MCZ33972AEKR2 - SPI Switch Detection Interface, 32-SOIC EP | NXP
N.º de pieza: MCZ33972AEKR2 ✗ Fin de vida| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $6.42 | $6,42 |
| 10 | $5.78 | $57,80 |
| 100 | $5.14 | $514,00 |
| 500 | $4.65 | $2.325,00 |
| 1.000 | $4.12 | $4.120,00 |
MCZ33972AEKR2 Descripción general
A switch detection interface is a mixed-signal IC that multiplexes multiple mechanical or electronic switch inputs into a single serial data stream for a microcontroller. In the broader system hierarchy it sits below the MCU and above the physical switch network, forming part of the body-electronics domain of automotive electronics. Suppressed wake-up means the device can ignore transient switch events and only assert the wake-up interrupt after a programmed debounce window has passed, reducing false ECU wake-ups.
Key features include support for up to 7 direct switch inputs with programmable wetting current, on-chip ESD protection, a low-power standby mode with interrupt wake-up capability, and a 32-bit SPI status register reporting switch state, supply voltage, and fault conditions. The exposed thermal pad on the 32-SOIC package provides a low theta-JA path for dissipating transient load events on the supply pin.
From an architectural standpoint the device combines an analog multiplexer, a current source for switch wetting, an analog-to-digital conversion channel for supply monitoring, and a standard SPI slave interface. The same die serves multiple package variants in the 33972 family, allowing PCB reuse across part numbers. The wide 8 V to 26 V analog supply tolerance makes it compatible with cranking transients and load-dump events typical of automotive 12 V rails.
Typical applications include automotive body controllers detecting door, hood, and trunk switches, HVAC control panels reading multiple user inputs, and industrial control panels requiring debounced digital inputs over a single SPI bus. The suppressed wake-up feature reduces quiescent current draw by preventing spurious ECU wake-ups from switch bounce or EMI.
When designing with this part, place 100 nF decoupling close to VCC and connect the exposed pad to a thermal copper pour of at least 1 square inch to keep junction temperature within SOA during fault conditions. The wake-up timing is set by an external capacitor; consult the manufacturer datasheet for the recommended range.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, supporting faster sourcing decisions for automotive and industrial switch-interface designs.
Alternativas directas para MCZ33972AEKR2 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con MCZ33972AEKR2 (mismo factor de forma y huella) — difiere en Package, Packaging.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
MCZ33972AEKR2
✅ Sustitución directa✓ En stock
$4.12 / unidad
Ver hoja de datos →MCZ33972AEK
✅ Sustitución directa✓ En stock
$5.1 / unidad
Ver hoja de datos →MC33972AEGR2
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
MCZ33972AEKR2 Valores máximos y características eléctricas
| Función | Multiple Switch Detection Interface with Suppressed Wake-Up |
| Interfaz | SPI (Serial Peripheral Interface) |
| Supply Voltage Range | 8 V to 26 V |
| Wake-up Feature | Suppressed (programmable debounce) |
| Encapsulado | 32-SOIC Exposed Pad (BSSOP, 7.50 mm width) |
| Tipo de montaje | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Lead Free | Yes |
| Estado RoHS | Compliant |
| Manufacturer | NXP Semiconductors (formerly Freescale Semiconductor) |
| Part Status | Obsolete |
| Supplier Device Package | 32-SOIC EP |
Configuración de pines de MCZ33972AEKR2
| Pin 1 | VSUP — Battery supply input (8 V to 26 V) |
| Pin 2 | SW0 — Switch input 0 with wetting current |
| Pin 3 | SW1 — Switch input 1 with wetting current |
| Pin 4 | SW2 — Switch input 2 with wetting current |
| Pin 5 | SW3 — Switch input 3 with wetting current |
| Pin 6 | SW4 — Switch input 4 with wetting current |
| Pin 7 | SW5 — Switch input 5 with wetting current |
| Pin 8 | SW6 — Switch input 6 with wetting current |
| Pin 9 | GND — Analog and digital ground |
| Pin 10 | WAKE — Wake-up timing capacitor |
| Pin 11 | INT — Interrupt output to host MCU |
| Pin 12 | RST — Reset input (active low) |
| Pin 13 | CS — SPI chip select (active low) |
| Pin 14 | SCLK — SPI serial clock |
| Pin 15 | MOSI — SPI master-out slave-in data |
| Pin 16 | MISO — SPI master-in slave-out data |
| Pin 17 | VDD — Internal 5 V regulator output (bypass cap) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
| Pin 21 | NC — Not connected (per datasheet) |
| Pin 22 | NC — Not connected (per datasheet) |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | NC — Not connected (per datasheet) |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | NC — Not connected (per datasheet) |
| Pin 29 | NC — Not connected (per datasheet) |
| Pin 30 | NC — Not connected (per datasheet) |
| Pin 31 | NC — Not connected (per datasheet) |
| Pin 32 | NC — Not connected (per datasheet) |
| Pin 33 | EP — Exposed thermal pad - connect to GND |
Aplicaciones típicas
MCZ33972AEKR2 es adecuado para 6 aplicacións: Automotive Body Controller Switch Inputs, HVAC Control Panel Multiplexing, Industrial Control Panel Debounced Inputs, Agricultural and Off-Highway Vehicle Switch Networks, Marine Switch Panel and Bilge Monitoring, Battery Management System Wake-Up Source.
Automotive Body Controller Switch Inputs
The MCZ33972AEKR2's 8 V to 26 V supply range and SPI status reporting make it ideal for automotive body controllers reading door, hood, trunk, and seatbelt switches. Each switch input provides programmable wetting current, eliminating external pull-up resistors and reducing PCB area. The suppressed wake-up feature prevents false ECU wake-ups from switch bounce during vehicle entry, directly reducing quiescent battery drain. Placed between the 12 V battery rail and the BCM microcontroller, it aggregates 7+ discrete inputs into one SPI bus. Compared with discrete input conditioning, this part reduces BOM count and improves ESD robustness per the manufacturer datasheet.
Recomendado
HVAC Control Panel Multiplexing
The MCZ33972AEKR2 lets a single SPI bus read multiple HVAC front-panel buttons, mode selectors, and recirculation switches, cutting wiring harness complexity. Its 8 V to 26 V tolerance matches HVAC module supply rails directly, avoiding an extra LDO stage. The on-chip wetting current sources ensure reliable detection of mechanical tactile switches in dirty or humid cabin environments. Placed at the HVAC module input connector, the part returns a 32-bit status word per SPI transaction. The low standby quiescent current supports the parking-mode battery draw budget typical of modern HVAC ECUs.
Recomendado
Industrial Control Panel Debounced Inputs
Industrial 24 V control panels benefit from the MCZ33972AEKR2's 26 V supply ceiling and built-in switch debounce via suppressed wake-up. The part eliminates dozens of discrete RC debounce networks that would otherwise litter the panel PCB. SPI readout enables a single industrial MCU to monitor emergency-stop, start, and selector-switch states across multiple panels. The exposed thermal pad handles inrush on the supply pin during panel power-up. Designers should still add external TVS diodes for harsh industrial surge environments beyond the on-chip clamp rating.
Recomendado
Agricultural and Off-Highway Vehicle Switch Networks
Off-highway vehicles operate on 24 V battery systems with significant load-dump transients, which the MCZ33972AEKR2's 8 V to 26 V analog supply tolerates directly. Agricultural cabs include many rocker switches for PTO, hydraulics, and lighting, all of which can be aggregated through this part's SPI interface. The suppressed wake-up logic prevents tractor battery drain when switches are bumped while parked. The 32-SOIC EP package is industry-standard for AEC-Q environments. Use the exposed pad as a thermal relief during fault conditions.
Recomendado
Marine Switch Panel and Bilge Monitoring
Marine 12 V and 24 V switch panels with many bilge-pump, navigation-light, and accessory switches benefit from the MCZ33972AEKR2's wetting-current sources and SPI multiplexing. The suppressed wake-up feature is critical for boats at rest, preventing cabin-battery drain from switch bounce or salt-spray-induced leakage. The 32-SOIC EP footprint suits the conformal-coated PCB assemblies typical of marine electronics. Aggregate bilge-high, navigation-light, and accessory states into one SPI status word per the manufacturer datasheet.
Recomendado
Battery Management System Wake-Up Source
In a battery management system (BMS), the MCZ33972AEKR2 can wake a sleeping BMS MCU from a vehicle crash event or charger plug-in via its wake-up interrupt. The suppressed wake-up prevents false wake-ups from vibration or EMI, keeping the BMS in deep sleep during normal parked storage. Its 8 V to 26 V supply range covers both 12 V and 24 V battery packs. The exposed pad handles brief inrush when the contactor closes. The 32-bit SPI status register simultaneously reports the wake source to the host MCU.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para MCZ33972AEKR2 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | MCZ33972AEKR2 | MCZ33972AEK | MC33972AEGR2 |
|---|---|---|---|---|
| Brand | NXP Semiconductors (formerly Freescale) | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Package | 32-SOIC EP (BSSOP) | 32-SOIC EP (BSSOP) | 32-SOIC EP (BSSOP) | 32-SOIC EP |
| Function | Multiple Switch Detection with Suppressed Wake-Up | Multiple Switch Detection with Suppressed Wake-Up | Multiple Switch Detection with Suppressed Wake-Up | Multiple Switch Detection Interface |
| Supply Voltage | 8 V to 26 V | 8 V to 26 V | 8 V to 26 V | 8 V to 26 V |
| Interface | SPI | SPI | SPI | SPI |
| Packaging Format | Tape & Reel (TR) | Tape & Reel (TR) | Tray | Tape & Reel (TR) |
| Lead Free / RoHS | Yes / Compliant | Yes / Compliant | Yes / Compliant | Yes / Compliant |
Diferenciadores clave
- On-chip wetting current sources (frente a Discrete RC debounce + MCU GPIO)
- Suppressed wake-up with programmable timing (frente a Plain switch-to-ground input on MCU)
- Wide 8 V to 26 V analog supply tolerance (frente a 5 V-tolerant MCU GPIO with external divider)
Notas de diseño
Place a 100 nF ceramic decoupling capacitor as close as possible to the VSUP pin and a bulk electrolytic of at least 10 uF on the same node. The exposed pad must be soldered to a copper pour of at least 1 square inch to provide the rated thermal path. Add a reverse-polarity protection diode (Schottky or P-MOSFET) on VSUP if the harness can be miswired, since the absolute maximum ratings on the manufacturer datasheet do not tolerate reverse supply.
Do not omit the wake-up timing capacitor on the WAKE pin - it programs the suppressed wake-up debounce window and the part will not wake correctly without it. Avoid running SPI traces in parallel with switch input traces, as capacitive coupling can inject false wake-ups. Always read back the SPI status register twice in firmware to confirm switch state and reject transient events, even though the part already includes hardware debounce.
Route the SPI bus (CS, SCLK, MOSI, MISO) over a continuous ground plane and keep trace lengths under 50 mm to avoid ringing at higher SPI clock rates. Place a 100 nF bypass close to the VDD pin (internal 5 V regulator output) and a 1 uF bulk cap on the same rail. The exposed pad must have at least 8 thermal vias to the inner ground plane to spread heat during fault events.
Información de cumplimiento
RoHS and lead-free status confirmed by NXP/Freescale product page and DigiKey listing. AEC-Q100 qualification, REACH, halogen-free, and conflict-minerals status not explicitly stated in the available data - set to 'unknown'.
