NXP Semiconductors PCA9704PWJ

Overview

The PCA9704PWJ from NXP Semiconductors is an 18 V tolerant, 8-bit SPI General Purpose Input (GPI) shift register designed for automotive switch monitoring. It features maskable interrupt output, 4.5–5.5 V supply operation, <2.5 µA quiescent current, and TSSOP16 packaging-enabling robust detection of switch state changes in body control modules under harsh electrical conditions including 40 V load dump.

For engineers reviewing the PCA9704PWJ datasheet, PCA9704PWJ pinout, PCA9704PWJ application, or PCA9704PWJ equivalent, this device delivers verified 18 V input tolerance with external 100 kΩ series resistors, programmable interrupt masking per input, open-drain INT output, and daisy-chain SPI support up to 5 MHz-critical for ECU wake-up extension and cyclic biasing in AEC-Q100-compliant systems.

Technical Context

The PCA9704PWJ implements an 8-bit parallel-to-serial shift register architecture synchronized to SPI clock edges: CS falling edge captures input port status into the input status register and clears pending interrupts; first SCLK rising edge loads the shift register; subsequent rising edges shift out GPI data while falling edges sample SDIN. The interrupt logic compares real-time input levels against the stored status register, asserting INT only when unmasked inputs change state and INT_EN is HIGH.

Each GPI pin integrates 18 V breakdown ESD protection with current steering to ground-not VDD-and requires a minimum 100 kΩ series resistor for >5.5 V input applications. Input thresholds are ratiometric (VIL ≤ 0.55×VDD, VIH ≥ 0.8×VDD), with guaranteed 2.5 V LOW threshold at VDD = 4.5 V and 180 mV hysteresis to suppress noise-induced toggling in automotive environments.

Key Specifications

Pinout & Package

PCA9704PWJ is housed in a plastic thin shrink small outline package (TSSOP16) with 4.4 mm body width (SOT403-1), optimized for high-density automotive PCB layouts and reflow compatibility.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit SPI GPI applications.

Compared with MAX7319ETL+ and TCA9534APWR, the PCA9704PWJ uniquely combines 18 V input tolerance with hardware-interrupt masking, INT_EN–controlled power gating, and sub-3 µA quiescent current-making it the only option qualified for cyclic-biasing wake-up extension in AEC-Q100 automotive ECUs.

Availability

PCA9704PWJ is available at Aetrix Electronics and suitable for automotive body control modules, SBC wake port extensions, and industrial panel switch interfaces requiring stable component supply across extended temperature and voltage stress conditions.

Supply support for PCA9704PWJ 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 specializing in secure connectivity solutions for automotive, industrial, and IoT applications-with deep expertise in AEC-Q100-qualified interface ICs.

The PCA9704PWJ belongs to NXP's automotive-grade GPI portfolio, engineered specifically to replace discrete switch-sensing circuits in body electronics and extend wake capabilities of System Basis Chips under ISO 16750-2 stress conditions.

FAQ

What is the maximum input voltage the PCA9704PWJ can tolerate on its IN0–IN7 pins?

The PCA9704PWJ supports up to 18 V on its GPI pins when used with a minimum 100 kΩ external series resistor. This rating covers automotive transients including 40 V load dump, 27 V jump start, and reverse-battery conditions. Without the resistor, absolute maximum input voltage is 6 V per the datasheet limiting values table.

Does the PCA9704PWJ require external pull-up resistors on its interrupt output?

Yes, the PCA9704PWJ features an open-drain INT pin that requires an external pull-up resistor-typically 10 kΩ-to VDD or another logic rail. This configuration enables wired-AND connection of multiple PCA9704PWJ devices to a shared interrupt line, simplifying wake signal consolidation in multi-GPI systems.

How does the INT_EN pin function in the PCA9704PWJ?

The INT_EN pin on the PCA9704PWJ is an active-HIGH control that simultaneously enables both the GPI input circuitry and the INT output driver. When pulled LOW, it disables GPI leakage current and places INT in high-impedance-reducing total system current to <1 µA in cyclic biasing applications where external pull-ups/pull-downs are switched independently.

Can multiple PCA9704PWJ devices be connected in daisy-chain configuration?

Yes, the PCA9704PWJ supports daisy-chaining via SDOUT-to-SDIN connections. All devices share common CS and SCLK lines, while their open-drain INT outputs can be tied together. This allows monitoring of 16+, 24+, or more switch inputs using a single SPI bus-ideal for large-scale automotive switch matrices.

Is the PCA9704PWJ AEC-Q100 qualified?

The PCA9704PWJ itself is not AEC-Q100 qualified; however, the pin-compatible PCA9704PW/Q900 variant is AEC-Q100 Grade 1 qualified (−40 °C to +125 °C) and available with PPAP documentation. For production automotive applications requiring formal qualification, PCA9704PW/Q900J is the recommended orderable part.