Overview
The SN74AHCT245PWR is an octal bus transceiver produced by Texas Instruments, designed for asynchronous two-way communication between data buses. This device operates from 4.5 V to 5.5 V and is optimized for 5 V operation. It features a direction-control (DIR) input that determines the direction of data transmission between the A and B buses, and an output-enable (OE) input that can isolate the buses when set to a high logic level. The SN74AHCT245PWR is part of the AHCT series, which is known for its compatibility with TTL voltage levels and its ability to translate signals from 3.3 V to 5 V.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCC (Supply Voltage) | 4.5 | 5.5 | V | |
| VIH (High-level Input Voltage) | 2 | 2 | V | |
| VIL (Low-level Input Voltage) | 0.8 | 0.8 | V | |
| IOH (High-level Output Current) | -8 | -8 | mA | |
| IOL (Low-level Output Current) | 8 | 8 | mA | |
| TA (Operating Free-Air Temperature) | -40 | 85 | °C | |
| tPLH (Propagation Delay Time, A or B to B or A) | 4.5 | 7.7 | 10 | ns |
| tPHL (Propagation Delay Time, A or B to B or A) | 4.5 | 7.7 | 10 | ns |
Key Features
- Inputs are TTL-voltage compatible.
- Latch-up performance exceeds 250 mA per JESD 17.
- Allows up voltage translation from 3.3 V to 5 V.
- Slow edge rates minimize output ringing.
- Output-enable (OE) input for bus isolation.
- Direction-control (DIR) input for bidirectional data transmission.
- Operates from 4.5 V to 5.5 V.
- High-impedance state during power up or power down when OE is tied to VCC through a pullup resistor.
Applications
- Enable or disable a digital signal.
- Hold a signal during a controller reset.
- Debounce a switch.
- Bus interface applications where output ringing is a concern.
- Voltage translation from 3.3 V to 5 V.
Q & A
- What is the operating voltage range of the SN74AHCT245PWR?
The operating voltage range is from 4.5 V to 5.5 V. - What is the purpose of the DIR input in the SN74AHCT245PWR?
The DIR input determines the direction of data transmission between the A and B buses. - How does the OE input function in the SN74AHCT245PWR?
The OE input can be used to disable the device, effectively isolating the buses. - Is the SN74AHCT245PWR compatible with TTL voltage levels?
Yes, the inputs are TTL-voltage compatible. - What is the maximum high-level output current for the SN74AHCT245PWR?
The maximum high-level output current is -8 mA. - What is the recommended operating temperature range for the SN74AHCT245PWR?
The recommended operating temperature range is from -40°C to 85°C. - How does the SN74AHCT245PWR minimize output ringing?
The device features slow edge rates to minimize output ringing. - Can the SN74AHCT245PWR translate signals from 3.3 V to 5 V?
Yes, it can translate signals from 3.3 V to 5 V. - What is the typical propagation delay time for the SN74AHCT245PWR?
The typical propagation delay time is around 7.7 ns. - How should the OE input be configured during power up or power down to ensure a high-impedance state?
The OE input should be tied to VCC through a pullup resistor.
