Overview
The SN74LVC8T245PW is an 8-bit non-inverting bus transceiver produced by Texas Instruments. This device is designed for bidirectional voltage level translation and is optimized to operate with two separate configurable power-supply rails, VCCA and VCCB, which can be set at any voltage between 1.65 V and 5.5 V. This allows for universal low-voltage bidirectional translation between various voltage nodes such as 1.8 V, 2.5 V, 3.3 V, and 5.5 V. The device is suitable for asynchronous communication between two data buses and features control inputs for direction and output enable, allowing data transmission in either direction or placing both output ports in a high-impedance state.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package Type | TSSOP (PW) | - |
| Pins | 24 | - |
| Operating Temperature Range | -40 to 85 | °C |
| Supply Voltage Range (VCCA, VCCB) | 1.65 to 5.5 | V |
| Input Voltage Range (A and B ports) | -0.5 to 6.5 | V |
| ESD Protection | 4000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model | - |
| Latch-Up Performance | Exceeds 100 mA per JESD 78, Class II | - |
| Junction-to-Ambient Thermal Resistance (RθJA) | 90.6 | °C/W |
Key Features
- Fully configurable dual-rail design allowing each port to operate over the full 1.65-V to 5.5-V power-supply range.
- VCC isolation feature – if either VCC input is at GND, all outputs are in the high-impedance state.
- Control inputs VIH/VIL levels are referenced to VCCA voltage.
- ESD protection exceeds JESD 22 standards – 4000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model.
- Latch-up performance exceeds 100 mA per JESD 78, Class II.
- Designed for asynchronous communication between two data buses with direction-control (DIR) and output-enable (OE) inputs.
- Input circuitry on both A and B ports is always active and must have a logic HIGH or LOW level applied to prevent excess ICC and ICCZ.
Applications
The SN74LVC8T245PW is suitable for a variety of applications requiring bidirectional voltage level translation, including:
- Asynchronous communication between two data buses operating at different voltage levels.
- Universal low-voltage bidirectional translation between 1.8 V, 2.5 V, 3.3 V, and 5.5 V voltage nodes.
- Systems requiring ESD protection and latch-up performance.
- Partial-power-down applications using Ioff circuitry to prevent damaging current backflow.
Q & A
- What is the primary function of the SN74LVC8T245PW?
The primary function is to perform bidirectional voltage level translation between two data buses operating at different voltage levels.
- What is the operating temperature range of the SN74LVC8T245PW?
The operating temperature range is -40°C to 85°C.
- What are the possible supply voltage ranges for VCCA and VCCB?
Both VCCA and VCCB can be set at any voltage between 1.65 V and 5.5 V.
- How does the VCC isolation feature work?
If either VCC input is at GND, all outputs are in the high-impedance state.
- What kind of ESD protection does the SN74LVC8T245PW offer?
The device offers ESD protection exceeding JESD 22 standards – 4000-V Human-Body Model, 200-V Machine Model, 1000-V Charged-Device Model.
- How does the latch-up performance of the SN74LVC8T245PW compare to industry standards?
The latch-up performance exceeds 100 mA per JESD 78, Class II.
- What are the control inputs for the SN74LVC8T245PW and how do they function?
The control inputs are the direction-control (DIR) and output-enable (OE) inputs. These inputs activate either the B-port outputs or the A-port outputs or place both output ports into the high-impedance mode.
- Why is it important to have logic HIGH or LOW levels applied to the input circuitry on both A and B ports?
This is necessary to prevent excess ICC and ICCZ.
- Can the SN74LVC8T245PW be used in partial-power-down applications?
- What types of packages are available for the SN74LVC8T245?
The device is available in TSSOP (PW), SOIC, and VQFN packages.
