SN74LVC2G241DCUR

The SN74LVC2G241DCUR is a dual non-inverting buffer and line driver with 3-state outputs, manufactured by Texas Instruments as part of the 74LVC logic family. Designed for operation from 1.65 V to 5.5 V, this device is specifically engineered to improve the performance and density of 3-state memory-address drivers, clock drivers, and bus-oriented receivers and transmitters. The device is organized as two independent 1-bit line drivers, each with its own output-enable control: the 1OE input is active-low and the 2OE input is active-high. When the output-enable condition is met, data passes from the A input to the Y output; when disabled, the output enters the high-impedance (3-state) state, allowing safe bus sharing among multiple devices. A key advantage of this device is its over-voltage tolerant input structure, which accepts signals up to 5.5 V regardless of the VCC supply level. This enables the SN74LVC2G241DCUR to function as a down-translator, converting higher-voltage logic levels to the VCC rail voltage — a valuable feature in mixed-voltage systems where a 3.3 V or 5 V bus must interface with a lower-voltage controller. The integrated Ioff circuitry ensures that outputs are disabled during power-up or power-down, preventing damaging backflow current and supporting live insertion and partial-power-down applications. Packaged in a compact VSSOP-8 (DCU) footprint of only 2.0 x 3.1 mm, the device minimizes board area while delivering robust ±24-mA output drive at 3.3 V and a propagation delay of just 4.1 ns.

The SN74LVC2G241DCUR operates through three functional subsystems:

1. Non-Inverting Buffer Core: Each of the two channels contains a CMOS non-inverting buffer stage. When the corresponding output-enable pin is in the active state (1OE = low for Channel 1; 2OE = high for Channel 2), the buffer passes the logic level at the A input directly to the Y output without inversion. The CMOS push-pull output stage provides symmetric source (IOH) and sink (IOL) current capability — up to ±24 mA at 3.3 V — ensuring strong signal drive even across long PCB traces or multiple loads. The balanced output architecture minimizes duty-cycle distortion in clock distribution applications.

2. 3-State Output Enable Control: Each channel features an independent output-enable input. When the enable condition is not met (1OE = high or 2OE = low), the output transistors are both turned off, placing the Y output in a high-impedance (Hi-Z) state. This allows multiple devices to share a common bus without contention. During power-up or power-down transients, the Ioff circuitry ensures the outputs remain in Hi-Z, preventing back-drive current from flowing through the device and protecting downstream components. Designers should tie 1OE to VCC via a pull-up resistor and 2OE to GND via a pull-down resistor to guarantee the Hi-Z state during supply transitions.

3. Over-Voltage Tolerant Input and Down-Translation: The input stage is designed to accept voltages up to 5.5 V independently of the VCC supply. When VCC is set to a lower voltage (e.g., 1.8 V or 2.5 V) while the input signal originates from a higher-voltage domain (e.g., 3.3 V or 5 V), the device clamps and level-shifts the input to the VCC logic level at the output. This down-translation capability eliminates the need for external level-shifter ICs in mixed-voltage system designs. The input clamp diodes also provide a defined path for negative undershoots up to -50 mA (IIK), protecting the thin-oxide CMOS gates from damage.

• AV receivers and home theater systems: Buffers audio/video control signals between DSPs and HDMI/SPDIF interfaces with 3-state bus sharing
• Desktop and notebook PCs: Drives memory address lines and clock distribution networks with low propagation delay and high drive strength
• Portable media players and mobile internet devices: Level-shifts signals between 1.8 V/2.5 V processors and 3.3 V peripherals using down-translation capability
• GPS personal navigation devices: Buffers communication bus signals between GPS module and host processor with minimal power consumption (10 µA ICC)
• Embedded PCs and industrial systems: Provides bus isolation and signal buffering with Ioff live-insertion support for hot-swap modules