Overview
The SN74ABT245BDWR is an octal bus transceiver produced by Texas Instruments. This device is designed for asynchronous communication between data buses, enabling the transmission of data from the A bus to the B bus or vice versa, based on the logic level at the direction-control (DIR) input. The output-enable (OE) input allows the device to be disabled, effectively isolating the buses. This component is particularly useful in applications requiring high-drive outputs and robust ESD protection, making it suitable for a variety of digital systems.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | 20-SOIC (0.295", 7.50mm Width) | |
| Pins | 20 | |
| Operating Temperature Range | -40 to 85 | °C |
| Supply Voltage (VCC) | 4.5 to 5.5 | V |
| High-Level Input Voltage (VIH) | 2 | V |
| Low-Level Input Voltage (VIL) | 0.8 | V |
| High-Level Output Current (IOH) | -32 | mA |
| Low-Level Output Current (IOL) | 64 | mA |
| Input Transition Rise or Fall Rate | 5 | ns/V |
| Power-Up Ramp Rate | 200 | μs/V |
Key Features
- High-Drive Outputs: Capable of sourcing 32 mA and sinking 64 mA, making them suitable for driving long bus lines.
- 3-State Outputs: Outputs can be placed in a high-impedance state, allowing multiple devices to share the same bus.
- Ioff and Power-Up 3-State Support: Ensures outputs are in a high-impedance state during power up and power down, preventing driver conflict and backflow current.
- ESD Protection: Exceeds JESD 22 standards with 2000-V Human-Body Model and 200-V Machine Model protection.
- Latch-Up Performance: Exceeds 500 mA per JEDEC Standard JESD 17.
- Low Output Ground Bounce: Typical VOLP (Output Ground Bounce) is less than 1 V at VCC = 5 V and TA = 25°C.
Applications
The SN74ABT245BDWR is versatile and can be used in various digital systems, including:
- Asynchronous Communication Systems: Ideal for transmitting data between different sections of a digital system.
- Bus Isolation: The 3-state outputs allow for effective isolation of buses, reducing interference and improving system reliability.
- Hot-Insertion Applications: Suitable for systems where devices are inserted or removed while the system is powered on.
- High-Speed Data Transfer: The high-drive outputs and fast transition rates make it suitable for high-speed data transfer applications.
Q & A
- What is the primary function of the SN74ABT245BDWR?
The primary function is to transmit data between two data buses (A and B) in an asynchronous manner, based on the direction-control input.
- What is the package type and pin count of the SN74ABT245BDWR?
The package type is 20-SOIC (0.295", 7.50mm Width) with 20 pins.
- What is the operating temperature range of the SN74ABT245BDWR?
The operating temperature range is -40°C to 85°C.
- What are the supply voltage requirements for the SN74ABT245BDWR?
The supply voltage (VCC) ranges from 4.5 V to 5.5 V.
- What are the high-level and low-level output currents of the SN74ABT245BDWR?
The high-level output current (IOH) is -32 mA, and the low-level output current (IOL) is 64 mA.
- Does the SN74ABT245BDWR support hot-insertion applications?
Yes, it is fully specified for hot-insertion applications using Ioff and power-up 3-state circuitry.
- What kind of ESD protection does the SN74ABT245BDWR offer?
The device exceeds JESD 22 standards with 2000-V Human-Body Model and 200-V Machine Model protection.
- How does the SN74ABT245BDWR handle output ground bounce?
The typical VOLP (Output Ground Bounce) is less than 1 V at VCC = 5 V and TA = 25°C.
- What is the purpose of the output-enable (OE) input?
The output-enable (OE) input can be used to disable the device, placing the outputs in a high-impedance state and effectively isolating the buses.
- How should the OE input be managed during power up or power down?
The OE input should be tied to VCC through a pullup resistor to ensure the high-impedance state during power up or power down.
