Texas Instruments SN74LVC2T45YZPRB

Overview

SN74LVC2T45 from Texas Instruments is a dual-bit, dual-supply noninverting bus transceiver enabling bidirectional voltage translation between 1.65 V and 5.5 V rails (e.g., 1.8 V ↔ 3.3 V, 3.3 V ↔ 5 V). It features configurable direction control (DIR referenced to VCCA), ±24-mA output drive at 3.3 V, 4-μA maximum ICC, and VCC isolation. It is used in mixed-voltage I²C, UART, and GPIO interconnects between SoCs and peripherals.

For engineers reviewing the SN74LVC2T45 datasheet, SN74LVC2T45 pinout, SN74LVC2T45 application, or SN74LVC2T45 equivalent, key selection criteria include dual-rail operating range (1.65–5.5 V per supply), DIR input referencing VCCA, Ioff-enabled partial-power-down support, high-speed capability up to 420 Mbps (3.3 V → 5 V), and DSBGA-8 (YZP) package compatibility with space-constrained PCB layouts.

Technical Context

The SN74LVC2T45 implements asynchronous bidirectional level translation using two independent supply domains: VCCA powers the A-port I/Os and DIR input, while VCCB powers the B-port I/Os. Direction is controlled solely by the logic level on DIR-high enables A→B transmission, low enables B→A transmission. Both ports remain active regardless of direction state, requiring defined logic levels on all data pins to avoid excess ICCZ.

VCC isolation ensures both ports enter high-impedance when either VCCA or VCCB = GND, preventing backfeed. Ioff circuitry disables outputs during partial power-down, limiting leakage to ±2 µA per pin. The device supports glitch-free power sequencing-no spurious transitions occur during asymmetric VCCA/VCCB ramp-up or ramp-down.

Key Specifications

Pinout & Package

SN74LVC2T45 is packaged in an 8-pin DSBGA (YZP) measuring 1.5 mm × 0.5 mm, optimized for ultra-compact portable and wearable electronics. The bottom-view ball map aligns with standard micro-BGA assembly processes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply bus transceiver applications.

Compared with TXS0102DCUR and SN74AVC2T244RSWR, SN74LVC2T45 uniquely delivers programmable bidirectional translation with VCC isolation, Ioff, and 420-Mbps capability in a 1.5-mm × 0.5-mm package-making it the sole choice for compact, high-speed, mixed-voltage I²C and GPIO bridges requiring robust power management.

Availability

SN74LVC2T45 is available at Aetrix Electronics and suitable for industrial automation interfaces, portable medical sensors, and consumer wearables requiring stable component supply, long-term lifecycle support, and verified DSBGA-8 assembly compatibility.

Supply support for SN74LVC2T45 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in precision analog, power management, and interface solutions.

SN74LVC2T45 belongs to TI's LVC logic family, designed specifically for low-voltage, mixed-supply system interfacing-emphasizing voltage translation, power sequencing resilience, and ultra-small packaging for next-generation portable and industrial electronics.

FAQ

What is the function of the DIR pin on the SN74LVC2T45?

The DIR (direction) pin on the SN74LVC2T45 controls data flow direction and is referenced to VCCA. When DIR is high, data passes from the A port to the B port; when DIR is low, data flows from B to A. It does not enable/disable outputs-both ports remain electrically active regardless of DIR state, requiring defined logic levels on all I/Os to avoid excessive ICCZ. This behavior is explicitly defined in the Function Table (Table 7-1) of the SN74LVC2T45 datasheet.

Can SN74LVC2T45 translate between 1.8 V and 5 V rails?

Yes, SN74LVC2T45 supports translation between 1.8 V and 5 V rails: VCCA may be set to 1.8 V while VCCB is set to 5 V (or vice versa), as both supplies operate independently across 1.65 V to 5.5 V. The datasheet confirms 75 Mbps operation for 1.8 V translation and lists absolute maximum ratings up to 6.5 V, ensuring robustness. Real-world use cases include interfacing 1.8-V sensors to 5-V microcontrollers in industrial monitoring systems.

Does SN74LVC2T45 support hot-swap or partial-power-down operation?

Yes, SN74LVC2T45 supports partial-power-down via its Ioff feature: when either VCCA or VCCB is at GND, both ports enter high-impedance with leakage limited to ±2 µA. This prevents back-current flow and protects upstream devices. The VCC isolation feature complements this by forcing high-Z on both sides if one rail collapses-critical for hot-plug modules and battery-backed subsystems where rails power up/down asynchronously.

What is the package type and size of SN74LVC2T45?

SN74LVC2T45 is offered in the YZP package: an 8-ball, 1.5-mm × 0.5-mm DSBGA (Die Size Ball Grid Array) with 0.4-mm ball pitch. This NanoFree™ package eliminates the need for wire bonds and leadframes, reducing parasitic inductance and enabling ultra-dense layouts. Its dimensions and thermal metrics (RθJB = 10.8°C/W) are specified in Section 11 of the SN74LVC2T45 datasheet and validated for reflow-compatible assembly.

How does SN74LVC2T45 handle power supply sequencing?

SN74LVC2T45 guarantees glitch-free operation during asymmetric power supply sequencing: VCCA and VCCB may be powered up or down in any order without causing spurious output transitions. This is achieved through internal circuit design that decouples input sampling from supply ramp states. As confirmed in Section 7.3.5, such immunity prevents false data bits, unintended peripheral resets, or erroneous configuration writes in systems with staggered rail activation.