Overview
The SN74AC245NSR is an octal bus transceiver produced by Texas Instruments, designed for asynchronous two-way communication between data buses. This device is part of the 74AC series, known for its high-speed CMOS logic. The SN74AC245NSR allows data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (DIR) input. It also features an output-enable (OE) input to isolate the buses when necessary.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 2 | - | 6 | V |
| Input Voltage (VI) | -0.5 | - | VCC + 0.5 | V |
| Output Voltage (VO) | -0.5 | - | VCC + 0.5 | V |
| Operating Free-Air Temperature (TA) | -40 | - | 85 | °C |
| High-Level Output Current (IOH) at VCC = 5.5V | -24 | - | - | mA |
| Low-Level Output Current (IOL) at VCC = 5.5V | 24 | - | - | mA |
| Propagation Delay Time (tPLH) at VCC = 5V | 1.5 | 3.5 | 6.5 | ns |
| Output Enable Time (tPZH) at VCC = 5V | 1.5 | 5 | 8.5 | ns |
| Package Type | - | - | SO (NS) | - |
Key Features
- Wide operating VCC range from 2 V to 6 V
- Inputs accept voltages up to 6 V
- Maximum propagation delay time of 7 ns at VCC = 5 V
- Output enable (OE) input to isolate buses
- Direction-control (DIR) input to control data transmission direction
- Low drive and slow edge rates to minimize output ringing
- CMOS technology with balanced output drive
Applications
- Pro Audio
- Video and Signage
- Appliances
- Factory Automation and Control
- Bus interface applications where output ringing is a concern
Q & A
- What is the primary function of the SN74AC245NSR?
The SN74AC245NSR is designed for asynchronous two-way communication between data buses, allowing data transmission from the A bus to the B bus or from the B bus to the A bus.
- What is the operating voltage range of the SN74AC245NSR?
The device operates within a VCC range of 2 V to 6 V.
- How does the output-enable (OE) input function?
The OE input can be used to disable the device, effectively isolating the buses.
- What is the maximum propagation delay time at VCC = 5 V?
The maximum propagation delay time (tPLH) at VCC = 5 V is 6.5 ns.
- What are the typical applications of the SN74AC245NSR?
It is used in Pro Audio, Video and Signage, Appliances, Factory Automation and Control, and other bus interface applications where output ringing is a concern.
- How does the device minimize output ringing?
The device uses low drive and slow edge rates to minimize output ringing.
- What is the package type of the SN74AC245NSR?
The package type is SO (NS).
- What are the recommended operating conditions for the input voltage?
The input voltage should be between -0.5 V and VCC + 0.5 V.
- What is the maximum continuous output current per output?
The maximum continuous output current per output is 50 mA.
- How should unused inputs be handled to ensure proper device operation?
Unused inputs must be held at VCC or GND to ensure proper device operation.
