supports Digital Applications: Level

Translation, PCI Interface, USB Interface,

Memory Interleaving, and Bus Isolation

· Ideal for Low-Power Portable Equipment

DESCRIPTION/ORDERING INFORMATION

The SN74CB3T16212 is a high-speed TTL-compatible FET bus-exchange 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 SN74CB3T16212 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 SN74CB3T16212 operates as a 24-bit bus switch or as a 12-bit bus exchange that provides data

exchanging between four signal ports. The select (S0, S1, S2) inputs control the data path of the bus-exchange

switch. When the bus-exchange switch is ON, the A port is connected to the B port, allowing bidirectional data

flow between ports. When the bus-exchange switch is OFF, 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, each select input should be tied to GND

through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability of

the driver.