NXP Semiconductors PCA9516D,112

Overview

The PCA9516D,112 from NXP Semiconductors (formerly Philips Semiconductors) is a 5-channel bi-directional I²C bus repeater hub designed to extend I²C/SMBus systems beyond the 400 pF capacitance limit. It supports standard- and fast-mode operation (up to 400 kHz), operates from 3.0 V to 3.6 V, features five independent SDA/SCL channel pairs with active-HIGH enable inputs, and enables voltage-level translation between 3.3 V and 5 V buses in mixed-voltage systems.

For engineers reviewing the PCA9516D,112 datasheet, PCA9516D,112 pinout, PCA9516D,112 application, or PCA9516D,112 equivalent, key selection criteria include bus segmentation capability, 5.5 V tolerance on I²C/enable pins, lock-up-free open-drain buffering, propagation delay (tPHL ≤ 170 ns), and support for arbitration and clock stretching across segments.

Technical Context

The PCA9516D,112 implements a static offset-based buffer architecture-each internal repeater uses differentiated input thresholds (VILc = 0.4 VCC max) and output LOW levels (VOL = 0.52 V typ) to prevent lock-up during multi-segment cascading. Its hub logic routes signals without direction control pins, enabling transparent bidirectional data flow on all five SDA/SCL channels.

It integrates five independent open-drain buffers per channel pair, each with internal pull-up resistors on EN1–EN4, and supports dynamic bus isolation: individual channels can be disabled while others remain active, allowing concurrent 100 kHz and 400 kHz operation on separate segments-e.g., isolating a 100 kHz slave while running master and other slaves at 400 kHz.

Key Specifications

Pinout & Package

PCA9516D,112 is supplied in a 16-pin plastic SO package (SOT109-1), 3.9 mm body width, with standard gull-wing lead form for surface-mount assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C bus repeater applications.

Compared with TCA9517DGKR and PCA9515AD,118, the PCA9516D,112 uniquely delivers five independently controllable I²C segments in a single package-enabling complex star topologies, mixed-speed operation, and voltage translation without external components, making it optimal for dense, multi-peripheral industrial and telecom systems.

Availability

PCA9516D,112 is available at Aetrix Electronics and suitable for industrial sensor networks, server management subsystems, medical diagnostics equipment, and telecom baseband modules requiring stable component supply across extended product lifecycles.

Supply support for PCA9516D,112 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 focused on secure connectivity solutions for automotive, industrial, and IoT applications, with roots in Philips Semiconductors' analog and interface IC heritage.

The PCA9516D,112 belongs to NXP's I²C infrastructure portfolio, engineered specifically to solve bus capacitance, voltage translation, and multi-speed isolation challenges in high-density embedded systems.

FAQ

What is the maximum I²C clock frequency supported by the PCA9516D,112?

The PCA9516D,112 supports up to 400 kHz I²C fast-mode operation. However, the actual achievable system frequency depends on total propagation delay (tPHL ≤ 170 ns) and external bus loading. In practice, designs with >200 pF per segment or long trace lengths may require derating to 100–300 kHz to meet setup/hold timing. The PCA9516D,112 itself does not limit speed beyond its specified AC characteristics.

Can the PCA9516D,112 be used to connect 3.3 V and 5 V I²C buses?

Yes - the PCA9516D,112 has 5.5 V tolerant SDA, SCL, and enable pins, allowing direct connection to 5 V buses while operating from a 3.3 V supply (VCC = 3.0–3.6 V). No external level-shifting components are required. This makes the PCA9516D,112 ideal for bridging legacy 5 V peripherals with modern 3.3 V controllers in mixed-voltage systems.

Why can't multiple PCA9516D,112 devices be cascaded in series?

The PCA9516D,112 uses a static offset architecture where "buffered LOW" output (VOL ≈ 0.52 V) is intentionally higher than the "regular LOW" input threshold (VILc ≤ 0.4 VCC). When fed into a second PCA9516D,112, this buffered level falls below the second device's recognition threshold, halting propagation. This design prevents lock-up but prohibits daisy-chaining - only star-topology connections are supported.

How does the PCA9516D,112 handle I²C arbitration and clock stretching?

The PCA9516D,112 fully preserves I²C arbitration and clock stretching behavior across all five channels. Its open-drain buffers replicate bus contention events transparently: when a slave holds SCL LOW, the PCA9516D,112 propagates the condition to the master side, and vice versa. This ensures protocol-compliant multi-master operation and accurate timing handshaking without modification to host or peripheral firmware.

What is the purpose of the VOL–VILc specification (70 mV) in the PCA9516D,112 datasheet?

The 70 mV guaranteed difference between output LOW voltage (VOL) and subsequent input LOW threshold (VILc) ensures robust noise immunity and prevents metastability during repeated LOW-level transitions across segments. In the PCA9516D,112, this margin allows reliable detection of arbitration pulses and clock-stretching signals even under worst-case voltage drop and temperature variation - a critical design feature for deterministic I²C repeater operation.