L9779WD-TR - Multifunction Engine Management PMIC | STMicroelectronics
MPN: L9779WD-TR ✓ NakahandaL9779WD-TR Ulas
A multifunction PMIC for engine management is a mixed-signal IC that consolidates the analog and power stages required to run a gasoline or diesel Engine Control Unit (ECU). In modern ECUs it sits between the 12 V or 24 V battery rail and the microcontroller, providing regulated sensor rails, driving low-side and high-side injector stages, controlling lamp/relay pre-drivers, and supervising battery/ignition lines. This category falls within the broader PMIC family and the wider automotive power-management domain, and is typically paired with an MCU such as the SPC56 or SPC58 series in safety-relevant powertrain systems.
Key features include five 5 V sensor supplies with current limiting, four low-side injector drivers (typically 4 x 1.5 A), four low-side lamp/relay pre-drivers, an ignition KEY_ON input with internal pull-down, an MSC diagnostic interface, and integrated watchdog/reset functionality. The device is qualified to automotive temperature grades and uses BCD6S mixed-signal process technology, giving it tolerance to load-dump transients common on 12 V vehicle buses.
The L9779WD integrates an internal charge pump to drive N-channel FETs, an SPI/MSC configuration block, and a thermal-shutdown block, all sharing a single die. This high level of integration reduces ECU board area versus discrete driver implementations and helps shorten wire-harness routing because the high-current outputs are multiplexed from a single IC.
Typical applications include gasoline and diesel engine ECUs, motorcycle ECUs, powersport vehicle controllers, and small-displacement powertrain modules. The wide operating voltage range and integrated diagnostics make it a common choice where a robust, AEC-Q100-grade power front-end is needed.
When designing with the L9779WD-TR, pay particular attention to thermal layout of the HiQUAD-64 power package: the exposed pad must be soldered to a sufficiently large copper area to keep junction temperature within AEC-Q100 Grade-1 limits at worst-case injector current.
This page synthesizes distributor pricing, MSC vs SPI variant differences, and practical design notes not consolidated in any single manufacturer document.
Mga alternatibo na pwedeng ilagay na L9779WD-TR — parehas na package, pin-to-pin na katugmang. Hindi kasama ang mga bahagi ng iba't-ibang package na nangangailangan ng pagpapaayos ng PCB.
Variante sa Seri na ito
Katulad na modelo sa serye na katugma sa pagpasok L9779WD-TR (parehas na form factor at footprint) — pagkakaiba sa Package, Communication Interface, Operating Temperature Range.
L9779WD-SPI-TR
✅ Drop-InMagkontak para sa presyo
Tingnan ang Datasheet →L9779WD-SPI-TR
✅ Drop-InMagkontak para sa presyo
Tingnan ang Datasheet →L9779WD-SPI-TR
✅ Drop-In ⚠️ Mga Talaan Hindi NaiwerikmoMagkontak para sa presyo
Tingnan ang Datasheet →L9779WD-TR Mga Pinakamataas na Rating at Electrical Characteristics
| Fungsi | Multifunction IC for engine management |
| Topolohiya | Engine Management PMIC with MSC interface |
| Process Technology | BCD6S |
| Supply Voltage (VBAT) | Up to 18 V typ., load-dump tolerant |
| Number of 5 V Sensor Supplies | 5 (current-limited) |
| Injector Low-Side Drivers | 4 x low-side drivers |
| Lamp/Relay Pre-Drivers | 4 x low-side pre-drivers |
| Communication Interface | MSC (L9779WD/-TR); SPI (L9779WD-SPI/-SPI-TR) |
| Watchdog | Yes (integrated) |
| KEY_ON Input | Yes (internal pull-down, external reverse-battery diode) |
| Charge Pump | Yes (internal, for N-channel FET drive) |
| Thermal Shutdown | Yes |
| Packhaging | HiQUAD-64 (power package, exposed pad) |
| Temperature na Operasyon | -40C to +125C (automotive AEC-Q100 grade) |
| Uri ng Pagpapasok | Surface Mount |
| Tindminan RoHS | Compliant |
| Packaging | Tape & Reel (TR suffix) |
Pin Configuration ng L9779WD-TR
| Pin 1 | VB — Battery supply input |
| Pin 2 | VCC5V_1 — 5 V sensor supply output 1 |
| Pin 3 | VCC5V_2 — 5 V sensor supply output 2 |
| Pin 4 | GND — Power ground |
| Pin 5 | KEY_ON — Ignition/wake-up input with internal pull-down |
| Pin 6 | MSC — MSC serial diagnostic interface line |
| Pin 7 | WD_OUT — Watchdog output to host MCU |
| Pin 8 | RESET — Reset output to host MCU |
| Pin 9 | INJ1 — Injector 1 low-side driver |
| Pin 10 | INJ2 — Injector 2 low-side driver |
| Pin 11 | INJ3 — Injector 3 low-side driver |
| Pin 12 | INJ4 — Injector 4 low-side driver |
| Pin 13 | PRE1 — Pre-driver 1 output (lamp/relay) |
| Pin 14 | PRE2 — Pre-driver 2 output (lamp/relay) |
| Pin 15 | PRE3 — Pre-driver 3 output (lamp/relay) |
| Pin 16 | PRE4 — Pre-driver 4 output (lamp/relay) |
| Pin 17 | MRD — Main Relay Driver output |
| Pin 18 | CP — Charge-pump node for N-FET drive |
| Pin 19 | TEMP — Analog temperature sensor output |
| Pin 20 | DIAG — Diagnostic flag output |
| Pin 21-63 | I/O / NC — Various digital I/O, sensor, and supply pins per datasheet pin table |
| Pin 64 | EPAD — Exposed thermal pad (must be soldered to copper) |
Tipikal na mga Gamit
L9779WD-TR ay nararapat para sa 6 aplikasyons: Gasoline Engine ECU Power Stage, Diesel Engine Management ECU, Motorcycle / Powersport ECU, Small-Displacement LPG / CNG ECU, Outboard Marine Engine ECU, Standalone Engine Controller (Industrial / Genset).
Gasoline Engine ECU Power Stage
The L9779WD-TR is the front-end power IC for 4-cylinder gasoline ECUs, providing 5 V sensor rails and 4 low-side injector drivers from a 12 V battery. With 4 integrated injector low-sides and 4 pre-drivers, it can sink the full current budget of a 4-cylinder engine in a single HiQUAD-64 chip, eliminating the need for discrete MOSFET driver stages. The MSC interface lets the host SPC56-class MCU query fault registers and toggle outputs, while the integrated watchdog guarantees MCU sanity.
Inirekomenda
Diesel Engine Management ECU
In diesel ECUs the L9779WD-TR drives the injectors and provides conditioned sensor supplies for rail-pressure and pedal-position sensors. Its load-dump-tolerant front-end is rated for 12 V and 24 V commercial-vehicle buses, and the BCD6S process gives the ruggedness needed for solenoid driver PWM operation. The integrated 5 V sensor rails feed the rail-pressure and crank-position sensors that close the diesel injection control loop.
Inirekomenda
Motorcycle / Powersport ECU
Single- and twin-cylinder motorcycle ECUs use the L9779WD-TR to combine injection, sensor supply, and lamp driving on a compact board. The HiQUAD-64 footprint is small enough to fit inside a sealed ECU enclosure, and the integrated 4 injector channels cover the full injection complement of most powersport engines. Key_on wake-up behavior matches the ignition-switched supply common in two-wheeler wiring harnesses.
Inirekomenda
Small-Displacement LPG / CNG ECU
Alternative-fuel ECUs for LPG and CNG conversions use the L9779WD-TR to drive gas-injector low-sides and the host of 5 V sensors required for closed-loop lambda control. The 4-injector channel count typically matches the 4-cylinder LPG arrangement, and the integrated current-limited sensor rails simplify the lambda and MAP-sensor biasing. Its automotive temperature grade supports under-hood mounting near the gas rail.
Inirekomenda
Outboard Marine Engine ECU
Marine outboard ECUs operate in a harsher thermal and humidity environment and benefit from the L9779WD-TR's -40C to +125C operating grade and sealed HiQUAD-64 power package. The integrated sensor supplies drive crank-position and temperature sensors while the lamp/relay pre-drivers control warning indicators and fuel-pump relays. The exposed thermal pad is soldered to the chassis for direct heat-sinking into the engine block.
Inirekomenda
Standalone Engine Controller (Industrial / Genset)
Standalone industrial engine controllers for gensets and pumps adopt the L9779WD-TR as the front-end driver, taking advantage of its 5 V sensor rails and integrated pre-drivers to drive starter relays and shutdown solenoids. The KEY_ON input maps cleanly onto a keyswitch signal, and the MSC diagnostic bus allows the supervisor PLC to read fault flags. Industrial vibration profiles are well within the HiQUAD-64 mechanical rating.
Inirekomenda
Buod ng mga Inirekomendang Produkto
Impormasyon ng Talumpati sa Engineering for L9779WD-TR — ikabit, gabay sa disenyo, at impormasyon ng pagsunod sa kautusan.
Paunawang Hanapin
Ikabit sa Mga Alternatibo
| Parametro | Ito ang Producto | L9779WD | L9779WD-SPI-TR | L9779WD-SPI |
|---|---|---|---|---|
| Package | HiQUAD-64 | HiQUAD-64 (same) | HiQUAD-64 (same) | HiQUAD-64 (same) |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Serial Interface | MSC | MSC | SPI | SPI |
| Packaging | Tape & Reel (TR) | Tube / Tray | Tape & Reel | Tube / Tray |
| Injector Low-Side Drivers | 4 | 4 | 4 | 4 |
| Lamp/Relay Pre-Drivers | 4 | 4 | 4 | 4 |
| 5 V Sensor Supplies | 5 | 5 | 5 | 5 |
| Process Technology | BCD6S | BCD6S | BCD6S | BCD6S |
Pangunahing mga Pagkakaiba
- MSC vs SPI variant on identical silicon (kumpara saL9779WD-SPI-TR)
- Tape-and-reel packaging for high-volume assembly (kumpara saL9779WD)
- Integrated 5 V sensor supplies reduce BOM (kumpara saL9779WD-SPI)
Talaan ng Disenyo
The HiQUAD-64 exposed thermal pad is the primary heat-dissipation path for the L9779WD-TR. At full load with 4 injectors pulling peak current, internal dissipation can exceed several watts. Solder the EPAD to a copper pour of at least 1 square inch on top and bottom layers, stitched with thermal vias, to keep junction temperature below the +150C shutdown threshold across the -40C to +125C operating range.
Place the bulk VBAT decoupling capacitor (>=47 uF) within 5 mm of the VB pin and use a wide PCB trace rated for the worst-case injector current (typically 4 x 1.5 A peak). Keep the KEY_ON input trace short and route the MSC line away from the injector switching nodes to avoid coupling noise into the diagnostic bus. The exposed pad must be a solid copper region with no signal traces crossing it.
Do not operate the L9779WD-TR without an external reverse-battery protection diode on KEY_ON, otherwise the internal pull-down structure can be damaged during a jump-start event. Also ensure the MSC pull-up resistor matches the host MCU's logic level (typically 5 V); a wrong pull-up value causes intermittent communication loss in production. Verify watchdog timing in firmware against the datasheet's tWD specification before locking the design.
Impormasyon ng Pagsunod sa Kautusan
Automotive-grade part per STMicroelectronics product family. Confirm latest PPAP and IMDS filings with ST FAE before design-in for series production.
