Overview
The SN74AVC8T245PWRE4, produced by Texas Instruments, is an 8-bit dual-supply noninverting bidirectional bus transceiver. This device is designed to facilitate voltage level translation between different voltage nodes, making it versatile for use in various low-voltage applications. It operates with two separate configurable power-supply rails, allowing each port to function over a wide range of voltages from 1.2 V to 3.6 V. The device is optimized for asynchronous communication between data buses and features control inputs and outputs that can be isolated using the output-enable (OE) input.
Key Specifications
| Parameter | Value |
|---|---|
| Package | TSSOP (24 pins) |
| Operating Temperature Range | -40°C to 125°C |
| Power Supply Range (VCCA/VCCB) | 1.2 V to 3.6 V |
| Maximum Data Rates | 170 Mbps (VCCA < 1.8 V or VCCB < 1.8 V), 320 Mbps (VCCA ≥ 1.8 V and VCCB ≥ 1.8 V) |
| I/O Voltage Tolerance | 4.6 V |
| ESD Protection | 8000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model |
| Latch-up Performance | Exceeds 100 mA per JESD 78, Class II |
Key Features
- Fully configurable dual-rail design allowing each port to operate over the full 1.2-V to 3.6-V power-supply range.
- Supports partial power-down mode operation with Ioff circuitry.
- VCC isolation feature – if either VCC input is at GND, all I/O ports are in the high-impedance state.
- Control inputs VIH/VIL levels are referenced to VCCA voltage.
- ESD protection exceeds JESD 22 standards.
- Latch-up performance exceeds 100 mA per JESD 78, Class II.
- I/Os are 4.6-V tolerant.
Applications
The SN74AVC8T245PWRE4 is suitable for a variety of applications requiring voltage level translation, such as:
- Asynchronous communication between data buses in mixed-voltage systems.
- Universal low-voltage bidirectional translation between different voltage nodes (e.g., 1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V).
- Partial power-down applications where Ioff circuitry is necessary to prevent current backflow.
- Single-supply systems that may need to be upgraded to dual-supply systems with minimal PCB redesign.
Q & A
- What is the primary function of the SN74AVC8T245PWRE4?
The primary function is to act as an 8-bit dual-supply noninverting bidirectional bus transceiver, facilitating voltage level translation between different voltage nodes.
- What is the operating temperature range of the SN74AVC8T245PWRE4?
The operating temperature range is -40°C to 125°C.
- What are the power supply ranges for VCCA and VCCB?
Both VCCA and VCCB can operate from 1.2 V to 3.6 V.
- What are the maximum data rates supported by the device?
The device supports up to 170 Mbps when either VCCA or VCCB is below 1.8 V, and up to 320 Mbps when both VCCA and VCCB are 1.8 V or higher.
- How does the VCC isolation feature work?
If either VCC input is at GND, all I/O ports are in the high-impedance state.
- What kind of ESD protection does the device offer?
The device offers ESD protection exceeding JESD 22 standards: 8000-V Human-Body Model, 200-V Machine Model, and 1000-V Charged-Device Model.
- Can the device support partial power-down mode?
Yes, the device supports partial power-down mode operation using Ioff circuitry.
- How do the control inputs (DIR and OE) function?
The control inputs (DIR and OE) are supplied by VCCA. The DIR input determines the direction of data transmission, and the OE input can disable the outputs to isolate the buses.
- Is the device compatible with single-supply systems?
Yes, the device is compatible with single-supply systems and can be replaced later with a 245 function with minimal PCB redesign.
- What is the significance of the I/O voltage tolerance?
The I/Os are 4.6-V tolerant, which means they can handle input voltages up to 4.6 V without damage.
