Texas Instruments SN74LVCC3245APW

Overview

SN74LVCC3245APW from Texas Instruments is an octal noninverting bus transceiver with dual supply rails (VCCA: 2.3–3.6 V; VCCB: 3–5.5 V), enabling bidirectional level translation between 2.5/3.3 V and 5 V systems. It features 3-state outputs, direction control (DIR), active-low output enable (OE), and robust power sequencing. Used in ultrasound scanners and string inverters for reliable inter-bus communication across voltage domains.

For engineers reviewing the SN74LVCC3245APW datasheet, SN74LVCC3245APW pinout, SN74LVCC3245APW application, or SN74LVCC3245APW equivalent, key selection criteria include VCCA/VCCB supply independence, Ioff partial-power-down protection, VCC isolation behavior (<100 mV threshold), 24 mA drive strength at 3 V, and TSSOP-24 package compatibility with high-density PCB layouts.

Technical Context

The SN74LVCC3245APW implements asynchronous bidirectional data flow controlled by DIR, with OE enabling full 3-state isolation of both A and B ports. Control logic (DIR, OE) is referenced to VCCA, ensuring consistent timing and threshold behavior regardless of VCCB level.

Its dual-rail architecture supports simultaneous operation across mismatched voltage domains - e.g., 3.3 V microcontroller (A port) interfacing to 5 V peripheral (B port) - while maintaining glitch-free transitions during power-up/down sequences and enforcing high-impedance states when either VCCA or VCCB falls below 100 mV.

Key Specifications

Pinout & Package

Packaged in a 24-pin TSSOP (PW), the SN74LVCC3245APW measures 7.8 mm × 6.4 mm with 0.65 mm lead pitch, optimized for automated assembly and thermal performance (RθJA = 100.6 °C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional level translation applications.

Compared with SN74AVC8T245RHLR and TXB0308RGER, the SN74LVCC3245APW uniquely supports true 5 V B-port operation, provides hardware-enforced VCC isolation, delivers 24 mA drive, and maintains deterministic DIR-controlled directionality - making it the only option among the three qualified for 3.3 V ↔ 5 V industrial power electronics interfaces.

Availability

SN74LVCC3245APW is available at Aetrix Electronics and suitable for ultrasound scanner interfaces, string inverter control systems, and single-board computer expansion requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for SN74LVCC3245APW 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 leader delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The SN74LVCC3245APW belongs to TI's LVCC logic family, engineered specifically for robust bidirectional voltage translation in safety-critical and high-reliability power conversion and medical imaging systems.

FAQ

What voltage ranges does the SN74LVCC3245APW support on its A and B ports?

The SN74LVCC3245APW supports 2.3 V to 3.6 V on the A port (VCCA) and 3 V to 5.5 V on the B port (VCCB). This allows reliable bidirectional translation between common logic families such as 2.5 V/3.3 V microcontrollers and 5 V peripherals. The control inputs DIR and OE are referenced to VCCA, ensuring stable operation across the full VCCA range. SN74LVCC3245APW maintains specified VOH/VOL and timing performance across these ranges per TI's SCAS585R datasheet.

How does the VCC isolation feature work in the SN74LVCC3245APW?

The VCC isolation feature in the SN74LVCC3245APW disables all I/O outputs and forces them into high-impedance state when either VCCA or VCCB falls below 100 mV or is left floating. This prevents bus contention and unintended signal injection during power-up, brownout, or hot-swap conditions. The behavior is hardware-implemented and requires no external circuitry. SN74LVCC3245APW guarantees this response across –40 °C to +85 °C, making it suitable for industrial inverters and medical equipment with stringent fault-safety requirements.

Can the SN74LVCC3245APW be used without connecting both VCCA and VCCB simultaneously?

Yes - the SN74LVCC3245APW supports independent power sequencing: either VCCA or VCCB may be powered first, last, or held at 0 V while the other remains active. Its glitch-free architecture ensures no spurious output transitions occur during such transitions. When one supply is <100 mV, both ports enter high-Z. SN74LVCC3245APW is explicitly designed for partial-power-down use cases, with Ioff leakage limited to ±2 μA, satisfying JESD 78 and JEDEC 17 standards for system-level power management.

What is the maximum data rate supported by the SN74LVCC3245APW?

The SN74LVCC3245APW achieves ≤9.4 ns propagation delay (A→B, VCCA=2.5 V, VCCB=3.3 V), supporting reliable operation up to ~100 MHz for short trace lengths with proper termination. Switching characteristics are characterized across VCCA/VCCB combinations including 3.6 V/5.5 V, where tPHL/tPLH remain ≤6 ns. Real-world data rate depends on load capacitance, PCB layout, and signal integrity design - TI recommends CL ≤50 pF and controlled-impedance routing. SN74LVCC3245APW's 24 mA drive strength helps maintain edge rates under typical bus loading.

Does the SN74LVCC3245APW require external pull-up or pull-down resistors on DIR or OE?

No - the SN74LVCC3245APW has no internal weak pull-ups or pull-downs on DIR or OE; these are standard CMOS inputs referenced to VCCA. External biasing is required if the controlling logic cannot guarantee valid VIH/VIL levels during power-up or reset. For robust operation, tie DIR to VCCA (for A→B mode) or GND (for B→A mode) and OE to GND (enabled) or VCCA (disabled) via appropriate series resistance if driven by open-drain sources. SN74LVCC3245APW datasheet Section 5.3 specifies VIH = 2.0 V min and VIL = 0.8 V max at VCCA = 3.3 V, defining the required voltage margins.