Overview
The SN74AVCH2T45, produced by Texas Instruments, is a 2-bit, 2-supply, bus transceiver designed for universal low-voltage bidirectional translation and level-shifting between different voltage nodes. This device is capable of operating with supply voltages ranging from 1.2V to 3.6V on both the A and B ports, enabling communication between two data buses at different voltage levels. The SN74AVCH2T45 features active bus-hold circuitry, which maintains unused or un-driven inputs at a valid logic state, and is fully specified for partial-power-down applications using Ioff circuitry to prevent damaging current backflow.
Key Specifications
| Parameter | Min | Nom | Max | Unit |
|---|---|---|---|---|
| VCCA (Supply Voltage A) | 1.2 | 3.6 | V | |
| VCCB (Supply Voltage B) | 1.2 | 3.6 | V | |
| VIH (High-Level Input Voltage) - Data Inputs | 0.65*VCCI | 0.7*VCCI | V | |
| VIL (Low-Level Input Voltage) - Data Inputs | 0.35*VCCI | 0.3*VCCI | V | |
| TA (Operating Free-Air Temperature) | -40 | 85 | °C | |
| tPLH (Low-to-High Propagation Delay) | 2.9 | 5.2 | ns | |
| tPHL (High-to-Low Propagation Delay) | 2.9 | 5.2 | ns | |
| RθJA (Junction-to-Ambient Thermal Resistance) - DCT (SSOP) | 183.1 | °C/W | ||
| Package Size - DCU (VSSOP) | 3.10mm × 2.00mm |
Key Features
- Universal Low-Voltage Bidirectional Translation: Supports level-shifting between 1.2V, 1.5V, 1.8V, 2.5V, and 3.3V voltage nodes.
- Active Bus-Hold Circuitry: Holds unused or un-driven inputs at a valid logic state.
- Partial-Power-Down Capability: Ioff circuitry disables outputs to prevent damaging current backflow when powered down.
- VCC Isolation Feature: Ensures both ports are in a high-impedance state if either VCC input is at GND.
- NanoFree Package Technology: Uses the die as the package, reducing size and enhancing performance.
- Direction-Control (DIR) Pin: Activates either B-port outputs or A-port outputs based on logic levels.
Applications
- Asynchronous Communication: Between two data buses operating at different voltage levels.
- Level-Shifting: In mixed-voltage systems where data needs to be translated between different voltage domains.
- Power Management Systems: Where partial-power-down capabilities are essential for energy efficiency.
- Embedded Systems: Requiring compact and efficient logic translation solutions.
Q & A
- What is the voltage range for the supply voltages VCCA and VCCB of the SN74AVCH2T45?
The supply voltages VCCA and VCCB can range from 1.2V to 3.6V.
- What is the purpose of the active bus-hold circuitry in the SN74AVCH2T45?
The active bus-hold circuitry holds unused or un-driven inputs at a valid logic state.
- How does the direction-control (DIR) pin function in the SN74AVCH2T45?
The DIR pin activates either the B-port outputs or the A-port outputs based on its logic levels.
- What is the significance of the Ioff circuitry in the SN74AVCH2T45?
The Ioff circuitry disables the outputs to prevent damaging current backflow when the device is powered down.
- What is the VCC isolation feature in the SN74AVCH2T45?
The VCC isolation feature ensures that if either VCC input is at GND, both ports are put in a high-impedance state.
- What package options are available for the SN74AVCH2T45?
The SN74AVCH2T45 is available in DCT (SSOP), DCU (VSSOP), and YZP (DSBGA) packages.
- What is the operating temperature range for the SN74AVCH2T45?
The operating temperature range is from -40°C to 85°C.
- What is the typical propagation delay for the SN74AVCH2T45?
The typical propagation delay ranges from 2.9ns to 5.2ns depending on the supply voltage.
- What is the significance of NanoFree package technology in the SN74AVCH2T45?
NanoFree package technology uses the die as the package, reducing size and enhancing performance.
- In what scenarios is the SN74AVCH2T45 particularly useful?
The SN74AVCH2T45 is particularly useful in mixed-voltage systems, power management systems, and embedded systems requiring compact and efficient logic translation solutions.
