L9779WD-TR - Multifunction Engine Management PMIC | STMicroelectronics
MPN： L9779WD-TR ✓ 啟用中L9779WD-TR 概覽
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.
直接替換替代品，適用於 L9779WD-TR — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： L9779WD-TR （相同外形與佔位） — 差異在於 Package, Communication Interface, Operating Temperature Range.
L9779WD-SPI-TR
✅ 直接替換聯絡詢價
查看資料表 →L9779WD-SPI-TR
✅ 直接替換聯絡詢價
查看資料表 →L9779WD-SPI-TR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →L9779WD-TR 最大額定值與電氣特性
| 功能 | Multifunction IC for engine management |
| 拓撲 | 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) |
| 過熱關機 | Yes |
| 封裝 | HiQUAD-64 (power package, exposed pad) |
| 工作溫度 | -40C to +125C (automotive AEC-Q100 grade) |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
| Packaging | Tape & Reel (TR suffix) |
L9779WD-TR 腳位配置
| 腳位 1 | VB — Battery supply input |
| 腳位 2 | VCC5V_1 — 5 V sensor supply output 1 |
| 腳位 3 | VCC5V_2 — 5 V sensor supply output 2 |
| 腳位 4 | GND — Power ground |
| 腳位 5 | KEY_ON — Ignition/wake-up input with internal pull-down |
| 腳位 6 | MSC — MSC serial diagnostic interface line |
| 腳位 7 | WD_OUT — Watchdog output to host MCU |
| 腳位 8 | RESET — Reset output to host MCU |
| 腳位 9 | INJ1 — Injector 1 low-side driver |
| 腳位 10 | INJ2 — Injector 2 low-side driver |
| 腳位 11 | INJ3 — Injector 3 low-side driver |
| 腳位 12 | INJ4 — Injector 4 low-side driver |
| 腳位 13 | PRE1 — Pre-driver 1 output (lamp/relay) |
| 腳位 14 | PRE2 — Pre-driver 2 output (lamp/relay) |
| 腳位 15 | PRE3 — Pre-driver 3 output (lamp/relay) |
| 腳位 16 | PRE4 — Pre-driver 4 output (lamp/relay) |
| 腳位 17 | MRD — Main Relay Driver output |
| 腳位 18 | CP — Charge-pump node for N-FET drive |
| 腳位 19 | TEMP — Analog temperature sensor output |
| 腳位 20 | DIAG — Diagnostic flag output |
| 腳位 21-63 | I/O / NC — Various digital I/O, sensor, and supply pins per datasheet pin table |
| 腳位 64 | EPAD — Exposed thermal pad (must be soldered to copper) |
典型應用
L9779WD-TR 適用於 6 應用s: 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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
推薦產品摘要
工程參考資料，適用於 L9779WD-TR — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- MSC vs SPI variant on identical silicon (對比L9779WD-SPI-TR)
- Tape-and-reel packaging for high-volume assembly (對比L9779WD)
- Integrated 5 V sensor supplies reduce BOM (對比L9779WD-SPI)
設計說明
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.
合規資訊
Automotive-grade part per STMicroelectronics product family. Confirm latest PPAP and IMDS filings with ST FAE before design-in for series production.
