Nexperia USA Inc. NCA9555BY-Q100HP

Overview

NCA9555BY-Q100 from Nexperia is an automotive-grade 16-bit I²C/SMBus GPIO expander with interrupt output, configurable I/O direction, polarity inversion, and internal pull-up resistors. It operates from 1.65 V to 5.5 V, supports −40 °C to +125 °C, delivers 25 mA per output, and features open-drain INT for event-driven wake-up in vehicle body control modules.

For engineers reviewing the NCA9555BY-Q100 datasheet, NCA9555BY-Q100 pinout, NCA9555BY-Q100 application, or NCA9555BY-Q100 equivalent, key selection criteria include I²C Fast-mode (400 kHz) timing compliance, AEC-Q100 Grade 1 qualification, HWQFN24 thermal performance, register-level I/O configuration flexibility, and interrupt latency behavior under bus read acknowledgment cycles.

Technical Context

The device implements two 8-bit port registers (P0 and P1), each paired with dedicated configuration, input, output, and polarity inversion registers - enabling independent direction and logic-level control per I/O. All 16 pins power up as high-impedance inputs with weak internal pull-ups, eliminating external biasing in many automotive sensor/button interfaces.

Its interrupt logic triggers on any edge transition of configured input pins and resets automatically upon reading the corresponding input register or when pin state reverts; the open-drain INT output requires an external pull-up and is synchronized to I²C ACK/NACK timing, making it suitable for low-latency host wake-up without polling overhead.

Key Specifications

Pinout & Package

HWQFN24 (SOT8041-1), 4 × 4 × 0.75 mm, thermally enhanced package with exposed center pad requiring PCB thermal vias for automotive reliability and thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar GPIO expander applications.

Compared with TCA6424AQPWRQ1 and PCA9555DP,118, the NCA9555BY-Q100 uniquely balances AEC-Q100 Grade 1 compliance, integrated pull-ups, and HWQFN24 thermal performance - making it optimal for space-constrained, high-reliability body electronics where register compatibility and interrupt timing predictability are mandatory.

Availability

NCA9555BY-Q100 is available at Aetrix Electronics and suitable for automotive body control modules, infotainment front panels, ADAS camera power sequencing, and electric power steering interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for NCA9555BY-Q100 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

Nexperia is a global semiconductor expert delivering high-performance, reliable components for automotive, industrial, and consumer markets - with leadership in logic, MOSFETs, diodes, and analog solutions.

The NCA9555-Q100 product line targets automotive electronics needing robust, low-pin-count I/O expansion - designed specifically for body control, lighting, and sensor interface applications demanding AEC-Q100 qualification and minimal external components.

FAQ

What is the maximum capacitive load the NCA9555BY-Q100 SDA/SCL pins can drive?

The device supports standard I²C bus capacitance up to 400 pF per line, verified per Fast-mode specifications. Its Schmitt-trigger inputs and integrated noise filters maintain signal integrity even with 300 pF distributed trace capacitance - typical in multi-node automotive harnesses. No external bus buffers are required below this threshold.

How does the interrupt reset behavior interact with repeated-start I²C reads?

INT resets on the ACK/NACK bit following the rising edge of SCL during a read transaction - not on data byte receipt. If a repeated-start occurs before that clock edge, the interrupt remains asserted. This ensures no edge events are lost during rapid register polling, preserving deterministic wake-up timing in safety-critical systems.

Can P0/P1 pins be mixed as inputs and outputs within the same port?

Yes - each of the 16 I/Os is individually configurable via the Configuration register pair (06h/07h). Bit-level control allows P0_0–P0_3 to operate as inputs monitoring switches while P0_4–P0_7 drive LEDs, all within Port 0, without cross-port dependency or timing penalties.

Is the exposed thermal pad of the HWQFN24 package electrically connected?

Yes - the exposed pad is internally connected to GND and must be soldered to the PCB ground plane. Thermal vias beneath the pad are required to meet AEC-Q100 thermal cycling requirements and sustain 25 mA per pin at +125 °C ambient - failure to connect it risks parametric drift and premature failure in automotive duty cycles.