SNJ54BCT540J

Overview

The SNJ54BCT540J is an octal buffer and line driver featuring three-state outputs, manufactured by Texas Instruments. It utilizes a state-of-the-art BiCMOS design to significantly reduce quiescent current. The device operates within a supply voltage range of 4.5 V to 5.5 V and supports an operating free-air temperature range from -55°C to 125°C. It contains eight input lines and eight output lines with inverted polarity. The package is a 20-pin Ceramic Dual In-Line Package (CDIP). High-level output current is specified at -15 mA, while low-level output current reaches 64 mA. Propagation delay is typically 5.8 ns at 5 V.

Feature Summary

• Features inputs and outputs on opposite sides of the package to facilitate printed circuit board layout.
• Includes dual active-low output-enable inputs that drive all corresponding outputs to a high-impedance state when asserted.
• Provides ESD protection exceeding 2000-V human-body model, 200-V machine model, and 1000-V charged-device model standards.

Applications

• Driving bus lines
• Buffering memory address registers

Procurement Notes

Verify the specific ordering suffix 'J' corresponds to the CDIP package and military-grade temperature rating (-55°C to 125°C) required for your application. Confirm RoHS status, as indicated in documentation, parts with this suffix may not be compliant. Ensure compatibility with MIL-PRF-38535 specifications if critical parameter testing is mandated for your system requirements.

Selection Notes

Select this component when bidirectional data transfer is unnecessary, as it functions strictly as a unidirectional buffer. Consider alternative BCT series devices if lower propagation delays or different pinout configurations are required. Verify that the 3-state control logic aligns with the system's bus arbitration scheme, specifically regarding the active-low enable inputs.

Part Context

This part belongs to the SN54BCT540 family of octal buffers and line drivers. The 'SNJ' prefix denotes a military-grade device produced under quality assurance standards, distinct from commercial 'SN74' variants. It shares functional similarities with other BCT series components but offers extended temperature ranges suitable for harsh environments.

Replacement Considerations

SNJ54BCT540W

FAQ

How does the device handle power-up or power-down states?

To ensure the high-impedance state during power transitions, the OE inputs should be tied to VCC through a pullup resistor, with the minimum value determined by the driver's current-sinking capability.

What is the function of the two output-enable inputs?

The 3-state control gate consists of two active-low inputs (OE1 and OE2). If either input is high, all corresponding outputs enter a high-impedance state.