SN74CB3T3383DW

Overview

The SN74CB3T3383DW is a high-speed TTL-compatible FET bus-exchange switch in a 24-pin SOIC package. It operates with a supply voltage (VCC) ranging from 2.3 V to 3.6 V and supports data I/O voltages from 0 V to 5.5 V. The device features low ON-state resistance (ron), typically 5 Ω at VCC = 2.5 V, and bidirectional data flow with near-zero propagation delay (tpd) of 150 ps to 250 ns depending on VCC. It includes an enable (BE) input for bus exchange functionality and provides partial-power-down protection via the Ioff feature.

Feature Summary

• Supports mixed-mode signal operation by providing voltage translation that tracks VCC, enabling level shifting between 5-V, 3.3-V, and 2.5-V standards.
• Configurable as a 10-bit bus switch or a 5-bit bus-exchange switch using the BE and BX control inputs to route data between ports.
• Ensures isolation during power-off states through the Ioff feature, preventing damaging backflow current when the device is unpowered.
• Features 5-V-tolerant I/Os that remain safe even when the device is powered down, supporting various signaling levels including 0.8 V, 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V, and 5 V.

Applications

• Level translation between different logic families
• Memory interleaving systems
• Bus isolation in mixed-voltage environments

Procurement Notes

Verify the specific ordering suffix 'DW' corresponds to the SOIC-24 tube packaging configuration. Confirm the operating temperature range matches the application requirements of -40°C to +85°C. Ensure control inputs are properly biased to VCC or GND to maintain stable operation. Check for RoHS compliance status if environmental regulations apply to the final assembly.

Selection Notes

Select this component when bidirectional switching with voltage translation is required in low-voltage portable equipment. The device is suitable for applications needing minimal loading due to low input/output capacitance. Consider the SOIC-24 package dimensions for PCB layout constraints. Verify that the control circuitry can drive the required VIH and VIL levels across the full operating voltage range.

Part Context

This part belongs to the SN74CB3T3383 family of high-speed FET bus switches. It is functionally equivalent to other variants in the series such as SN74CB3T3383DWR (tape and reel), SN74CB3T3383PW (TSSOP), and SN74CB3T3383DGVR (TVSOP). The primary distinction lies in the physical package type and shipping quantity, while the electrical characteristics and pinout remain consistent across these options.

Replacement Considerations

Direct substitutes include SN74CB3T3383DWR, SN74CB3T3383PW, and SN74CB3T3383DGVR. These parts share identical electrical specifications and pin configurations but differ in package style (SOIC, TSSOP, TVSOP) and packaging format (tube vs. tape and reel). Ensure the replacement package fits the existing footprint or allows for re-layout.

FAQ

How does the device handle partial-power-down scenarios?

The SN74CB3T3383DW supports partial-power-down mode via the Ioff feature. This ensures that no damaging current flows back through the device when it is powered down, maintaining isolation between the powered and unpowered sections of the system.

What is the function of the BE and BX inputs?

When used as a 5-bit bus-exchange switch, the BE (Enable) and BX (Select) inputs control the data path. If BE is low, the switch is ON, and BX determines whether A ports connect to B1 or B2 ports. If BE is high, the switch is OFF, creating a high-impedance state between the A and B ports.