MC74HC540AFG

Overview

The MC74HC540AFG is an octal inverting buffer and line driver manufactured by onsemi. It utilizes high-performance silicon-gate CMOS technology to provide robust signal buffering for bus-oriented systems, memory address drivers, and clock drivers. The device features inputs and outputs located on opposite sides of the package to facilitate printed circuit board layout. It operates within a supply voltage range of 2.0 V to 6.0 V and includes two active-low output enables that function via ANDed logic. When either enable pin is high, all eight outputs enter a high-impedance state.

Feature Summary

• Octal inverting buffer design with inputs and outputs positioned on opposite package sides
• Dual active-low output enables utilizing ANDed logic for three-state control
• High noise immunity characteristic of CMOS devices
• Outputs directly interface to CMOS, NMOS, and TTL loads

Applications

• Three-state memory address drivers
• Clock drivers
• Bus-oriented systems

Procurement Notes

Verify the specific suffix 'FG' against official ordering information, as standard datasheets list 'DWG' (SOIC-20 Wide) and 'DTG' (TSSOP-20). Confirm package type and lead-free status ('G') match project requirements. Ensure automotive qualification ('-Q' suffix) is not required unless explicitly specified, as standard parts lack AEC-Q100 certification.

Selection Notes

Select this component when an octal inverting buffer with three-state capability is required for system buses. It serves as a functional equivalent to LS540 pinouts while offering CMOS compatibility. Consider the operating temperature range of -55°C to +125°C for industrial environments. Verify input compatibility with Standard CMOS or LSTTL outputs using external pull-up resistors if necessary.

Part Context

This device belongs to the HC540A family of octal buffers. It is functionally similar to the non-inverting HC541A but provides inverted outputs. The part is designed for high-speed operation with propagation delays ranging from 15 ns to 80 ns depending on supply voltage. It contains 124 FETs or 31 equivalent gates and supports up to 15 LSTTL loads per output.

Replacement Considerations

The MC74HC540A/D is identical in pinout to the LS540. For non-inverting applications, the HC541A is the functional counterpart. Automotive-grade versions are available with the '-Q' suffix, such as MC74HC540ADTR2G-Q.