SN74CBTD3305CPWRE4

Overview

The SN74CBTD3305CPWRE4 is a dual FET bus switch with level shifting and –2-V undershoot protection. It operates within a VCC range of 4.5 V to 5.5 V, supporting data I/O levels from 0 V to 5 V. The device features low ON-state resistance (ron) of 3 Ω typical and propagation delay (tpd) of 0.15 ns. It includes integrated diodes for level shifting and active undershoot protection up to -2 V on A and B ports.

Feature Summary

• Integrated diode in series with VCC provides level shifting for 5-V input down to 3.3-V output levels
• Active undershoot-protection circuitry ensures proper OFF state during undershoot events up to -2 V
• Bidirectional data flow with near-zero propagation delay and low ON-state resistance
• Supports partial-power-down mode operation using Ioff feature to prevent backflow current

Applications

• USB interface
• Memory interleaving
• Bus isolation
• Low-distortion signal gating

Procurement Notes

Verify the ordering suffix 'E4' indicates lead-free status and RoHS compliance per Texas Instruments standards. Confirm the package type matches the required PCB layout, as this specific part number corresponds to the TSSOP-8 (PW) package. Ensure control inputs are tied to VCC or GND to maintain proper device operation and avoid floating states.

Selection Notes

Select this component when bidirectional switching between 5-V and 3.3-V domains is required. The integrated level-shifting diode simplifies design by eliminating external components for voltage translation. Active undershoot protection makes it suitable for noisy environments where signal integrity is critical. Verify that the operating temperature range of -40°C to 85°C meets application requirements.

Part Context

This device belongs to the SN74CBT family of high-speed TTL-compatible FET bus switches. It is designed for applications requiring minimal propagation delay and low loading. The dual configuration allows independent control of two 1-bit switches or combined operation as a single 2-bit switch via separate OE inputs.

Replacement Considerations

SN74CBTD3305CDR is a SOIC-8 alternative with identical electrical characteristics but different packaging. SN74CBTD3305CD offers tube packaging instead of tape and reel. Both maintain the same functional specifications including level shifting and undershoot protection capabilities.

FAQ

How does the device handle undershoot events?

The SN74CBTD3305C features active undershoot-protection circuitry on the A and B ports that senses undershoot events and ensures the switch remains in the proper OFF state, providing protection up to -2 V.

What is the purpose of the integrated diode?

The integrated diode in series with VCC provides level shifting capability, allowing 5-V input signals to be shifted down to 3.3-V output levels without additional external components.