8-BIT FET BUF SWITCH 2.5V-/3.3V LOW-VOLTAGE HIGH BANDWIDTH BUS SWITCH

DESCRIPTION

The U74CB3Q3245 is a high-bandwidth FET bus switch utilizing

a charge pump to elevate the gate voltage of the pass transistor,

providing a low and flat ON-state resistance (RON). The low and flat

ON-state resistance allows for minimal propagation delay and

supports rail-to-rail switching on the data input/output (I/O) ports.

The device also features low data I/O capacitance to minimize

capacitive loading and signal distortion on the data bus. Specifically

designed to support high-bandwidth applications, The UTC

U74CB3Q3245 provides an optimized interface solution ideally

suited for broadband communications, networking, and

data-intensive computing systems.

The UTC U74CB3Q3245 is organized as an 8-bit bus switch with

a single output-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 circuitry prevents damaging current 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 pull up resistor; the

minimum value of the resistor is determined by the current-sinking

capability of the driver.

FEATURES

* High-Bandwidth Data Path(up to 500MHz)

* 5V Tolerant I/Os With Device Powered Up or Powered Down

* Low and Flat ON-State Resistance (RON) Characteristics Over Operating Range (RON=4Ω Typ.)

* Rail-to-Rail Switching on Data I/O Ports

–0 to 5V Switching With 3.3V VCC

–0 to 3.3V Switching With 2.5V VCC

* Bidirectional Data Flow With Near-Zero Propagation Delay

* Low Input / Output Capacitance Minimizes Loading and Signal Distortion(Cio(OFF)=3.5pF Typ.)

* Fast Switching Frequency (fOE=20MHz Max.)

* Data and Control Inputs Provide Undershoot Clamp Diodes

* Low Power Consumption (ICC=1mA Typical)

* VCC Operating Range From 2.3V to 3.6V

* Data I/Os Support 0 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

* Supports Both Digital and Analog Applications:

PCI Interface, Differential Signal Interface, Memory

Interleaving, Bus Isolation, Low-Distortion Signal Gating