Overview
The 74LVX4245MTCX is an 8-bit dual-supply translating transceiver produced by ON Semiconductor. This device is designed to interface between a 5V bus and a 3V bus in mixed voltage environments, making it ideal for applications such as laptop computers that use 3.3V CPUs and 5V peripheral devices. The transceiver features bidirectional data flow controlled by the Transmit/Receive (T/R) input and includes an Output Enable (OE) input to disable both ports when necessary.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| VCCA (Supply Voltage A) | 5.0V ± 0.5V | 4.5V to 5.5V |
| VCCB (Supply Voltage B) | 3.0V to 3.6V | 2.7V to 3.6V |
| Operating Temperature | Free Air Operating Temperature | −40°C to +85°C |
| Input Voltage (VI) | Input Voltage Levels | 0V to VCCA (A Port), 0V to VCCB (B Port) |
| Output Current | Output Source/Sink Current | 24 mA at 5V, 12 mA at 3V |
| Propagation Delay | Propagation Delay Time | 1.0 ns to 10.0 ns |
| Package Type | Package Description | 24-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153 |
Key Features
- Bidirectional interface between 5V and 3V buses
- Control inputs compatible with TTL level
- 5V data flow at A Port and 3V data flow at B Port
- Outputs source/sink 24 mA at 5V bus; 12 mA at 3V bus
- Guaranteed simultaneous switching noise level and dynamic threshold performance
- Implements patented EMI reduction circuitry
- Functionally compatible with the 74 series 245
- 3-STATE outputs for high impedance condition when OE is HIGH
Applications
The 74LVX4245MTCX is suitable for mixed voltage applications where there is a need to interface between 3V and 5V systems. This includes devices such as laptop computers using 3.3V CPUs and 5V LCD displays, and other mixed voltage environments where CMOS devices cannot tolerate I/O levels above their applied VCC.
It solves the issue of 3V ICs being driven by 5V ICs, which can cause current flow and potential damage to the 3V ICs. The device configures two different output levels to handle dual supply interface issues, ensuring safe and efficient data transfer.
Q & A
- What is the primary function of the 74LVX4245MTCX?
The primary function is to act as a bidirectional interface between 5V and 3V buses in mixed voltage environments. - How is the direction of data flow controlled in the 74LVX4245MTCX?
The direction of data flow is controlled by the Transmit/Receive (T/R) input. Transmit (active-HIGH) enables data from A Ports to B Ports, while Receive (active-LOW) enables data from B Ports to A Ports. - What is the purpose of the Output Enable (OE) input?
The Output Enable (OE) input, when HIGH, disables both A and B Ports by placing them in a high impedance condition. - What are the typical operating voltage ranges for VCCA and VCCB?
VCCA operates from 4.5V to 5.5V, and VCCB operates from 2.7V to 3.6V. - What is the maximum output current for the 74LVX4245MTCX?
The outputs can source/sink up to 24 mA at 5V and up to 12 mA at 3V. - What is the propagation delay time for the 74LVX4245MTCX?
The propagation delay time ranges from 1.0 ns to 10.0 ns. - What package types are available for the 74LVX4245MTCX?
The device is available in 24-Lead Thin Shrink Small Outline Package (TSSOP), among other packages. - Is the 74LVX4245MTCX compatible with other logic devices?
Yes, it is functionally compatible with the 74 series 245. - What is the significance of the patented EMI reduction circuitry?
The patented EMI reduction circuitry helps in minimizing electromagnetic interference, ensuring better signal integrity. - How does the 74LVX4245MTCX prevent damage to 3V ICs when interfaced with 5V ICs?
It prevents damage by configuring two different output levels to handle dual supply interface issues, thus avoiding high current flow from the I/O bus to the 3V power supply.
