Overview
The SN74HC245AN is an octal bus transceiver with 3-state outputs, manufactured by Texas Instruments. This device is designed for asynchronous two-way communication between data buses, making it a versatile component in digital systems. The SN74HC245AN 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. Additionally, the output-enable (OE) input can be used to disable the device, effectively isolating the buses during power-up or power-down to ensure a high-impedance state.
Key Specifications
| Parameter | Min | Nom | Max | Unit |
|---|---|---|---|---|
| VCC Supply Voltage | 2 | 5 | 6 | V |
| VIH High-Level Input Voltage | 1.5 (VCC=2V) | 3.15 (VCC=4.5V) | 4.2 (VCC=6V) | V |
| VIL Low-Level Input Voltage | 0.5 (VCC=2V) | 1.35 (VCC=4.5V) | 1.8 (VCC=6V) | V |
| IO Continuous Output Current | -35 | 35 | mA | |
| Tstg Storage Temperature | -65 | 150 | °C | |
| TA Operating Free-Air Temperature | -40 | 85 | °C | |
| t pd Propagation Delay (A or B to B or A) | 12 (VCC=6V) | 18 (VCC=6V) | 27 (VCC=6V) | ns |
Key Features
- Wide operating voltage range of 2 V to 6 V.
- High-current 3-state outputs capable of driving bus lines directly or up to 15 LSTTL loads.
- Direction-control (DIR) input to select the direction of data transmission between the A and B buses.
- Output-enable (OE) input to disable the device and isolate the buses.
- Minimized external timing requirements due to control-function implementation.
- Available in various packages including DB (SSOP), DW (SOIC), N (PDIP), NS (SO), and PW (TSSOP).
Applications
- Data transmission and bus isolation in digital systems.
- Asynchronous two-way communication between data buses.
- Use in microprocessor and microcontroller systems for bus management.
- Applications requiring high-impedance state during power-up or power-down.
- General-purpose digital logic circuits where bus transceivers are necessary.
Q & A
- What is the operating voltage range of the SN74HC245AN?
The operating voltage range is from 2 V to 6 V.
- How does the direction-control (DIR) input function?
The DIR input selects 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 be used to disable the device, effectively isolating the buses.
- What are the available packages for the SN74HC245AN?
The device is available in DB (SSOP), DW (SOIC), N (PDIP), NS (SO), and PW (TSSOP) packages.
- What is the maximum continuous output current for the SN74HC245AN?
The maximum continuous output current is ±35 mA.
- What is the storage temperature range for the SN74HC245AN?
The storage temperature range is from -65°C to 150°C.
- What is the typical propagation delay for the SN74HC245AN at VCC = 6 V?
The typical propagation delay is 18 ns.
- Can the SN74HC245AN drive LSTTL loads?
- How does the SN74HC245AN ensure a high-impedance state during power-up or power-down?
The OE input should be used to ensure the high-impedance state during power-up or power-down.
- What are common applications for the SN74HC245AN?
