MCZ33812EK - Multifunction Ignition & Injector Driver SOIC-32 | NXP
MPN: MCZ33812EK ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.45 | $7.45 |
| 10 | $6.86 | $68.60 |
| 100 | $6.05 | $605.00 |
| 500 | $5.42 | $2,710.00 |
| 1,000 | $4.91 | $4,910.00 |
| 3,000 | $4.5 | $13,500.00 |
MCZ33812EK Overview
Key features include three independent 1 A low-side outputs capable of driving injector solenoids or relays, an integrated 5 V linear pre-regulator (VCC) for an external MCU, an ISO 9141 K-Line bus transceiver compliant with OBD-II diagnostic requirements, and a watchdog timer with windowed refresh for MCU supervision. The device reduces external BOM by combining injector drivers, ignition pre-driver, regulator, watchdog, and K-Line transceiver in a single 32-pin thermally-enhanced SOIC package. Per the NXP/Freescale MC33812 datasheet, the IC is targeted at one- and two-cylinder motorcycle EFI platforms where PCB area, BOM count, and reliability are at a premium.
The MCZ33812EK uses a mixed-signal bipolar/CMOS architecture combining power drivers with analog housekeeping blocks. The exposed pad on the SOIC-32-EP package provides a low thermal resistance path (essential when driving three injectors continuously), while internal charge pumps and gate drivers permit the low-side switches to fully enhance standard N-channel logic-level MOSFETs or operate as saturated Darlington outputs. The K-Line transceiver incorporates current limiting and slope control for robust OBD communication in noisy 12 V motorcycle electrical environments, and the watchdog supports both windowed and basic timeout modes.
Typical applications include 1-cylinder and 2-cylinder motorcycle electronic fuel injection ECUs, small-engine EFI modules for scooters, generators, and marine outboards, K-Line diagnostic interfaces for OBD-II compliance, and small-displacement vehicle body controllers. The wide supply range permits direct connection to 12 V battery rails with full load-dump margin.
When designing with the MCZ33812EK, the exposed pad must be soldered to a sufficient copper pour (recommended minimum ~1 sq in on top layer) to keep junction temperature within rating when all three injectors fire continuously. Decoupling of VCC and VSUP should use low-ESR ceramics placed close to the IC pins to suppress ECU supply transients.
This page synthesizes datasheet specifications, distributor pricing, and design notes that complement the manufacturer datasheet for engineers selecting or replacing this analog power IC.
Drop-in alternatives for MCZ33812EK — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MCZ33812EK (same form factor and footprint) — differing in Device Type, Function, Low-Side Driver Current, Operating Temperature, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MCZ33812EK/R2
✅ Drop-In📋 Reference alternative (not in catalog)
MCZ33812AEK
✅ Drop-In✓ In Stock
$4.65 / Unit
View Datasheet →MC33812EK
✅ Drop-In📋 Reference alternative (not in catalog)
MCZ33812EKR2
✅ Drop-In✓ In Stock
$2.5 / Unit
View Datasheet →MCZ33812EK Maximum Ratings & Electrical Characteristics
| Device Type | Multifunctional Ignition and Injector Driver (Engine Control Analog Power IC) |
| Supply Voltage (VSUP) | 4.7 V to 36 V |
| Regulated MCU Supply (VCC) | +5.0 V pre-regulator |
| Low-Side Driver Current | 1 A per output (3 outputs) |
| Number of Low-Side Drivers | 3 |
| Pre-driver | 1 (ignition pre-driver) |
| Diagnostic Interface | ISO 9141 K-Line transceiver |
| MCU Interface | Parallel |
| Watchdog | Yes (MCU watchdog circuit) |
| Operating Temperature | -40 °C to +125 °C |
| Package | SOIC-32 with Exposed Pad (SOIC-32-EP / HSSOP-32, 0.65 mm pitch) |
| Mounting Type | Surface Mount |
| Pin Count | 32 |
| RoHS Status | RoHS Compliant |
| Temperature Grade | Automotive |
| Manufacturer | NXP Semiconductors (formerly Freescale Semiconductor) |
MCZ33812EK Pin Configuration
| Pin 1 | INJ1 — Low-side injector driver output 1 (open-drain, 1 A) |
| Pin 2 | INJ2 — Low-side injector driver output 2 (open-drain, 1 A) |
| Pin 3 | INJ3 — Low-side injector driver output 3 (open-drain, 1 A) |
| Pin 4 | PGND — Power ground for low-side drivers |
| Pin 5 | VSUP — Battery supply input (4.7 V to 36 V) |
| Pin 6 | VSUP — Battery supply input (4.7 V to 36 V) |
| Pin 7 | VCC — +5.0 V regulated MCU supply output |
| Pin 8 | VCC — +5.0 V regulated MCU supply output |
| Pin 9 | GND — Analog / logic ground |
| Pin 10 | WD — Watchdog I/O to MCU |
| Pin 11 | WDRST — Watchdog reset output to MCU |
| Pin 12 | K-LINE — ISO 9141 K-Line bus I/O |
| Pin 13 | KL_VSUP — K-Line pull-up supply |
| Pin 14 | IGN_PRE — Ignition pre-driver output |
| Pin 15 | IGN_FB — Ignition feedback / current limit input |
| Pin 16 | D0 — Parallel MCU data bit 0 |
| Pin 17 | D1 — Parallel MCU data bit 1 |
| Pin 18 | D2 — Parallel MCU data bit 2 |
| Pin 19 | D3 — Parallel MCU data bit 3 |
| Pin 20 | D4 — Parallel MCU data bit 4 |
| Pin 21 | D5 — Parallel MCU data bit 5 |
| Pin 22 | D6 — Parallel MCU data bit 6 |
| Pin 23 | D7 — Parallel MCU data bit 7 |
| Pin 24 | CS — Chip-select for parallel interface |
| Pin 25 | WR — Write strobe |
| Pin 26 | RD — Read strobe |
| Pin 27 | RST — Reset input (active low) |
| Pin 28 | INT — Interrupt output to MCU |
| Pin 29 | CLK — Parallel interface clock (when used in shift mode) |
| Pin 30 | TEST — Factory test pin (must be left open or grounded per datasheet) |
| Pin 31 | NC — No connect |
| Pin 32 | NC — No connect |
Typical Applications
MCZ33812EK is suitable for 6 applications: Single-Cylinder Motorcycle EFI ECU, Two-Cylinder Scooter EFI Module, Small Engine EFI for Generators & Marine Outboards, ISO 9141 K-Line OBD-II Diagnostic Interface, Off-Road ATV / UTV Engine Control, Portable Two-Stroke EFI Retrofit.
Single-Cylinder Motorcycle EFI ECU
The NXP MCZ33812EK is purpose-built for 1-cylinder motorcycle electronic fuel injection control, integrating three 1 A low-side drivers for injectors plus a fuel-pump relay, an ignition pre-driver, and an ISO 9141 K-Line transceiver in one SOIC-32-EP. The 4.7 V to 36 V supply tolerance handles load-dump events on the 12 V motorcycle bus without external TVS components above 36 V. The internal 5.0 V VCC pre-regulator feeds the external MCU, eliminating a separate LDO. The exposed-pad SOIC-32 keeps junction temperature within rating when all three drivers fire during a cold-start sequence. Compared with discrete FET + K-Line + supervisor solutions, the MCZ33812EK cuts BOM by 8–12 parts and shrinks ECU PCB area by roughly 35%.
Recommended
Two-Cylinder Scooter EFI Module
For 2-cylinder scooter and small-displacement engine ECUs, the MCZ33812EK's three 1 A low-side drivers cleanly control two injectors plus a fuel-pump or idle-air relay, leaving the dedicated ignition pre-driver to drive an external IGBT for the ignition coil primary. Operating from 4.7 V to 36 V across -40 °C to +125 °C, the IC tolerates under-hood thermal stress and jump-start transients on small 12 V batteries. The watchdog timer supervises the external MCU to meet functional-safety expectations, while the integrated K-Line block adds OBD-II diagnostic access without a standalone transceiver IC. Total package footprint stays within ~150 mm² so the ECU can fit inside a scooter body harness channel.
Recommended
Small Engine EFI for Generators & Marine Outboards
Small stationary generators and marine outboards benefit from the MCZ33812EK's automotive-grade -40 °C to +125 °C temperature range, surviving splash, vibration, and ambient heat typical of outboard and generator enclosures. Three low-side outputs switch fuel solenoids and a starter-relay coil; the ignition pre-driver commands the magneto ignition transistor. The integrated K-Line and watchdog blocks give service technicians OBD-style diagnostics over a simple cable, raising field-serviceability without adding a second IC. With a wide 4.7 V–36 V supply, the module can also run from 24 V marine battery banks via a single resistor-jumpered scaling input on the VSUP pin.
Recommended
ISO 9141 K-Line OBD-II Diagnostic Interface
The MCZ33812EK's ISO 9141 K-Line transceiver integrates the physical layer for OBD-II diagnostic communication on small-engine ECUs, with internal current limiting and slope control for robust signaling on noisy 12 V vehicle buses. Using a simple external pull-up resistor to VSUP, the IC complies with the ISO 9141-2 standard used for motorcycle and small-displacement vehicle diagnostics. Compared to a discrete K-Line transceiver plus external protection, the integrated block reduces BOM by 4–6 parts and improves ESD/EMC robustness because the driver stages share a common substrate with the ECU ground. For dual-K-Line or CAN-based diagnostics, an external NXP TJA1027 or MC33661 can be added.
Recommended
Off-Road ATV / UTV Engine Control
In ATV, UTV, and snowmobile EFI systems, the MCZ33812EK survives harsh -40 °C cold-start cranking and high-voltage load-dump transients thanks to its 4.7 V–36 V supply range and -40 °C to +125 °C automotive grade. The exposed-pad SOIC-32 keeps junction temperature in range when the ATV is operated continuously at low speed with all three drivers switching under heavy fuel demand. The integrated watchdog and K-Line support dealer-level diagnostics without external supervisor or transceiver ICs. Designers typically pair the MCZ33812EK with an NXP S12 or S08 MCU in a single small ECU housing strapped to the engine case.
Recommended
Portable Two-Stroke EFI Retrofit
Retrofit two-stroke EFI conversion kits use the MCZ33812EK as a compact engine-management module because it integrates injection drivers, ignition pre-driver, 5 V pre-regulator, watchdog, and K-Line diagnostics in one 32-pin device. The 4.7 V–36 V supply tolerates the wide voltage swing of small lithium or lead-acid packs used in portable two-stroke applications. The three low-side outputs cover main and auxiliary injector plus a fuel-pump relay, while the ignition pre-driver handles a wasted-spark or capacitive-discharge coil driver. At roughly 150 mm² of board area, the MCZ33812EK-based ECU can fit inside a backpack-sized control pack for experimental two-stroke conversions.
Recommended
Recommended Products Summary
Engineering reference data for MCZ33812EK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MCZ33812EK/R2 | MCZ33812AEK | MC33812EK | MCZ33812EKR2 |
|---|---|---|---|---|---|
| Package | SOIC-32-EP (0.65 mm pitch) | SOIC-32-EP - same | SOIC-32-EP - same | SOIC-32-EP - same | SOIC-32-EP - same |
| Brand | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors | NXP Semiconductors |
| Supply Voltage Range | 4.7 V to 36 V | 4.7 V to 36 V | 4.7 V to 36 V | 4.7 V to 36 V | 4.7 V to 36 V |
| Low-Side Driver Outputs | 3 × 1 A | 3 × 1 A | 3 × 1 A | 3 × 1 A | 3 × 1 A |
| Integrated +5 V VCC Pre-Regulator | Yes | Yes | Yes | Yes | Yes |
| K-Line (ISO 9141) Transceiver | Yes | Yes | Yes | Yes | Yes |
| Watchdog Timer | Yes | Yes | Yes | Yes | Yes |
| MCU Interface | Parallel | Parallel | Parallel | Parallel | Parallel |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C |
| Target Market | 1-/2-cyl motorcycle EFI | 1-/2-cyl motorcycle EFI | 1-/2-cyl motorcycle EFI | 1-/2-cyl motorcycle EFI | 1-/2-cyl motorcycle EFI |
Key Differentiators
- Three integrated 1 A low-side drivers on one die (vs Generic motor driver ICs that offer single-channel 1–3 A drivers)
- Integrated ISO 9141 K-Line + watchdog + 5 V pre-regulator (vs Discrete ECU solution built from MAX3314/TJA1027 + MAX6752 supervisor + LM2931 regulator)
- Automotive-grade temperature rating with 36 V load-dump margin (vs Industrial-grade motor driver ICs rated to 30 V or below)
- Family of variants with identical pinout (vs Single-source dedicated ignition ICs without same-package siblings)
Design Notes
Solder the exposed thermal pad of the SOIC-32-EP to a copper pour of at least 1 square inch (~6.5 cm²) on the top PCB layer, with thermal vias to inner ground planes. At maximum load with all three 1 A low-side drivers switching continuously (e.g., during a cold-start injection sequence of a 1-cylinder EFI), junction-to-ambient thermal resistance rises sharply without adequate copper. For continuous operation near 1 A per channel, active airflow or a small aluminum spreader is recommended. Estimated: with 2 oz copper and ~1.5 in² pad, theta_JA drops to roughly 35 °C/W, keeping Tj below 125 °C at 35 V × 3 A worst case.
Add a reverse-battery and load-dump protection network on VSUP because the absolute-maximum rating of the IC is 36 V (positive transients). Use a unidirectional 30 V TVS diode rated for 400 A peak (such as SMBJ30A) placed within 5 mm of the VSUP pins, in series with a reverse-polarity Schottky or P-FET. Bypass VSUP locally with a 10 µF X7R ceramic plus a 100 µF aluminum polymer bulk capacitor to absorb injector flyback energy. Estimated suppression: with 30 V TVS the VSUP pin stays below the 36 V datasheet absolute-maximum even under ISO 7637-2 load-dump pulses.
Place the VCC decoupling capacitor (typically 1 µF X7R) and the VSUP bulk capacitor as close as possible to their respective pins and the exposed pad to minimize switching transients on the +5 V MCU supply. Keep the analog ground (GND) and power ground (PGND) star-routed back to a single point under the exposed pad to avoid digital currents injecting noise into the K-Line driver. The K-Line trace should be guarded with a chassis-ground shield or routed adjacent to the chassis return to meet CISPR 25 Class B emissions on motorcycle electrical harnesses.
The TEST pin (pin 30) MUST be left floating or grounded per NXP datasheet instructions - leaving it open-circuited with long PCB traces can inject noise into the analog blocks during production. Do not exceed 36 V on VSUP, even briefly; typical 12 V load-dump pulses can reach ~35 V, leaving only a 1 V margin - always include the TVS as noted in the power design rule above. When migrating from MCZ33812EK to MCZ33812AEK or vice-versa, confirm watchdog timing and K-Line current-limit thresholds against the latest datasheet revision because minor parametric differences have been observed.
Because the MCZ33812EK contains both switching power drivers (1 A low-side outputs) and an ISO 9141 K-Line transceiver, the ECU PCB must separate the power ground (PGND) and analog ground (GND) nets, joining them only at the exposed pad. Add an RC snubber (4.7 Ω + 10 nF) across each low-side output to damp injector flyback ringing below 100 MHz, which is the dominant source of CISPR 25 radiated emissions on motorcycle EFI modules. For projects requiring CISPR 25 Class 5, consider adding a small common-mode choke on the VSUP and K-Line cables.
Compliance Information
RoHS compliant per NXP product page and DigiKey package marking 'ROHS COMPLIANT, SOIC-32 0.65 MM PITCH'. AEC-Q100 status is not explicitly listed in the snapshot datasheet captured - treated as 'not_applicable' for this record; automotive temperature grade is qualified under NXP's automotive flow but full AEC-Q100 document should be requested separately. Lead-free / halogen-free per package marking on the manufacturer's data sheet.
