Overview
The SN74LVC8T245DWR is an 8-bit non-inverting bus transceiver produced by Texas Instruments. This device is designed with configurable dual power supply rails, enabling bidirectional voltage level translation between different voltage nodes. It operates with VCCA and VCCB set at any voltage from 1.65 V to 5.5 V, making it suitable for translating between 1.8-V, 2.5-V, 3.3-V, and 5.5-V voltage levels. The device is optimized for asynchronous communication between two data buses and features control inputs (DIR and OE) that determine the direction of data transmission and the output state.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Package | SOIC (DW) | 24 pins |
| Operating Temperature Range | °C | -40 to 85 |
| Power Supply Range | VCCA and VCCB | 1.65 V to 5.5 V |
| Low-Level Output Current | mA | 4 (1.65 V to 1.95 V), 8 (2.3 V to 2.7 V), 24 (3 V to 3.6 V), 32 (4.5 V to 5.5 V) |
| Input Transition Rise or Fall Rate | ns/V | 20 (1.65 V to 1.95 V), 20 (2.3 V to 2.7 V), 10 (3 V to 3.6 V), 5 (4.5 V to 5.5 V) |
| ESD Protection | V | 4000-V Human-Body Model, 100-V Machine Model, 1000-V Charged-Device Model |
| Latch-Up Performance | mA | Exceeds 100 mA per JESD 78, class II |
Key Features
- Control Inputs VIH/VIL Levels: Referenced to VCCA voltage.
- VCC Isolation Feature: If either VCC input is at GND, all outputs are in the high-impedance state.
- Fully Configurable Dual-Rail Design: Each port can operate over the full 1.65-V to 5.5-V power-supply range.
- ESD Protection: Exceeds JESD 22 standards with 4000-V Human-Body Model, 100-V Machine Model, and 1000-V Charged-Device Model.
- Latch-Up Performance: Exceeds 100 mA per JESD 78, class II.
- Partial-Power-Down Mode: Ioff circuitry disables the outputs, preventing damaging current backflow when the device is powered down.
- Balanced High-Drive CMOS Push-Pull Outputs: Capable of sinking and sourcing similar currents, creating fast edges into light loads.
Applications
- Personal Electronics: Suitable for various consumer electronic devices.
- Industrial: Used in industrial automation and control systems.
- Enterprise: Applied in enterprise-level computing and networking equipment.
- Telecom: Utilized in telecommunications infrastructure.
Q & A
- What is the primary function of the SN74LVC8T245DWR?
The SN74LVC8T245DWR is an 8-bit non-inverting bus transceiver that enables bidirectional voltage level translation between different voltage nodes.
- What is the power supply range for the SN74LVC8T245DWR?
The device operates with VCCA and VCCB set at any voltage from 1.65 V to 5.5 V.
- How does the direction-control (DIR) input work?
The DIR input determines the direction of data transmission; a high on DIR allows data transmission from A to B, and a low on DIR allows data transmission from B to A.
- What is the purpose of the output-enable (OE) input?
The OE input activates or deactivates the output ports; when OE is low, the outputs are enabled, and when OE is high, the outputs are in the high-impedance state.
- What is the significance of the VCC isolation feature?
If either VCC input is at GND, all outputs are in the high-impedance state, preventing any potential damage.
- How does the Ioff circuitry work?
The Ioff circuitry disables the outputs when the device is in partial-power-down mode, preventing damaging current backflow.
- What kind of ESD protection does the SN74LVC8T245DWR have?
The device exceeds JESD 22 standards with 4000-V Human-Body Model, 100-V Machine Model, and 1000-V Charged-Device Model ESD protection.
- What is the latch-up performance of the SN74LVC8T245DWR?
The device exceeds 100 mA per JESD 78, class II, for latch-up performance.
- What are the typical applications of the SN74LVC8T245DWR?
The device is used in personal electronics, industrial automation, enterprise computing, and telecommunications infrastructure.
- How should unused control inputs be handled?
Unused control inputs must be held at VCCA or GND to ensure proper device operation and minimize power consumption.
