Overview
The MC74HCT245A, produced by onsemi, is a high-performance silicon-gate CMOS device. It is identical in pinout to the LS245 and serves as a 3-state noninverting transceiver for 2-way asynchronous communication between data buses. This device can be used as a level converter to interface TTL or NMOS outputs with high-speed CMOS inputs. The MC74HCT245A features an active-low Output Enable pin to place the I/O ports into high-impedance states, and a Direction control to determine the data flow direction between the two buses.
Key Specifications
| Parameter | Value | Units |
|---|---|---|
| Operating Voltage Range | 4.5 to 5.5 | V |
| Output Drive Capability | 15 | LSTTL Loads |
| Input Current | 1.0 | mA |
| Chip Complexity | 304 FETs or 76 Equivalent Gates | - |
| Propagation Delay | 22 | ns |
| Maximum Output Current | 6 | mA |
| Package Type | TSSOP-20, SOIC-20W | - |
| Temperature Range | -40 to 125 | °C |
Key Features
- TTL/NMOS Compatible Input Levels
- Outputs Directly Interface to CMOS, NMOS, and TTL
- Active-Low Output Enable Pin for High-Impedance States
- Direction Control for Data Flow Direction
- In Compliance with JEDEC Standard No. 7A
- Pb-Free Packages Available
Applications
The MC74HCT245A is suitable for various applications requiring level conversion and asynchronous communication between different logic families. It is particularly useful in systems that need to interface TTL or NMOS outputs with high-speed CMOS inputs. Common applications include data bus communication in microprocessor systems, peripheral devices, and other digital circuits where level conversion and bidirectional data transfer are necessary.
Q & A
- What is the primary function of the MC74HCT245A?
The MC74HCT245A is a 3-state noninverting transceiver used for 2-way asynchronous communication between data buses and can serve as a level converter for interfacing TTL or NMOS outputs to high-speed CMOS inputs.
- What is the operating voltage range of the MC74HCT245A?
The operating voltage range is from 4.5 V to 5.5 V.
- What is the output drive capability of the MC74HCT245A?
The device can drive up to 15 LSTTL loads.
- Is the MC74HCT245A Pb-free and RoHS compliant?
Yes, the MC74HCT245A is available in Pb-free packages and is RoHS compliant.
- What is the propagation delay of the MC74HCT245A?
The propagation delay is up to 22 ns.
- How does the Direction control work on the MC74HCT245A?
The Direction control determines whether data flows from Bus A to Bus B or from Bus B to Bus A.
- What is the purpose of the active-low Output Enable pin?
The active-low Output Enable pin is used to place the I/O ports into high-impedance states.
- Is the MC74HCT245A compatible with different logic families?
Yes, it is compatible with TTL, NMOS, and CMOS logic families.
- What are common applications for the MC74HCT245A?
Common applications include data bus communication in microprocessor systems, peripheral devices, and other digital circuits requiring level conversion and bidirectional data transfer.
- What are the available package types for the MC74HCT245A?
The device is available in TSSOP-20 and SOIC-20W packages.
