NXP Semiconductors PCA9306JKZ

Overview

PCA9306JKZ from NXP Semiconductors is a dual bidirectional I²C-bus and SMBus voltage-level translator with enable control, supporting 1.0 V–3.6 V (VREF1) and 1.8 V–5.5 V (VREF2) domains, <1.5 ns propagation delay, 3.5 Ω ON-state resistance, and operation up to >2 MHz in Fast-mode Plus systems. It enables seamless interconnection between low-voltage microcontrollers (e.g., 1.8 V ARM cores) and higher-voltage peripherals (e.g., 3.3 V sensors or EEPROMs) without direction pins.

For engineers reviewing the PCA9306JKZ datasheet, PCA9306JKZ pinout, PCA9306JKZ application, or PCA9306JKZ equivalent, this page delivers verified electrical parameters, X2SON8 package layout, real-world I²C bus translation use cases, and two validated alternative parts with documented functional and application differences.

Technical Context

The PCA9306JKZ implements a passive MOSFET-based bidirectional clamping architecture with dual independent translation channels (SCL1↔SCL2, SDA1↔SDA2), where voltage translation direction is determined by instantaneous rail voltages-not control signals. Its EN input must be biased to VREF2 (≥1 V above VREF1) to activate low-impedance conduction.

Unlike buffered repeaters (e.g., PCA9517A), the PCA9306JKZ provides no bus capacitance isolation when enabled-only high-impedance isolation when disabled. It supports mixed-speed I²C buses (e.g., 100 kHz slave + 400 kHz controller), but system frequency is constrained by RC time constants and added propagation delay.

Key Specifications

Pinout & Package

PCA9306JKZ uses the X2SON8 package (SOT2015-1): 1.35 mm × 1.0 mm body, 0.32 mm height, 8-terminal no-lead construction with wettable flank terminals for automated optical inspection (AOI).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C voltage-level translation applications.

Compared with PCA9306DCU and PCA9306JK, the PCA9306JKZ offers identical translation performance and package dimensions but guarantees full NXP traceability, AEC-Q200-aligned packaging, and direct support through NXP's industrial quality assurance program-critical for long-lifecycle embedded deployments.

Availability

PCA9306JKZ is available at Aetrix Electronics and suitable for industrial sensor hubs, automotive body control modules, wearable health monitors, and server management controllers requiring stable component supply across extended product lifecycles.

Supply support for PCA9306JKZ 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

NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with core expertise in interface, power management, and RF technologies.

The PCA9306JKZ belongs to NXP's I²C level translation portfolio, engineered specifically to simplify mixed-voltage system integration in resource-constrained embedded designs where space, power, and timing margins are critical.

FAQ

What is the minimum voltage difference required between VREF1 and VREF2 for reliable operation of the PCA9306JKZ?

The PCA9306JKZ requires VREF2 to be at least 1.0 V higher than VREF1 for optimal clamping behavior and robust level translation. For example, with VREF1 = 1.8 V, VREF2 must be ≥2.8 V. This ensures sufficient gate drive for internal MOSFET switches and prevents incomplete turn-on that could cause signal degradation or timing violations in I²C communication.

Can the PCA9306JKZ translate between 1.0 V and 5.0 V I²C buses, and what design considerations apply?

Yes, the PCA9306JKZ supports 1.0 V ↔ 5.0 V translation per its datasheet specifications. Critical design considerations include: (1) biasing EN to 5.0 V (not 1.0 V), (2) using separate pull-up resistors on each side (1.0 V side to VREF1, 5.0 V side to VREF2), and (3) verifying that the 1.0 V device's VOL remains ≤0.1 × VREF1 to ensure valid LOW detection on the 5.0 V side. The PCA9306JKZ itself imposes no additional voltage drop beyond its 3.5 Ω Ron.

Does the PCA9306JKZ require external pull-up resistors, and how are their values selected?

Yes, the PCA9306JKZ requires external pull-up resistors on both SCL1/SDA1 (to VREF1) and SCL2/SDA2 (to VREF2). Resistor values depend on bus capacitance, driver sink current, and target speed. For 400 kHz operation with 10 mA sink capability and 20 pF total capacitance, typical values are 2.2 kΩ on the 3.3 V side and 1.0 kΩ on the 1.8 V side. Table 12 in the PCA9306JKZ datasheet provides validated minimum values for common voltage combinations and drive strengths.

How does the EN pin function in the PCA9306JKZ, and what happens when it is left floating?

The EN pin is an active-HIGH enable input that must be pulled to VREF2 (not VREF1) via a high-value resistor (e.g., 200 kΩ) to activate translation. If left floating, EN defaults to LOW due to internal leakage, placing the device in high-impedance isolation mode-disconnecting SCL1↔SCL2 and SDA1↔SDA2. This state prevents bus contention but halts all communication; therefore, EN must never be unconnected in operational designs.

Is the PCA9306JKZ compatible with Fast-mode Plus (1 MHz) I²C systems, and what limits its maximum frequency?

Yes, the PCA9306JKZ supports Fast-mode Plus I²C (up to >2 MHz) per its datasheet. Maximum achievable frequency depends on external factors: total bus capacitance (PCB traces + device inputs), pull-up resistor values, and driver sink strength. With 15 mA drivers, 10 pF capacitance, and optimized 1.0 kΩ pull-ups, 1 MHz operation is reliably achieved. Propagation delay (<1.5 ns) is not the limiting factor-the RC time constant of the translated bus segment dominates timing margins.