Overview
The SN74LVC4245APWT is an 8-bit (octal) noninverting bus transceiver designed by Texas Instruments. This device is specifically engineered for asynchronous communication between data buses and features two separate supply rails: VCCB for the B port set at 3.3 V and VCCA for the A port set at 5 V. This configuration allows for seamless translation between 3.3-V and 5-V environments, making it ideal for mixed-voltage systems. The device can transmit data from the A bus to the B bus or vice versa, controlled by the direction-control (DIR) input. Additionally, the output-enable (OE) input can be used to isolate the buses when necessary. The control circuitry is powered by VCCA, ensuring efficient and reliable operation.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| VCCA Supply Voltage Range | -0.5 | - | 6.5 | V |
| VCCB Supply Voltage Range | 2.7 | - | 3.6 | V |
| Input Voltage Range (A port) | -0.5 | - | VCCA + 0.5 | V |
| Output Voltage Range (A port) | -0.5 | - | VCCA + 0.5 | V |
| Propagation Delay (A to B) | - | - | 6.3 | ns |
| Continuous Output Current | - | - | ±50 | mA |
| Storage Temperature Range | -65 | - | 150 | °C |
| Package Type | - | - | TSSOP (PW), 24 pins | - |
Key Features
- 8-bit (octal) noninverting bus transceiver with 3-state outputs
- Two separate supply rails: VCCB (3.3 V) and VCCA (5 V) for voltage translation
- Direction-control (DIR) input to control data transmission between A and B buses
- Output-enable (OE) input to isolate the buses
- 24 mA drive at 3-V supply, suitable for heavier loads and longer traces
- Low VIH for 3.3-V to 5-V translation
- CMOS technology with balanced output drive
- Available in TSSOP (PW) package with 24 pins
Applications
The SN74LVC4245APWT is versatile and can be used in a variety of applications where mixed-voltage systems are present. Some common applications include:
- Bus interface applications where output drive or PCB trace length is a concern
- Mixed-voltage systems requiring 3.3-V to 5-V translation
- System logic and LED driver circuits
- Cable modem termination systems
- Servers and data centers with mixed-voltage requirements
- LED displays and other digital signage
Q & A
- What is the primary function of the SN74LVC4245APWT?
The primary function is to act as an 8-bit noninverting bus transceiver with the ability to translate between 3.3-V and 5-V environments.
- What are the supply voltage ranges for VCCA and VCCB?
VCCA ranges from 4.5 V to 5.5 V, and VCCB ranges from 2.7 V to 3.6 V.
- How is data transmission controlled between the A and B buses?
Data transmission is controlled by the direction-control (DIR) input.
- What is the purpose of the output-enable (OE) input?
The OE input is used to disable the device and isolate the buses.
- What is the maximum continuous output current?
The maximum continuous output current is ±50 mA.
- In what package types is the SN74LVC4245APWT available?
The device is available in a TSSOP (PW) package with 24 pins.
- What are some common applications for this device?
Common applications include bus interface applications, mixed-voltage systems, system logic, and LED driver circuits.
- What is the propagation delay for the SN74LVC4245APWT?
The propagation delay is up to 6.3 ns.
- How does the device handle input voltages beyond the specified range?
Input voltages beyond the specified range can cause permanent damage and are not recommended.
- What is the storage temperature range for the SN74LVC4245APWT?
The storage temperature range is from -65°C to 150°C.
