NXP Semiconductors PCA9509PDP,118

Overview

PCA9509PDP,118 from NXP Semiconductors is a low-power, bidirectional I²C-bus/SMBus level-translating repeater with dual independent supplies (VCC(A): 0.8–2.0 V; VCC(B): 2.3–5.5 V), enabling 0.9 V processor buses to interoperate with 3.3 V/5 V peripherals while supporting arbitration and clock stretching. It buffers both SDA and SCL lines, extends bus capacitance tolerance to 400 pF on the high-voltage side, and features lock-up-free operation via offset LOW logic on port A.

For engineers reviewing the PCA9509PDP,118 datasheet, PCA9509PDP,118 pinout, PCA9509PDP,118 application, or PCA9509PDP,118 equivalent, this device addresses critical low-voltage interface challenges in portable, battery-powered, and mixed-voltage embedded systems-especially where standby current (<22 μA), bus isolation, and noise-immune edge rate control are design priorities.

Technical Context

The PCA9509PDP,118 implements asymmetric voltage translation using open-drain buffers with distinct input thresholds and output pulldown voltages per port: port A uses ~0.15VCC(A) input threshold and ~0.2VCC(A) output LOW to prevent lock-up; port B complies fully with SMBus/I²C voltage levels (VIL = 0.3VCC(B), VOL ≤ 0.2 V at 30 mA). Its internal power-up circuit enforces driver enable only when VCC(A) > 0.7 V and VCC(B) > 1.7 V.

Propagation delays are asymmetric and supply-dependent: tPHL (A→B) is 52–226 ns, tPLH2 (A→B, measured from 0.15VCC(A) to 0.5VCC(B)) is 61–266 ns, and falling slew rates are controlled at 0.007–0.036 V/ns (port A) and 0.02–0.1 V/ns (port B) to suppress reflections and undershoot without external components.

Key Specifications

Pinout & Package

TSSOP8 package (SOT505-1), 3 mm body width, lead pitch 0.65 mm, thermally enhanced for low-power operation in space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCA9509PDP,118, the PCA9515APW,118 and TCA9517DGKR lack true sub-1 V port A support, EN-controlled ultra-low-power mode, and lock-up immunity - making PCA9509PDP,118 uniquely suited for next-generation ultra-low-power embedded systems with heterogeneous voltage domains.

Availability

PCA9509PDP,118 is available at Aetrix Electronics and suitable for mobile sensor hubs, industrial PMIC monitoring, wearable health monitors, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for PCA9509PDP,118 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 deep expertise in interface, power management, and embedded processing technologies.

The PCA9509PDP,118 belongs to NXP's I²C/SMBus repeater product line, engineered specifically for ultra-low-power, mixed-voltage system integration - targeting battery-operated devices and energy-efficient industrial controllers where voltage domain bridging must not compromise timing fidelity or power budget.

FAQ

What is the minimum operating voltage for port A of the PCA9509PDP,118?

The PCA9509PDP,118 supports port A operation down to 0.8 V, with guaranteed functionality at -40 °C ambient. However, system design must minimize ground path resistance to avoid dropping below the 0.72 V power-good threshold under load - especially critical when both outputs drive LOW simultaneously at cold temperatures.

Does the PCA9509PDP,118 support clock stretching and arbitration across voltage domains?

Yes, the PCA9509PDP,118 fully preserves I²C-bus arbitration and clock stretching behavior. Its bidirectional buffering and asymmetric threshold design ensure that stretched clocks and multi-master arbitration signals propagate correctly between port A and port B without corruption or timing violation.

How does the enable (EN) pin affect power consumption and timing of the PCA9509PDP,118?

When EN is LOW, the PCA9509PDP,118 enters standby mode with total current <22 μA. Recovery requires ≥10 μs after EN goes HIGH before valid signal translation resumes - so START conditions must be delayed accordingly to avoid bus hang or data corruption.

Can the PCA9509PDP,118 be used with Fast-mode Plus (Fm+) I²C devices on port B?

Yes - port B drivers sink up to 40 mA, exceeding Fm+ requirements (30 mA). However, pull-up resistor sizing must still accommodate the weakest device on the bus; if Standard-mode parts coexist, pull-up current must remain ≤3 mA to ensure compatibility.

What is the maximum allowable ground offset between port A and port B of the PCA9509PDP,118?

The PCA9509PDP,118 requires ground offset <40 mV to reliably detect port A LOW states (VIL = 0.1VCC(A)). Exceeding this causes misinterpretation of logic levels - particularly problematic at 0.8 V supply where VIL is only 80 mV, leaving minimal noise margin.