NXP Semiconductors PCA9701HF,118

Overview

PCA9701HF,118 from NXP Semiconductors is a 16-channel, 18 V tolerant SPI General Purpose Input (GPI) shift register for automotive switch monitoring. It features open-drain interrupt output, 2.5–5.5 V supply range, <2.5 µA quiescent current, and operates from −40 °C to +125 °C. Used in body control modules to detect switch state changes under harsh battery conditions including 40 V load dump.

For engineers reviewing the PCA9701HF,118 datasheet, PCA9701HF,118 pinout, PCA9701HF,118 application, or PCA9701HF,118 equivalent, key selection criteria include 18 V input tolerance with 100 kΩ series resistor, SPI interface timing up to 5 MHz, interrupt masking capability via INT_EN, and HWQFN24 thermal performance for high-density automotive PCBs.

Technical Context

The PCA9701HF,118 implements a 16-bit parallel-input/serial-output shift register synchronized to SPI clock edges: falling edge of CS captures input status into the input status register and clears interrupt; rising edge of SCLK loads the shift register; SDIN is sampled on SCLK falling edge. All 16 GPI inputs feature 18 V breakdown ESD protection and 0.4 × VDD LOW threshold (min. 2.0 V at 4.5 V).

Its interrupt logic asserts active-LOW on any input state change and supports wired-AND daisy-chaining across multiple devices. The device uses internal 20 µA pull-down on SDIN and requires external 10 kΩ pull-up on INT. Input leakage remains ≤±1 µA at 17 V with 100 kΩ series resistor, enabling robust operation in double-battery and reverse-battery scenarios.

Key Specifications

Pinout & Package

PCA9701HF,118 is housed in a 4 × 4 × 0.75 mm HWQFN24 package (SOT994-1) with exposed thermal pad requiring soldering to PCB for thermal and electrical integrity. VSS connects to both pin 9 and the center pad; proper grounding of both is mandatory for operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar GPI monitoring applications.

Compared with PCA9701PW,118, PCA9701HF,118 offers lower thermal resistance and smaller footprint; compared with PCA9703HF,118, it lacks per-input interrupt masking but provides identical 16-bit monitoring and 18 V tolerance at lower gate count and cost.

Availability

PCA9701HF,118 is available at Aetrix Electronics and suitable for automotive body control modules, industrial emergency lighting systems, and System Basis Chip (SBC) wake extension applications requiring stable component supply across extended temperature and high-reliability environments.

Supply support for PCA9701HF,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 specializing in secure connectivity solutions for automotive, industrial, and IoT markets, with deep expertise in automotive-grade mixed-signal ICs.

The PCA9701HF,118 belongs to NXP's automotive GPI portfolio designed specifically for robust switch monitoring in harsh electrical environments-including load dump, reverse battery, and jump-start conditions-within body electronics and power management subsystems.

FAQ

What is the maximum input voltage the PCA9701HF,118 can tolerate on its IN0–IN15 pins?

The PCA9701HF,118 GPI inputs tolerate up to 18 V when used with a minimum 100 kΩ series resistor. This rating supports automotive transients including 40 V load dump (with current limiting), 27 V jump start, and reverse-battery conditions. Without the series resistor, absolute maximum input voltage is 6.0 V per Table 5.

Does the PCA9701HF,118 require external pull-up resistors on its interrupt output?

Yes, the PCA9701HF,118 features an open-drain INT pin requiring an external pull-up resistor-typically 10 kΩ-to the host controller's logic supply. This configuration enables wired-AND connection of multiple PCA9701HF,118 devices to a shared interrupt line without external logic.

How does the PCA9701HF,118 handle switch debouncing in automotive applications?

The PCA9701HF,118 does not include hardware debouncing; it reports raw input state changes. Debouncing must be implemented in firmware via interrupt service routine (ISR) sampling or software timers. Its 5 MHz SPI interface allows rapid re-reading of input status to confirm stable transitions.

Can the PCA9701HF,118 be used with a 3.3 V microcontroller SPI interface?

Yes, the PCA9701HF,118 supports VDD from 2.5 V to 5.5 V, making it fully compatible with 3.3 V systems. Its SPI inputs (CS, SCLK, SDIN) meet 0.7 × VDD VIH and 0.3 × VDD VIL thresholds, ensuring reliable communication with standard 3.3 V logic levels.

What is the function of the INT_EN pin on the PCA9701HF,118?

The INT_EN pin on the PCA9701HF,118 controls interrupt output assertion: when HIGH, INT reflects input state changes; when LOW, INT is disabled and placed in high-impedance state. This allows dynamic suppression of interrupts during known noisy periods or firmware initialization sequences.