NXP Semiconductors MC33972TEWR2

Overview

MC33972TEWR2 from NXP Semiconductors (formerly Freescale) 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 supply current. It serves as the primary switch monitoring front-end in vehicle body control modules.

For engineers reviewing the MC33972TEWR2 datasheet, MC33972TEWR2 pinout, MC33972TEWR2 application, or MC33972TEWR2 equivalent, key selection criteria include its 8 programmable SP inputs (switch-to-battery/ground), 14 dedicated SG-to-ground inputs, open-drain INT/WAKE outputs, AMUX analog readback capability, and guaranteed -40 °C to 125 °C operation in SOICW package.

Technical Context

The MC33972TEWR2 implements dual-mode operation (Normal/Sleep) with hardware-controlled wake-up suppression via WAKE and INT open-drain outputs. Its internal architecture integrates a 22-channel analog multiplexer, bandgap-referenced 4.0 V comparators for all inputs, programmable wetting current sources/sinks (16 mA pulse / 2.0 mA sustain), and SPI-configurable registers for input polarity, wake-up enable, timer calibration, and analog channel selection.

It uses VPWR (8–26 V) for switch biasing and internal logic power, while VDD (3.1–5.25 V) sets SPI I/O voltage levels and drives SO output and CS/INT pull-ups. Switch state changes trigger interrupt latching on CS falling edge, and analog readings are routed through AMUX with ±2.5 mV offset and 250 μA sourcing/sinking capability.

Key Specifications

Pinout & Package

MC33972TEWR2 is housed in a 32-pin SOICW (Wide-body Small Outline Integrated Circuit) package with exposed pad (EW suffix), RoHS-compliant and Pb-free. The exposed pad is recommended to be connected to GND for thermal and EMI performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC33972TEWR2, MC33973TEWR2 adds CAN but increases sleep current and cost, while TPIC2101QPWPRQ1 reduces channel count and removes analog/wetting features - making MC33972TEWR2 the optimal balance of integration, diagnostics, and ultra-low-power performance for 22-switch automotive body control.

Availability

MC33972TEWR2 is available at Aetrix Electronics and suitable for automotive body control modules, door modules, seat control units, and HVAC interface designs requiring stable component supply, long-term lifecycle support, and AEC-Q100 compliance.

Supply support for MC33972TEWR2 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 high-reliability analog and mixed-signal solutions.

The MC33972TEWR2 belongs to NXP's automotive system basis chip (SBC) and interface portfolio, designed specifically for robust, low-power switch monitoring in vehicle body electronics with stringent EMC and thermal requirements.

FAQ

What is the maximum switch input voltage the MC33972TEWR2 can tolerate?

The MC33972TEWR2 supports a switch input voltage range of −14 V to 40 V DC. This rating applies to all SP and SG inputs and ensures survivability during automotive load dump (ISO 7637-2 Pulse 5a) and reverse-battery conditions when used with appropriate external protection. Exceeding 40 V may cause permanent damage.

Does the MC33972TEWR2 require external pull-up or pull-down resistors on its switch inputs?

No, the MC33972TEWR2 does not require external pull resistors. It provides internally programmable wetting and sustain currents (2.0 mA or 16 mA) for all 22 inputs, eliminating the need for discrete components. Pull-up/pull-down functionality is fully integrated and configurable via SPI registers.

Can the MC33972TEWR2 read analog voltages from external sensors?

Yes, the MC33972TEWR2 includes a 22:1 analog multiplexer (AMUX) that routes any selected SP or SG input to the AMUX pin. The buffered output supports ±2.5 mV offset and can source/sink 250 μA, enabling direct connection to an MCU's ADC for diagnostic voltage measurements or sensor interfacing.

How does wake-up suppression work in the MC33972TEWR2?

Wake-up suppression in the MC33972TEWR2 prevents false triggers by requiring both a valid switch state change *and* confirmation via internal timing validation before asserting WAKE or INT. This avoids spurious wake events caused by ESD, noise, or contact bounce - critical for meeting automotive quiescent current targets.

Is the MC33972TEWR2 pin-compatible with other devices in the 3397x family?

Yes, the MC33972TEWR2 is pin-compatible with MC33973TEWR2 and MC33974TEWR2 in the same SOICW-32 package. Register maps differ slightly (e.g., MC33973 adds CAN control bits), but hardware layout and power/signal connections remain identical - enabling drop-in replacement for functional upgrades.