74HC245D

Overview

The Toshiba 74HC245D is a high-speed CMOS octal bus transceiver fabricated with silicon gate C2MOS technology. It provides bidirectional asynchronous communication between data buses with non-inverting outputs. The device operates within a supply voltage range of 2.0 V to 6.0 V and supports an operating temperature range from -40°C to +125°C. Key electrical parameters include a typical propagation delay of 10 ns at 6.0 V, balanced propagation delays (tPLH ≈ tPHL), and a maximum quiescent supply current of 4.0 µA at 25°C. It features three-state outputs controlled by an enable input (G) and direction control via the DIR input.

Feature Summary

• Octal bus transceiver providing two-way asynchronous communication between data busses
• High-speed operation similar to equivalent LSTTL while maintaining low power dissipation
• Three-state outputs allow effective isolation of busses when disabled
• All inputs equipped with protection circuits against static discharge or transient excess voltage

Applications

• Two-way asynchronous communication between data busses
• Bus interface applications requiring direction control
• Systems requiring bus isolation through three-state output control

Procurement Notes

Verify the specific package type SOIC-20 matches the design requirements. Confirm that the operating voltage range of 2.0 V to 6.0 V aligns with the system power supply. Ensure that unused inputs are tied to VCC or GND as specified in the operating ranges. Check for compliance with environmental directives such as RoHS if required by the application standards.

Selection Notes

Select this component for applications requiring high-speed bidirectional data transfer with low power consumption. The wide operating voltage range allows flexibility in system design. Consider the thermal derating of power dissipation above 85°C if operating in high-temperature environments. Ensure that the load capacitance and resistance values remain within the AC characteristics limits for reliable timing performance.

Part Context

The 74HC245D belongs to the 74HC series of high-speed CMOS logic devices. It is functionally compatible with the 74HC640 but provides non-inverting outputs instead of inverting ones. Manufactured using silicon gate C2MOS technology, it offers performance comparable to LSTTL families while retaining the low power advantages of standard CMOS logic families.

Replacement Considerations

The 74HC245D may be replaced by other octal bus transceivers with compatible logic levels and package types. Verify pinout compatibility and electrical specifications such as propagation delay and output drive current before substitution.