74LCX646WMX

Overview

The onsemi 74LCX646WMX is a low voltage octal transceiver and register featuring 5V tolerant inputs and outputs. It operates within a supply voltage range of 2.3V to 3.6V, utilizing advanced CMOS technology for high-speed performance with low power dissipation. The device provides multiplexed transmission of data directly from the input bus or internal storage registers. Key electrical specifications include a maximum propagation delay of 7.0 ns at VCC = 3.3V, a maximum quiescent supply current of 10 µA, and an output drive capability of ±24 mA at VCC = 3.0V.

Feature Summary

• Supports live insertion and withdrawal capabilities
• Implements patented noise and EMI reduction circuitry
• Provides power-down high impedance state for inputs and outputs
• Features latch-up performance exceeding 500 mA

Applications

• Bus management systems requiring multiplexed data transmission
• Interfacing low voltage logic circuits with 5V signal environments
• Registered bus transceiver applications in portable electronics
• High-speed data transfer between microprocessors and memory modules

Procurement Notes

Verify that the ordering code includes the 'X' suffix to confirm availability in tape and reel packaging. Ensure compatibility with the specified 24-lead SOIC package (M24B) for your design requirements. Confirm that the manufacturer designation aligns with onsemi or Fairchild Semiconductor standards. Check for any specific environmental compliance certifications required by your project specifications before finalizing procurement orders.

Selection Notes

Select this component when designing systems requiring octal bidirectional data transfer with registered storage capabilities. It is suitable for applications needing interface between 2.5V/3.3V logic and 5V tolerant buses. Consider the 7.0 ns propagation delay and ±24 mA drive strength for timing and load requirements. Ensure adequate decoupling and proper handling of unused inputs to maintain stable operation within the -40°C to +85°C temperature range.

Part Context

This part belongs to the LCX family of low-voltage CMOS logic devices, designed for high-speed operation with reduced power consumption. The 74LCX646 specifically functions as an octal transceiver/register, combining bus driving and data storage in a single package. It is manufactured using advanced CMOS technology to achieve performance levels comparable to faster logic families while maintaining lower power dissipation characteristics typical of CMOS devices.

Replacement Considerations

Check datasheets for equivalent parts from other manufacturers offering similar octal transceiver functionality with 5V tolerance. Verify pinout compatibility and electrical parameters such as propagation delay and output drive current. Ensure that any substitute device supports the same operating voltage range and package type if physical replacement is required without PCB redesign.

FAQ

How does the device handle data during power-down?

During power-down, the inputs and outputs enter a high-impedance state. To ensure this state is maintained, the OE pin should be tied to VCC through a pull-up resistor.

What is the maximum clock frequency supported?

The maximum clock frequency is 150 MHz under recommended operating conditions.

Can this device interface directly with 5V signals?

Yes, the 74LCX646WMX features 5V tolerant inputs and outputs, allowing it to interface directly with 5V signal environments while operating at lower supply voltages.