描述 Description

The SN74CBT16245C is a high-speed TTL-compatible FET bus switch with low ON-state resistance (ron), allowing for minimal propagation delay. Active Undershoot-Protection Circuitry on the A and B ports of the SN74CBT16245C provides protection for undershoot up to ?2 V by sensing an undershoot event and ensuring that the switch remains in the proper OFF state.

The SN74CBT16245C is organized as two 8-bit bus switches with separate output-enable (1OE\\, 2OE\\) inputs. It can be used as two 8-bit bus switches or as one 16-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 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 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, 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
? Undershoot Protection for Off-Isolation on A and B Ports Up to –2 V
? Bidirectional Data Flow, With Near-Zero Propagation Delay
? Low ON-State Resistance (ron) Characteristics (ron = 3 Typical)
? Low Input/Output Capacitance Minimizes Loading and Signal Distortion (Cio(OFF) = 5.5 pF Typical)
? Data and Control Inputs Provide Undershoot Clamp Diodes
? Low Power Consumption (ICC = 3 μA Max)
? VCC Operating Range From 4 V to 5.5 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, Memory Interleaving, Bus Isolation, Low-Distortion Signal Gating
Widebus is a trademark of Texas Instruments.