74CB3Q3305DCURG4屬于集成電路（IC）的信號(hào)開(kāi)關(guān)多路復(fù)用器解碼器。由美國(guó)德州儀器公司制造生產(chǎn)的74CB3Q3305DCURG4信號(hào)開(kāi)關(guān)，多路復(fù)用器，解碼器邏輯型信號(hào)開(kāi)關(guān)、多路復(fù)用器和編碼器 IC 可用于對(duì)以數(shù)字格式表示數(shù)據(jù)的電信號(hào)進(jìn)行路由和選擇。這些器件與設(shè)計(jì)用于模擬信號(hào)的類似產(chǎn)品有所不同，它們保留的信息表示為兩個(gè)電狀態(tài)之一，而不是兩個(gè)外部界限內(nèi)的無(wú)窮變化量。

1 Features

? High-bandwidth data path (up to 500 MHz)1

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

powered down

? Low and flat ON-state resistance (ron)

characteristics over operating range

(ron = 3 Ω typical)

? Supports input voltage beyond supply on data I/O

ports

– 0 to 5 V switching with 3.3 V VCC

– 0 to 3.3 V switching with 2.5 V VCC

? Bidirectional data flow with near-zero propagation

delay

? Low input or output capacitance minimizes loading

and signal distortion

(Cio(OFF) = 3.5 pF typical)

? Fast switching frequency (fOE = 20 MHz maximum)

? Data and control inputs provide undershoot clamp

diodes

? Low power consumption (ICC = 0.25 mA typical)

? 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, and 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 100 mA per JESD

78, Class II

2 Applications

? IP phones: wired and wireless

? Optical modules

? Optical networking: video over fiber and EPON

? Private branch exchange (PBX)

? WiMAX and wireless infrastructure equipment

? USB, differential signal interface

? Bus isolation

3 Description

The SN74CB3Q3305 device is a high-bandwidth FET

bus switch using 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 switching input voltage beyond

the supply 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 highbandwidth

applications, the SN74CB3Q3305 device

provides an optimized interface solution ideally suited

for broadband communications, networking, and dataintensive

computing systems.

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 GND through a

pulldown resistor; the minimum value of the resistor

is determined by the current-sourcing capability of the

driver.