NXP USA Inc. PCA9306D,118

Summary of PCA9306D,118 Dual-Channel Bidirectional I²C-Bus and SMBus Voltage Level Converter

NXP’s PCA9306D,118 is a versatile, dual bidirectional voltage-level translator designed for I²C and SMBus applications. Its primary function is to seamlessly interface devices or systems operating at different voltage levels, supporting communication between them without the need for explicit direction control. With support for voltage translation between 1.0 V and 5.5 V across two channels and its enable (EN) function, PCA9306D,118 offers engineers a universal solution for mixed-voltage designs. This device operates reliably across a wide ambient temperature range, from -40°C to +105°C, making it suitable for demanding environments. The PCA9306D,118 comes in compact SO8 footprints, facilitating design in space-constrained applications.

Key features include:

Voltage level translation between common rails (1.0V, 1.2V, 1.8V, 2.5V, 3.3V, and 5V)

2-channel bidirectional translation for SDA and SCL bus lines

Compatible with Standard-mode, Fast-mode, and Fast-mode Plus I²C/SMBus devices

Minimal propagation delay (<1.5 ns max), supporting rapid bus transactions

No direction pin required; automatic sensing and translation

High ESD protection (>2000 V HBM, >1000 V CDM)

This breadth of operational parameters and robustness present the PCA9306D,118 as an ideal candidate for embedded systems, industrial control, consumer electronics, and communication interface designs.

-

Electrical Specifications and Functional Features of PCA9306D,118

The PCA9306D,118 operates as a bidirectional voltage-level translator with integrated switches connecting SDA and SCL bus lines between two voltage domains. When the EN input is set HIGH, voltage translation is enabled and allows data transfer between SCL1/SDA1 and SCL2/SDA2. Setting EN LOW isolates the two sides, placing the bus lines in high-impedance states to prevent unintended interaction.

Its open-drain architecture necessitates external pull-up resistors on both bus sides, which must be sized per system requirements (drive strength, logic thresholds, and target operating frequency). With a low ON-state resistance (3.5 Ω typical), the device introduces minimal distortion and is optimized for signal integrity in timing-sensitive applications. PCA9306D,118 supports various voltage translation permutations, such as converting from 1.0V to 3.3V or from 3.3V to 5V, accommodating a wide range of legacy and modern devices.

The translator supports frequencies greater than 2 MHz, but the actual maximum depends on RC time constants influenced by attached components, PCB layout, and chosen resistor values. The device’s lock-up free operation and symmetrical channel design ensure consistent, reliable performance across both translation paths—a significant improvement over discrete transistor-based translation solutions. Additionally, PCA9306D,118 provides enhanced ESD protection, safeguarding sensitive low-voltage components during manufacturing and in operating environments.

-

Pin Layout and Packaging Choices for PCA9306D,118

PCA9306D,118 is available in industry-standard 8-lead SO8, TSSOP8, VSSOP8, XQFN8, XSON8, and X2SON8 packages, offering compatibility with automated assembly and various form-factor constraints. Pin configurations are designed for streamlined PCB trace routing, supporting efficient board layouts in densely populated circuits.

The device features the following pins:

SCL1, SDA1: Bus lines for the lower-voltage domain

SCL2, SDA2: Bus lines for the higher-voltage domain

EN: Enable input, controlling operational state

VREF1: Reference for lower voltage domain

VREF2: Reference for higher voltage domain

GND: Ground

Each package option supports compatibility with existing footprints from other manufacturers, simplifying redesign or pin-for-pin replacement scenarios. PCB footprint guidelines and solder mask recommendations are provided for optimal mounting and electrical performance across package types.

-

Usage Recommendations for PCA9306D,118

Implementing PCA9306D,118 in system designs involves key considerations for voltage reference selection, pull-up resistor sizing, and achieving desired I²C/SMBus operating frequency. For robust bidirectional translation, VREF2 (higher side) should be at least 1V greater than VREF1 (lower side). EN input should follow the higher logic level to guarantee reliable switching.

Engineers should size pull-up resistors based on driver current capability, voltage thresholds, and required bus speed. Tables provide minimum resistor values for typical sink currents (3 mA, 10 mA, 15 mA), which ensure voltage levels remain within specification and signal rise/fall times support bus bandwidth requirements.

To maximize operational frequency:

Minimize PCB trace lengths and total node capacitance

Optimize resistor values for shortest practical rise/fall times

Place PCA9306D,118 close to processor and other critical devices

Limit stub and connector lengths to reduce unwanted reflections

Potential engineering scenarios include bridging two microcontroller domains operating at differing logic levels, or isolating a 400 kHz main bus while keeping a 100 kHz peripheral isolated during specific operation modes.

-

PCB Layout, Soldering Methods, and Assembly Guidelines for PCA9306D,118

PCA9306D,118 packages are compatible with industry-standard surface-mount soldering techniques, including wave and reflow soldering. Reflow processes, suited for fine-pitch and high-density designs, should follow NXP’s temperature profile recommendations and moisture sensitivity precautions according to J-STD-020D. Accurate stencil thickness and solder paste application ensure reliable electrical connections and mechanical stability.

Layout guidelines, including solder land dimensions and mask openings, are provided for all supported package types, assisting PCB designers in developing consistent, manufacturable footprints. Attention to recommended board finishes, solder masks, lead formation, and package placement will further enhance assembly yield and device reliability.

-

Possible Alternative or Replacement Devices for PCA9306D,118

Designers seeking alternatives to PCA9306D,118 may consider the following devices, which offer comparable electrical and mechanical characteristics:

Texas Instruments PCA9306DCU (identical footprint and pinout, functionally equivalent bidirectional I²C/SMBus translator)

NXP PCA9306DC1 (functionally and electrically similar, offered in dark green packaging for specific applications)

NXP PCA9306DC1Z (replacement for discontinued models, same feature set)

NXP PCA9306JK (next-generation replacement for PCA9306GF, SOT2015-1 package)

Each alternative supports the same dual bidirectional translation, voltage range, and package compatibility, enabling seamless interchange in existing designs. These options also simplify procurement and future-proof applications against lifecycle management concerns.

-

Conclusion

: Selecting PCA9306D,118 for Voltage Level Translation Solutions

The PCA9306D,118 from NXP presents a highly adaptable, robust, and easy-to-implement solution for engineers requiring reliable I²C and SMBus voltage-level translation in mixed-signal environments. Its broad voltage compatibility, bidirectional translation without direction control, minimal signal delay, and comprehensive package support distinguish it as a compelling choice for a range of embedded and industrial applications.

With its superior ESD performance, simple implementation in both new and legacy designs, and clear fit within existing PCB layouts—plus the assurance of alternative pin-compatible options—the PCA9306D,118 serves as an invaluable asset for product selection engineers and procurement personnel tasked with creating high-integrity, mixed-voltage electronic assemblies.