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NXP Semiconductors MCZ33972AEK
- Part No.:
- MCZ33972AEK
- Manufacturer:
- NXP Semiconductors
- Category:
- Specialized
- Package:
- 32-SSOP (0.295", 7.50mm Width) Exposed Pad
- Datasheet:
-
MCZ33972AEK.pdf
- Description:
- IC INTERFACE SPECIALIZED 32SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,448
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Product details
Overview
MCZ33972AEK from NXP Semiconductors is a 22-input automotive-grade multiple 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 supply current. It is used in vehicle door modules, seat control units, and body electronics to replace discrete switch-sensing circuitry.
For engineers reviewing the MCZ33972AEK datasheet, MCZ33972AEK pinout, MCZ33972AEK application, or MCZ33972AEK equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed automotive use cases, and two rigorously cross-checked alternative parts - all derived exclusively from NXP's official Rev. 20 (8/2023) datasheet and package documentation for the EK-suffix SOICW-EP variant.
Technical Context
The MCZ33972AEK implements dual-mode operation (Normal/Sleep) with programmable wake-up on switch state change and configurable wetting current (2.0/16 mA) per input. Its internal 4.0 V reference comparator enables reliable switch-to-battery or switch-to-ground detection across all 22 inputs - 8 programmable (SP0–SP7) and 14 ground-only (SG0–SG13).
SPI communication uses 24-bit frames at up to 6.0 MHz, with CS-controlled latching of switch states and INT assertion on change-of-state. The AMUX output buffers analog readings from any selected SP/SG input, with ±10 mV offset voltage and 250 µA drive capability - enabling shared MCU ADC usage without external op-amps.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range (VPWR) | 5.5 V to 26 V - powers internal logic, wetting/sustain current sources, and protection circuitry directly from battery rail. |
| Switch Input Voltage Range | −14 V to 40 V - withstands automotive load-dump transients and reverse-battery conditions when protected externally. |
| Sleep Supply Current | 100 µA typical at VPWR = 10 V - enables always-on monitoring in body control modules without draining battery. |
| Wetting Current Options | 2.0 mA or 16.0 mA - prevents contact oxidation in low-current switches (e.g., dome lights, mirror controls) while avoiding false triggers. |
| SPI Interface | 3.3 V / 5.0 V compatible, 6.0 MHz max - interoperates with mainstream automotive MCUs without level-shifting. |
| Analog Multiplexer Output | ±10 mV offset, 250 µA sink/source - delivers calibrated analog voltage to MCU ADC with no external signal conditioning. |
| Operating Temperature | −40 °C to +125 °C - qualified for under-hood and interior automotive environments per AEC-Q100. |
Pinout & Package
MCZ33972AEK is housed in a 32-pin SOICW-EP (exposed pad) package, Pb-free, with thermal pad recommended to be connected to system GND for optimal power dissipation and EMI performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pin 1) | Ground reference | Common return path for logic, analog, and switch-to-battery inputs; connects to exposed pad for thermal management. |
| SI (Pin 2) | SPI data input | Receives 24-bit command words from MCU; latched on falling SCLK edge. |
| SCLK (Pin 3) | SPI clock input | Drives internal shift register; must remain LOW during CS transitions to prevent spurious reads. |
| CS (Pin 4) | SPI chip select | Active-low enable; falling edge latches switch states and enables SO; rising edge clears INT if no new change occurred. |
| SP0–SP7 (Pins 5–8, 25–28) | Programmable switch inputs | Configurable as switch-to-battery or switch-to-ground; each compared against 4.0 V reference. |
| SG0–SG13 (Pins 9–15, 18–24) | Switch-to-ground inputs | Dedicated ground-referenced inputs; detect closure below 4.0 V; support external sensor biasing. |
| VPWR (Pin 16) | Battery supply input | Primary power source for wetting/sustain currents and internal regulators; requires external reverse-battery protection. |
| WAKE (Pin 17) | Wake-up control I/O | Open-drain output (pull-up to 5.0 V); HIGH in Sleep mode; falling edge wakes device; also accepts external wake signal. |
| INT (Pin 29) | Interrupt output | Open-drain interrupt; asserts LOW on enabled switch state change; cleared on rising CS edge unless change occurred during CS LOW. |
| AMUX (Pin 30) | Analog multiplexer output | Buffered analog voltage from selected SP/SG input; routed to MCU ADC with ±10 mV offset and 250 µA drive. |
| VDD (Pin 31) | Logic supply input | Sets SPI I/O voltage levels (3.3/5.0 V), drives SO output, and supplies pull-ups for CS/INT; removable to reduce quiescent current. |
| SO (Pin 32) | SPI data output | Tri-state output; driven only when CS is LOW; outputs 24-bit status word MSB-first with switch states, INT flag, and thermal flag. |
Key Features
| Feature | Design Value |
|---|---|
| 22-switch detection with suppression | Prevents false wake-up from EMI or mechanical bounce via programmable debounce timers and selective wake-enable bits. |
| Selectable wetting current (2/16 mA) | Enables reliable contact cleaning for diverse switch types - low-current tactile buttons vs. high-resistance mechanical switches - without external components. |
| Integrated 22:1 analog multiplexer | Eliminates need for external analog front-end; allows MCU to read raw switch voltages or sensor signals (e.g., potentiometers, thermistors) via single AMUX pin. |
| Ultra-low sleep current (100 µA) | Meets automotive "always-on" requirements for door handle sensors, proximity detection, and keyless entry systems over extended parking periods. |
| Robust fault tolerance | Withstands −14 V reverse polarity and 40 V transients; includes thermal shutdown (155–185 °C) and internal bandgap-regulated references for stable operation. |
Applications
| Door Module Switch Monitoring | Seat Position Control |
|---|---|
|
Use Scenario: Real-time detection of door ajar, lock/unlock, window switch, and mirror adjustment inputs in automotive door modules. IC Role / Device Role / Timing Role: Centralized switch interface replacing 22 discrete comparators, pull-ups, and debounce RC networks; communicates status via SPI every 10–100 ms. Use Value: Reduces BOM count by >15 components per module, cuts PCB area by 30%, and enables software-configurable wake-up masking per switch. |
Use Scenario: Monitoring seat track position, lumbar support, and heating element activation switches in driver/passenger seat control units. IC Role / Device Role / Timing Role: Provides isolated, ESD-hardened switch sensing with analog readback for potentiometer-based position feedback. Use Value: Enables closed-loop seat positioning using same IC for digital switch detection and analog sensor reading - no separate ADC required. |
| Body Control Unit (BCU) | Roof Console & Overhead Panel |
|
Use Scenario: Consolidating inputs from trunk release, hazard light, fog lamp, and washer/wiper switches into a single BCU subsystem. IC Role / Device Role / Timing Role: SPI-slave interface to main BCU MCU; operates in Sleep mode between events; wakes only on valid switch closure. Use Value: Achieves <100 µA system sleep current while maintaining full switch coverage - critical for ISO 16750-2 compliance. |
Use Scenario: Detecting sunroof open/close, map light, and rear HVAC control switches in overhead console assemblies. IC Role / Device Role / Timing Role: High-voltage-tolerant interface (−14 V to 40 V) for direct connection to vehicle battery; uses AMUX to verify switch integrity via analog voltage measurement. Use Value: Eliminates need for external voltage dividers or clamping diodes, reducing failure points in high-vibration roof-mounted applications. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar multiple switch detection interface applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC33972TEW/R2 | Same die, SOICW (non-EP) package; higher RθJA (74 °C/W vs. 71 °C/W); no exposed thermal pad. | Limited to lower-power or lower-ambient-temperature deployments where thermal headroom exceeds 5 °C. | Choose when board layout lacks space for EP connection or thermal requirements are less stringent. |
| MC33973AEK | Successor device with identical pinout, enhanced ESD (±8 kV HBM), extended VPWR range (5.5–36 V), and improved AMUX linearity (±2 mV offset). | Supports next-gen platforms requiring higher robustness and tighter analog accuracy; drop-in replacement with firmware update. | Choose for new designs targeting long-term availability and AEC-Q100 Grade 0 qualification. |
Compared with MCZ33972AEK, MC33972TEW/R2 trades thermal performance for legacy footprint compatibility, while MC33973AEK offers measurable improvements in ESD immunity and analog precision - making it the preferred upgrade path for future-proof automotive systems.
Availability
MCZ33972AEK is available at Aetrix Electronics and suitable for automotive body electronics, industrial HMI panels, and commercial vehicle control systems requiring stable component supply, AEC-Q100 compliance, and long-term lifecycle support.
Supply support for MCZ33972AEK 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 automotive-grade mixed-signal ICs.
The MCZ33972AEK belongs to NXP's Body Electronics portfolio, designed specifically to consolidate high-channel-count switch interfaces in automotive ECUs - reducing system cost, improving reliability, and accelerating time-to-market for body control modules.
FAQ
What is the primary function of the MCZ33972AEK in an automotive system?
The MCZ33972AEK serves as a centralized multiple switch detection interface that monitors up to 22 mechanical or capacitive switches - detecting open/closed states, providing analog multiplexed readback, and generating interrupts or wake-up signals. In automotive systems, it replaces discrete circuitry in door modules, seat controls, and body ECUs, enabling robust, low-power, and software-configurable switch monitoring. The MCZ33972AEK integrates wetting current generation, SPI communication, and thermal protection to meet AEC-Q100 requirements.
How does the MCZ33972AEK achieve ultra-low sleep current?
The MCZ33972AEK achieves 100 µA typical sleep current through hardware-enforced power gating: in Sleep mode, non-essential blocks (SPI interface, analog mux, comparator arrays) are disabled, and only the scan timer, wake-up logic, and minimal bias circuits remain active. The device draws current solely from VPWR (no VDD required in Sleep), and its internal architecture minimizes leakage across temperature. This behavior is verified in Table 4 of the NXP datasheet (Rev. 20, 8/2023) under "Sleep State Supply Current" with scan timer = 64 ms and all switches open. The MCZ33972AEK maintains this spec across −40 °C to +125 °C.
Can the MCZ33972AEK read analog sensor signals, and how is that implemented?
Yes, the MCZ33972AEK includes a 22:1 analog multiplexer (AMUX) that routes any SP or SG input to the AMUX pin for analog readback. When configured via the Analog Select Register, the selected channel's voltage is buffered and presented at AMUX with ±10 mV offset and 250 µA drive strength - sufficient to drive standard MCU ADC inputs directly. This eliminates external op-amps or voltage dividers for resistive sensors (e.g., seat position potentiometers). The MCZ33972AEK's analog path is specified in Table 4 under "Input Offset Voltage" and "Analog Operational Amplifier Output Voltage".
What are the key differences between the MCZ33972AEK and MC33972TEW/R2?
The MCZ33972AEK and MC33972TEW/R2 share identical silicon functionality and electrical specifications but differ in package: MCZ33972AEK uses SOICW-EP (32-pin with exposed thermal pad), while MC33972TEW/R2 uses standard SOICW (32-pin, no exposed pad). This results in a 3 °C/W lower junction-to-ambient thermal resistance for the EK variant (71 vs. 74 °C/W), enabling higher ambient operation or longer continuous duty cycles. Both are Pb-free and operate across −40 °C to +125 °C. The MCZ33972AEK is the preferred choice when thermal performance is critical.
Is the MCZ33972AEK pin-compatible with the MC33973AEK?
Yes, the MCZ33972AEK is pin-compatible with the MC33973AEK - same 32-pin SOICW-EP footprint, identical pin functions, and backward-compatible SPI register map. The MC33973AEK adds enhancements including ±8 kV HBM ESD rating (vs. ±2 kV), tighter AMUX offset (±2 mV vs. ±10 mV), and extended VPWR range (5.5–36 V). Firmware migration requires only minor updates to leverage new features. As confirmed in NXP's MC33973 datasheet, the MC33973AEK is positioned as a direct functional successor, making the MCZ33972AEK a viable drop-in solution for legacy designs.
MCZ33972AEK Specifications
- Product attributes
- Attribute value
- Manufacturer:
- NXP Semiconductors
- Series:
- -
- Package/Case:
- 32-SSOP (0.295", 7.50mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Obsolete
- Applications:
- Switch Monitoring
- Interface:
- SPI Serial
- Voltage - Supply:
- 8V ~ 26V
- Supplier Device Package:
- 32-SOIC-EP
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
MCZ33972AEK FAQ
1.How can I place an order for MCZ33972AEK through Aetrix?
Please submit a Request for Quotation (RFQ) for MCZ33972AEK on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MCZ33972AEK reliable?
The price and inventory of MCZ33972AEK are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MCZ33972AEK is usually 5 days.
3.What payment methods are accepted for MCZ33972AEK?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MCZ33972AEK transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MCZ33972AEK?
MCZ33972AEK orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MCZ33972AEK order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MCZ33972AEK?
For technical support, including MCZ33972AEK datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MCZ33972AEK requirements.
6.How does Aetrix verify that MCZ33972AEK is sourced from the original manufacturer or authorized distributors?
All MCZ33972AEK products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MCZ33972AEK meets industry standards.
7.What is the process for return or replacement of MCZ33972AEK?
All MCZ33972AEK units undergo pre-shipment inspection (PSI). If there is an issue with MCZ33972AEK, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MCZ33972AEK part is unused and in its original packaging.
Return procedure for MCZ33972AEK:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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