The M54HC7245 / 7640 / 7643 / 7645 M74HC7245 / 7640 / 7643 / 7645 is an eight-way bus transceiver with high speed, low power consumption and high noise immunity, capable of driving 15 LSTTL loads. These ICs are intended for two-way asynchronous communication between data buses, and the direction of data transmission is determined by DIR input. The enable input (G) can be used to disable the device so that the buses are effectively isolated.
The M54HC7245/7640/7643/7645 and M74HC7245/7640/7643/7645 are octal bus transceiver ICs with three‑state outputs. They use high‑speed CMOS technology to achieve LSTTL‑compatible speeds and feature low power dissipation, high noise immunity, and the ability to drive up to 15 LSTTL loads. Direction control (DIR) and enable (G) inputs allow bidirectional data communication and bus isolation.
The datasheet lists absolute maximum ratings, recommended operating conditions, DC and AC electrical characteristics, and mechanical dimensions for plastic DIP20, ceramic DIP20, S020, and PLCC20 packages. Key parameters include a typical propagation delay of 12 ns at 5 V, a supply voltage range of 2 V to 6 V, and a power dissipation limit of 500 mW.
| Typical propagation delay (tpp) | 12 ns at Vcc=5 V |
|---|---|
| Maximum low‑power dissipation (loc) | 4 A at Ta=25 °C |
| High noise immunity (Vi) | 1.1 V typ. at Voc=5 V |
| Output drive capability | 15 LSTTL loads |
| Supply voltage range | 2 V to 6 V |
| Power dissipation (Pp) | 500 mW |
The typical propagation delay is 12 ns when powered at 5 V.
It can drive up to 15 LSTTL loads.
The device operates from 2 V up to 6 V.
The maximum power dissipation is 500 mW.