Texas Instruments PCA9306DCTT

Overview

PCA9306DCTT from Texas Instruments is a dual bidirectional I²C/SMBus voltage-level translator IC enabling seamless communication between 1.2-V and 5-V domains without direction control. It supports standard- and fast-mode I²C (up to 400 kHz), delivers <1.5 ns max propagation delay, features 3.5 Ω typical R_ON, and operates across –40°C to +85°C ambient temperature.

For engineers reviewing the PCA9306DCTT datasheet, PCA9306DCTT pinout, PCA9306DCTT application, or PCA9306DCTT equivalent, key selection criteria include bidirectional level translation capability, EN-controlled isolation, open-drain I/O tolerance up to 5 V, flow-through SSOP-8 pinout, and compatibility with mixed-voltage I²C subsystems in servers, industrial controllers, and embedded computing platforms.

Technical Context

The PCA9306DCTT implements two independent NFET-based pass-gate channels (SCL/SDA) controlled by a single enable input, eliminating need for direction logic. Its internal threshold voltage (~0.6 V) enables automatic low-voltage-side pull-down propagation during translation down (e.g., 3.3 V → 1.8 V).

When EN = high, both channels conduct bidirectionally with minimal R_ON-induced distortion; when EN = low, all I/O pins enter high-impedance state with lockup-free isolation. The device supports asymmetric supply configurations: VREF1 (1.2–3.3 V) and VREF2 (1.8–5.5 V), with strict VREF2 ≥ VREF1 + 0.6 V for reliable operation.

Key Specifications

Pinout & Package

PCA9306DCTT is packaged in an 8-pin SSOP (DCT) measuring 2.95 mm × 4 mm, with flow-through pin arrangement optimized for PCB trace routing and reduced parasitic coupling between SDA/SCL pairs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TCA9617ADGKR and TXS0102DCUR, PCA9306DCTT provides the widest low-voltage support (down to 1.2 V), explicit EN control for deterministic bus segmentation, and optimal R_ON/delay trade-off for 400-kHz industrial I²C systems-making it the preferred choice for mixed-voltage server, telecom, and programmable logic applications requiring predictable isolation behavior.

Availability

PCA9306DCTT is available at Aetrix Electronics and suitable for industrial automation, telecom infrastructure, and embedded computing applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.

Supply support for PCA9306DCTT 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 PCA9306DCTT belongs to TI's precision interface portfolio, engineered specifically for robust, low-latency I²C/SMBus voltage translation in mixed-supply systems where reliability, ESD resilience, and deterministic enable control are critical.

FAQ

What is the minimum VREF1 voltage supported by PCA9306DCTT?

The PCA9306DCTT supports VREF1 as low as 1.2 V, enabling direct interfacing with ultra-low-voltage microcontrollers and FPGAs. This specification is explicitly validated in TI's datasheet Section 6.3 (Recommended Operating Conditions) and confirmed across all package variants including DCT. Operation below 1.2 V risks incomplete FET turn-on and unreliable low-to-high translation.

Can PCA9306DCTT translate between 1.2 V and 5 V simultaneously?

Yes, PCA9306DCTT is fully specified for 1.2-V VREF1 to 5-V VREF2 translation per TI's datasheet Section 1 (Features) and Section 8.1 (Overview). This requires VREF2 ≥ VREF1 + 0.6 V (i.e., 5 V ≥ 1.2 V + 0.6 V), which holds true. The device maintains <1.5 ns propagation delay and 3.5 Ω R_ON under this condition when EN = high and load current ≤64 mA.

Does PCA9306DCTT require external pull-up resistors on both sides of the I²C bus?

Yes, PCA9306DCTT requires external pull-up resistors on both SCL1/SDA1 (low-voltage side) and SCL2/SDA2 (high-voltage side), as it contains no internal pull-ups. The datasheet Figure 9-2 and Section 9.2 specify that pull-ups must be placed on each domain independently to ensure correct logic levels and rise times-especially critical when translating up (e.g., 1.8 V → 5 V).

What happens to SCL1/SDA1 and SCL2/SDA2 pins when EN = low?

When EN = low, PCA9306DCTT places all four I²C pins (SCL1, SDA1, SCL2, SDA2) into a high-impedance state with lockup-free isolation, as documented in Section 1 (Features) and Section 8.1.3. This physically disconnects both bus segments, preventing cross-talk, unintended clock stretching, or bus contention-enabling safe hot-plug of peripheral modules or frequency-domain separation.

Is PCA9306DCTT compatible with SMBus 3.0 or PMBus protocols?

PCA9306DCTT is explicitly SMBus-compatible per its datasheet Section 1 (Features) and supports all SMBus 2.0 electrical requirements-including timeout, alert response, and packet error checking-due to its <1.5 ns propagation delay, 5-V-tolerant I/O, and open-drain architecture. While not tested to SMBus 3.0 spec, its timing and voltage characteristics meet the foundational electrical layer requirements for PMBus implementations operating at ≤400 kHz.