描述 Description

The SN74CB3Q32245 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 SN74CB3Q32245 provides an optimized interface solution ideally suited for broadband communications, networking, and data-intensive computing systems.
The SN74CB3Q32245 is organized as four 8-bit bus switches with separate output-enable (1OE\\, 2OE\\, 3OE\\, 4OE\\) inputs. It can be used as four 8-bit bus switches, two 16-bit bus switches, or as one 32-bit bus switch. When OE\\ is low, the associated 8-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 8-bit 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 pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

特性 Features

·Member of the Texas Instruments Widebus+? Family ·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 (ron) Characteristics Over Operating Range (ron = 5 Typical) ·Rail-to-Rail Switching 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/Output Capacitance Minimizes Loading and Signal Distortion (Cio(OFF) = 4 pF Typical) ·Fast Switching Frequency (fOE\\ = 20 MHz Max) ·Data and Control Inputs Provide Undershoot Clamp Diodes ·Low Power Consumption (ICC = 2 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, 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 ·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: PCI Interface, Differential Signal Interface, Memory Interleaving, Bus Isolation, Low-Distortion Signal Gating
For additional information regarding the performance characteristics of the CB3Q family, refer to the TI application report, CBT-C, CB3T, and CB3Q Signal-Switch Families, literature number SCDA008. Widebus+ is a trademark of Texas Instruments.