MC74HC245ADTEL

Overview

The MC74HC245ADTEL is an octal bus transceiver manufactured by Motorola, belonging to the HC/UH series. It features true outputs and operates within a supply voltage range of 2 V to 6 V. The device utilizes a 20-pin TSSOP plastic package with a lead pitch of 0.65 mm. Key electrical parameters include a maximum propagation delay of 135 ns at 2 V and 7 ns at 5 V. It supports a load capacitance of 50 pF and functions across a temperature range from -40 °C to +85 °C.

Feature Summary

• Provides asynchronous bidirectional data transmission between two data buses via direction control inputs.
• Features three-state outputs that allow effective isolation of the bus when disabled.
• Offers direct interface compatibility with LSTTL loads without additional pull-up resistors.

Applications

• Asynchronous communication interfaces between microprocessors and memory modules.
• Bidirectional data buffering for system buses in embedded controllers.
• Level shifting applications interfacing CMOS logic with TTL-compatible devices.

Procurement Notes

Verify the specific manufacturer origin, as Motorola's semiconductor assets were acquired by ON Semiconductor. Confirm the exact suffix 'ADTEL' corresponds to the intended tape-and-reel packaging and temperature grade. Ensure the component meets current RoHS compliance standards required for modern assembly processes.

Selection Notes

Select this component for designs requiring wide voltage operation between 2 V and 6 V. It serves as a suitable replacement for legacy LS245 devices where lower power consumption is prioritized over speed. Verify that the 7 ns propagation delay at 5 V meets the timing requirements of the target application bus.

Part Context

This part belongs to the standard 74HC family of high-speed CMOS logic devices. It shares pinout compatibility with older bipolar technologies like 74LS245, facilitating design upgrades. The device integrates eight independent bi-directional channels into a single integrated circuit for compact board layouts.

Replacement Considerations

MC74HC245A (DIP/SOIC variants)

FAQ

What is the function of the DIR input?

The DIR input determines the direction of data flow. A high logic level directs data from port A to port B, while a low logic level directs data from port B to port A.

How does the OE input affect the outputs?

The Output Enable (OE) input controls the state of the outputs. When active low, the transceiver operates normally; when high, the outputs enter a high-impedance state to isolate the bus.