Texas Instruments PCA9515BDGKR

Overview

PCA9515BDGKR from Texas Instruments is a dual-channel bidirectional I²C/SMBus repeater IC designed to extend bus capacitance limits and isolate segments in multi-slave systems. It operates from 2.3 V to 3.6 V, supports Standard Mode (100 kHz) and Fast Mode (400 kHz), features active-high enable (EN), open-drain I/O with 5.5-V tolerance, and delivers lockup-free bidirectional buffering for SDA0/SDA1 and SCL0/SCL1 signals - deployed in server backplanes and telecom routers requiring robust inter-IC communication over long PCB traces.

For engineers reviewing the PCA9515BDGKR datasheet, PCA9515BDGKR pinout, PCA9515BDGKR application, or PCA9515BDGKR equivalent, key selection considerations include its 8-pin VSSOP package, 400-pF per-bus capacitance support, voltage-level translation capability between 2.3 V and 5.5 V domains, propagation delay ≤130 ns at 2.5 V, and EN-controlled isolation for power-up sequencing and fault containment.

Technical Context

The PCA9515BDGKR implements two independent BiCMOS open-drain buffer channels, each with hysteresis-based edge detection and CMOS output drivers that replicate low states across isolated bus segments while preserving arbitration, clock stretching, and multi-master compatibility. Its internal power-up control circuit prevents output activation until VCC reaches ≥2.3 V, ensuring glitch-free initialization.

It enables mixed-voltage operation: one side may interface with a 3.3-V master while the other connects to 5-V slaves, using separate pull-up resistors per segment. The device does not support cascaded repeaters due to intentional VOL–VILc offset (≥120 mV) preventing false-low recognition between stages.

Key Specifications

Pinout & Package

PCA9515BDGKR is housed in an 8-pin VSSOP (DGK) package measuring 3.00 mm × 3.00 mm, with exposed pad not electrically connected. Pin 1 is NC (no internal connection); pins 2–3 and 6–7 form mirrored I²C channel pairs; EN (pin 5) controls both channels simultaneously.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9515BDGKR, PCA9517ADGKR provides half the channel count but lower BOM cost for simple extensions, while TCA9517APWR offers identical functionality in a different footprint - neither supports true dual-bus isolation like the PCA9515BDGKR's native two-channel architecture.

Availability

PCA9515BDGKR is available at Aetrix Electronics and suitable for server backplanes, telecom switching equipment, industrial PLCs, and automotive ECU subsystems requiring stable component supply across extended product lifecycles.

Supply support for PCA9515BDGKR 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 company delivering analog and embedded processing solutions, with leadership in precision analog, power management, and interface technologies.

The PCA9515BDGKR belongs to TI's I²C interface and bus repeater product line, engineered specifically to solve signal integrity and voltage-domain bridging challenges in dense, multi-node embedded systems.

FAQ

What is the maximum bus capacitance each side of the PCA9515BDGKR can drive?

The PCA9515BDGKR is specified to support up to 400 pF of total bus capacitance on each isolated segment (Bus 0 and Bus 1). This value aligns with the I²C specification limit and ensures reliable operation at both 100 kHz and 400 kHz. Exceeding 400 pF per side risks violating rise-time requirements and may cause communication failures - the PCA9515BDGKR itself does not increase this limit but enables splitting a larger total capacitance across two compliant segments.

Can the PCA9515BDGKR be used with a 5-V VCC supply?

No, the PCA9515BDGKR requires VCC between 2.3 V and 3.6 V per its Recommended Operating Conditions. While its I/O pins tolerate up to 5.5 V, applying 5 V to VCC violates absolute maximum ratings and will damage the device. For 5-V systems, use the VCC-supply rail within spec and rely on the 5.5-V I/O tolerance to interface with 5-V peripherals - the PCA9515BDGKR itself must be powered from 2.3–3.6 V.

Does the PCA9515BDGKR support I²C Fast Mode Plus (1 MHz)?

No, the PCA9515BDGKR is rated only for Standard Mode (100 kHz) and Fast Mode (400 kHz). Its propagation delay (max 130 ns) and transition times are not characterized for 1 MHz operation, and the datasheet makes no claim of Fast Mode Plus compliance. Using it beyond 400 kHz risks setup/hold violations and unreliable arbitration - for 1 MHz designs, consider purpose-built Fast Mode Plus repeaters or retiming solutions.

How does the EN pin behave during power-up?

PCA9515BDGKR includes an internal pull-up on the EN pin to VCC, so it defaults to high (enabled) once VCC reaches a valid level (≥2.3 V). A dedicated power-up control circuit holds outputs in high-impedance until VCC stabilizes, preventing glitches. If external control is needed, drive EN low before VCC ramps, or add a RC delay to coordinate with system reset sequencing - floating EN is acceptable due to the internal pull-up.

Is cascading multiple PCA9515BDGKR devices allowed?

No, cascading two or more PCA9515BDGKR devices in series is explicitly prohibited per the datasheet. The device uses a deliberate VOL–VILc offset (≥120 mV) to prevent lockup, meaning the buffered low output (~0.5 V) from one unit falls outside the valid low-input threshold of the next. This design ensures single-stage reliability but blocks multi-hop extension - for longer paths, redesign the topology using star or hub configurations instead of daisy-chaining repeaters.