NXP 74LVCH8T245BQ: An 8-Bit Dual-Supply Bidirectional Voltage-Level Translator with 3-State Outputs
In modern electronic systems, it is common to find multiple subsystems operating at different voltage levels. Efficient and reliable communication between these voltage domains is critical, and this is where dedicated level-translator ICs prove indispensable. The NXP 74LVCH8T245BQ is a prime example of such a device, offering a robust solution for bidirectional voltage translation between components.
This IC is an 8-bit bidirectional translator equipped with dual supply rails. Port A is designed to operate with a supply voltage (VCCA) from 1.2 V to 3.6 V, while Port B's supply (VCCB) ranges from 1.2 V to 5.5 V. This wide voltage range allows it to seamlessly bridge the gap between low-voltage processors (e.g., 1.8 V or 2.5 V) and higher-peripherals (e.g., 3.3 V or 5 V), making it incredibly versatile for mixed-voltage PCB designs.
A key feature of this translator is its bidirectional capability. The direction of data flow for all eight bits is controlled by a single Direction Control (DIR) input pin. A high level on DIR allows data to pass from Port A to Port B, and a low level enables transmission from Port B to Port A. This simplifies the control logic required in the system. Furthermore, the device incorporates 3-state outputs and an Output Enable (OE) input. When OE is pulled low, the outputs are active; when OE is high, the outputs are placed in a high-impedance state. This tri-state feature is essential for preventing bus contention in multi-master systems, such as those with shared data buses.
The 'LVCH' in its name denotes its use of advanced CMOS technology, which provides a series of performance benefits. The 74LVCH8T245BQ boasts very low static and dynamic power consumption, which is crucial for battery-powered and energy-sensitive applications. It also features 24 mA balanced output drive, ensuring strong signal integrity even when driving capacitive loads. To protect the sensitive circuitry it connects, the device includes power-off protection, which ensures that when either VCC is at 0 V, all outputs are in a high-impedance state. Additionally, it incorporates bus-hold circuitry on the data inputs, which eliminates the need for external pull-up or pull-down resistors to maintain a defined logic level on unused or floating pins.
Housed in a space-saving DHVQFN24 package, this translator is ideal for modern, compact electronic designs. Its fully symmetrical active-low output enable and direction control make system integration straightforward. Typical applications range from communication interfaces and networking equipment to portable consumer electronics and industrial automation systems.
ICGOOODFIND: The NXP 74LVCH8T245BQ stands out as an exceptionally versatile and robust solution for bidirectional level shifting. Its combination of wide voltage range, bidirectional control with a single pin, 3-state outputs for bus isolation, and integrated bus-hold circuitry makes it a superior choice for designers tackling the challenges of mixed-voltage systems.
Keywords: Level Translator, Bidirectional, 3-State Outputs, Dual-Supply, Bus-Hold.
