Overview
The SN74LS245DBRG4 is an octal bus transceiver produced by Texas Instruments, designed for asynchronous two-way communication between data buses. This device is part of the SNx4LS245 family and is particularly useful in applications requiring data transmission between two buses with minimal external timing requirements. The control-function implementation allows data to be transmitted from the A bus to the B bus or vice versa, based on the logic level at the direction-control (DIR) input. Additionally, the output-enable (OE) input can isolate the buses by disabling the device.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package Type | SSOP (DB) | - |
| Pins | 20 | - |
| Operating Temperature Range | 0 to 70 | °C |
| Supply Voltage | 4.5 to 5.5 | V |
| High-Level Input Voltage (VIH) | 2 | V |
| Low-Level Input Voltage (VIL) | 0.7 to 0.8 | V |
| High-Level Output Voltage (VOH) | 2.4 to 3.4 | V |
| Propagation Delay Time (tPLH, tPHL) | 8 to 12 | ns |
| Output Enable Time to Low Level (tPZL) | 27 to 40 | ns |
| Output Enable Time to High Level (tPZH) | 25 to 40 | ns |
Key Features
- 3-State Outputs: The outputs can drive bus lines directly and can be put into high impedance mode through the OE pin.
- PNP Inputs: These inputs reduce DC loading on bus lines, enhancing overall efficiency.
- Hysteresis on Bus Inputs: Built-in hysteresis improves noise margins, ensuring reliable data transmission.
- Typical Propagation Delay Times: Port to port propagation delay times are typically around 8 ns, making it suitable for high-speed applications.
Applications
- Electronic Point of Sale: Suitable for POS systems requiring reliable and fast data communication.
- Factory Automation and Control: Used in industrial automation for efficient data exchange between different parts of the system.
- Test and Measurement: Ideal for test and measurement equipment that require precise and reliable data transmission.
Q & A
- What is the primary function of the SN74LS245DBRG4? The primary function is to facilitate asynchronous two-way communication between data buses.
- How does the direction-control (DIR) input work? The DIR input determines the direction of data transmission between the A and B buses.
- What is the purpose of the output-enable (OE) input? The OE input can disable the device, effectively isolating the buses.
- What are the typical propagation delay times for this device? The typical propagation delay times are around 8 ns.
- What is the operating temperature range for the SN74LS245DBRG4? The operating temperature range is from 0 to 70°C.
- What types of inputs does the SN74LS245DBRG4 have? The device has PNP inputs which reduce DC loading on bus lines.
- Does the SN74LS245DBRG4 have built-in hysteresis? Yes, it has built-in hysteresis on bus inputs to improve noise margins.
- What is the supply voltage range for this device? The supply voltage range is between 4.5 V and 5.5 V.
- What are some common applications of the SN74LS245DBRG4? It is commonly used in electronic point of sale, factory automation, and test and measurement equipment.
- What package type is the SN74LS245DBRG4 available in? It is available in the SSOP (DB) package type.
