Bus Switch 2-Element CMOS 8-IN 20-Pin SSOP T/R

The SN74CB3Q3244 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 SN74CB3Q3244 provides an optimized interface solution ideally suited for broadband communications, networking, and data-intensive computing systems. The SN74CB3Q3244 is organized as two 4-bit bus switches with separate output-enable (1OE, 2OE) inputs. It can be used as two 4-bit bus switches or as one 8-bit bus switch. When OE is low, the associated 4-bit 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 associated 4-bit bus switch is OFF, and the 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 pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

High-Bandwidth Data Path (Up To 500 MHz)

5-V-Tolerant I/Os with Device Powered-Up or Powered-Down

Low and Flat ON-State Resistance (r_on) Characteristics Over Operating Range (r_on = 4 O Typical)

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

• 0- to 5-V Switching With 3.3-V V_CC
• 0- to 3.3-V Switching With 2.5-V V_CC

Bidirectional Data Flow, With Near-Zero Propagation Delay

Low Input/Output Capacitance Minimizes Loading and Signal Distortion (C_io(OFF) = 3.5 pF Typical)

Fast Switching Frequency (f_OE = 20 MHz Max)

Data and Control Inputs Provide Undershoot Clamp Diodes

Low Power Consumption (I_CC = 0.7 mA Typical)

V_CC 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

I_off Supports Partial-Power-Down Mode Operation

Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II

ESD Performance Tested Per JESD 22

• 2000-V Human-Body Model (A114-B, Class II)
• 1000-V Charged-Device Model (C101)

Supports Both Digital and Analog Applications: Differential Signal Interface, Memory Interleaving, Bus Isolation, Low-Distortion Signal Gating