NXP Semiconductors MC33972ATEWR2

Overview

MC33972ATEWR2 from NXP Semiconductors is a 22-input automotive-grade switch detection interface IC with suppressed wake-up, SPI communication, and integrated 22:1 analog multiplexer. It operates from 5.5–26 V VPWR, supports 3.3/5.0 V SPI, delivers 2.0 mA or 16 mA selectable wetting current, and achieves 100 µA typical sleep-state VPWR supply current. It is used in vehicle body control modules to monitor door, seat, and lighting switches while minimizing battery drain.

For engineers reviewing the MC33972ATEWR2 datasheet, MC33972ATEWR2 pinout, MC33972ATEWR2 application, or MC33972ATEWR2 equivalent, key selection criteria include its dual-mode operation (Normal/Sleep), programmable SP/SG input configuration, open-drain INT/WAKE outputs, AMUX analog read capability, and AEC-Q100 qualification for automotive environments.

Technical Context

The MC33972ATEWR2 implements a dedicated switch monitoring architecture with two independent input groups: eight programmable SP inputs (switch-to-battery or switch-to-ground) and fourteen fixed SG inputs (switch-to-ground only), all referenced to a 4.0 V internal comparator. Its SPI interface operates up to 6.0 MHz with 24-bit command/response framing and supports daisy-chained or parallel multi-device configurations.

Sleep mode employs a calibrated scan timer (100–300 µs per channel) and suppresses wake-up events unless explicitly enabled per input via the Wake-up/Interrupt register. Internal wetting current generation (12–18 mA pulse, 1.8–2.2 mA sustain) is digitally configurable per channel group, and thermal shutdown activates at 155–185 °C for 16 mA sources only.

Key Specifications

Pinout & Package

MC33972ATEWR2 is housed in a 32-pin SOICW (wide-body) package with exposed pad (EW suffix), optimized for thermal dissipation and automotive board-level reliability. Pin 1 is GND; pins 5–8 and 25–28 are SP0–SP7; pins 9–15 and 18–24 are SG0–SG13; pin 16 is VPWR; pin 17 is WAKE; pin 29 is INT; pin 30 is AMUX; pin 31 is VDD; pin 32 is SO; pins 2–4 are SI, SCLK, CS.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar switch detection interface applications.

Compared with MC33972ATEWR2, MC33971ATEWR2 provides identical functionality at reduced channel count, while TPS65381AQDAGQ1 trades input count and analog capability for integrated power management and functional safety features-making each suitable for distinct architectural priorities.

Availability

MC33972ATEWR2 is available at Aetrix Electronics and suitable for automotive body control modules, seat electronics, lighting control systems, and industrial HMI panels requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MC33972ATEWR2 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 automotive, industrial, and IoT applications, with deep expertise in automotive electronics and AEC-Q100-qualified product development.

The MC33972ATEWR2 belongs to NXP's automotive system basis chip (SBC) and interface portfolio, designed specifically to replace discrete switch interface solutions in body electronics with robust, low-power, SPI-configurable ICs.

FAQ

What is the maximum VPWR voltage rating for the MC33972ATEWR2?

The MC33972ATEWR2 has an absolute maximum VPWR rating of 50 V, with a functional operating range of 5.5 V to 26 V. Transient voltages up to 40 V are supported for the switch inputs, but sustained operation above 26 V is outside specification and may affect parametric performance or reliability. External clamping is required for transients exceeding 40 V.

Does the MC33972ATEWR2 support both switch-to-battery and switch-to-ground configurations?

Yes, the MC33972ATEWR2 supports both configurations: eight SP inputs (SP0–SP7) are fully programmable as either switch-to-battery or switch-to-ground via the Settings Command register, while fourteen SG inputs (SG0–SG13) are fixed switch-to-ground only. Each group uses a 4.0 V internal reference for state detection.

How does the MC33972ATEWR2 achieve ultra-low sleep current?

The MC33972ATEWR2 achieves typical 100 µA VPWR sleep current through hardware-enforced low-power modes: internal clock gating, disabled analog blocks, calibrated 100–300 µs scan intervals, and suppression of wake-up events unless individually enabled. VDD removal further reduces logic supply current to 20 µA, though it disables SPI and wake-up via CS/INT.

Can the MC33972ATEWR2 read analog voltages from switch inputs?

Yes, the MC33972ATEWR2 includes a 22:1 analog multiplexer (AMUX) that routes any SP or SG input to the AMUX output pin (Pin 30). The buffered output supports ±2.0 µA offset current and ±10 mV offset voltage, enabling MCU ADC-based diagnostics such as contact resistance measurement or sensor bias validation.

Is the MC33972ATEWR2 pin-compatible with other devices in the 3397x family?

Yes, the MC33972ATEWR2 shares identical 32-pin SOICW (EW) packaging and pinout with MC33971ATEWR2 and MC33972TEWR2, enabling drop-in replacement where functional requirements align. Differences lie in input count (20 vs. 22), device revision (A vs. non-A), and switch input voltage range (40 V vs. 38 V), not physical layout.