NXP Semiconductors PCA9515D,112

Overview

PCA9515D,112 from NXP Semiconductors is a BiCMOS I²C-bus repeater IC that buffers both SDA and SCL lines to isolate two 400 pF I²C segments, enabling bus extension, voltage-level translation (3.3 V ↔ 5 V), and mixed-speed operation (100 kHz/400 kHz). It features active-HIGH enable, open-drain I/O, and operates from 3.0 V to 3.6 V.

For engineers reviewing the PCA9515D,112 datasheet, PCA9515D,112 pinout, PCA9515D,112 application, or PCA9515D,112 equivalent, this device is critical for I²C system scalability-especially when addressing bus capacitance limits, multi-voltage domain interfacing, arbitration-aware signal buffering, and robust enable-controlled isolation during power-up sequencing.

Technical Context

The PCA9515D,112 implements dual bidirectional open-drain buffers with static offset-based input thresholding (VILc = +0.4 V) to prevent lock-up during contention, unlike shifting-based repeaters. Its internal pull-downs set VOL ≈ 0.52 V, and the 70 mV VOL−VILc margin ensures reliable low-level propagation across arbitration events.

It supports Standard-mode (100 kHz) and Fast-mode (400 kHz) I²C-bus devices, maintains clock stretching transparency, and requires independent pull-up resistors on both sides. The EN pin must transition only in full bus idle states to avoid hanging the I²C protocol.

Key Specifications

Pinout & Package

PCA9515D,112 is supplied in SO8 package (SOT96-1), 3.9 mm body width, 1.27 mm pitch, with 8 leads. Pin 1 is n.c., and all pins are arranged as shown in Figure 2 of the datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9515DP,118, PCA9515D,112 offers better thermal dissipation in SO8; compared with PCA9515A,112, it trades supply flexibility for proven stability in fixed 3.3 V systems and simpler enable sequencing.

Availability

PCA9515D,112 is available at Aetrix Electronics and suitable for industrial automation, sensor hub expansion, multi-voltage embedded controllers, and I²C-based power management systems requiring stable component supply and long-term sourcing continuity.

Supply support for PCA9515D,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 company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The PCA9515D,112 belongs to NXP's I²C-bus repeater product line, designed specifically to solve bus capacitance, voltage translation, and mixed-speed interoperability challenges in resource-constrained embedded systems.

FAQ

What is the function of the EN pin on the PCA9515D,112?

The EN pin on the PCA9515D,112 is an active HIGH repeater enable input with an internal pull-up resistor. When asserted HIGH, it activates both SDA and SCL buffers; when LOW, it disables buffering and places the I/O pins in high-impedance state. It must only transition during full bus idle states-never mid-transaction-to prevent I²C bus hang. The PCA9515D,112 datasheet specifies strict timing requirements: EN must be stable ≥100 ns before START and held ≥100 ns after STOP.

Can the PCA9515D,112 be used to connect a 3.3 V microcontroller to a 5 V I²C sensor?

Yes, the PCA9515D,112 supports 5.5 V tolerance on all I²C-bus pins (SCL0, SCL1, SDA0, SDA1) and EN, allowing direct connection between 3.3 V and 5 V domains without external level-shifting components. Its BiCMOS architecture maintains signal integrity and protocol compliance-including arbitration and clock stretching-across voltage boundaries. The PCA9515D,112 achieves this while operating from a 3.0–3.6 V VCC supply, making it ideal for mixed-voltage I²C systems.

Does the PCA9515D,112 support Fast-mode Plus (1 MHz) I²C operation?

No, the PCA9515D,112 is rated for up to 400 kHz clock frequency-supporting Standard-mode (100 kHz) and Fast-mode (400 kHz) I²C-bus devices only. Its propagation delays (tPHL up to 170 ns, tPLH up to 78 ns) and internal buffer design are not optimized for 1 MHz timing margins. For Fast-mode Plus applications, designers should evaluate dedicated 1 MHz repeaters or consider alternative architectures; the PCA9515D,112 datasheet explicitly limits operation to 0 Hz–400 kHz.

What happens to the PCA9515D,112 I²C pins when VCC is unpowered?

When VCC = 0 V, the PCA9515D,112 I²C pins (SCL0, SCL1, SDA0, SDA1) enter a high-impedance state but exhibit elevated input capacitance (~200 pF), which can load an active bus and degrade signal integrity. This behavior is documented in Section 1 "General description" and Table 5 of the PCA9515D,112 datasheet. For applications where the repeater may be unpowered while buses remain live, the PCA9515A variant is recommended-it reduces Ci to <10 pF under the same condition.

Is the PCA9515D,112 pin-compatible with the PCA9515DP,118?

Yes, the PCA9515D,112 (SO8/SOT96-1) and PCA9515DP,118 (TSSOP8/SOT505-1) share identical pin numbering, pin functions, and electrical specifications-only the package footprint differs. Both use the same 8-pin arrangement: Pin 1 (n.c.), Pin 2 (VCC), Pin 3 (SCL0), Pin 4 (SCL1), Pin 5 (SDA0), Pin 6 (SDA1), Pin 7 (GND), Pin 8 (EN). Layout changes are required for package substitution, but no schematic or firmware modifications are needed for the PCA9515D,112 to PCA9515DP,118 migration.