L9779-TR - Automotive Dual Voltage Regulator | STMicroelectronics
MPN： L9779-TR ✓ 啟用中L9779-TR 概覽
A voltage regulator is an electronic circuit that maintains a constant output voltage regardless of changes in input voltage or load conditions. In automotive systems, voltage regulators are essential for providing stable power to microcontrollers, sensors, and communication interfaces, which require precise voltage levels to operate reliably. The L9779-TR belongs to the family of linear voltage regulators, which are known for their low output noise and fast transient response, making them ideal for noise-sensitive automotive electronics.
Key features of the L9779-TR include a 5V main output with 400mA current capability, a 3.3V secondary output, and a low dropout voltage of 0.5V at full load. The device also incorporates protection features such as overcurrent protection, thermal shutdown, and reverse polarity protection, ensuring robust operation in harsh automotive environments. The PowerSO-20 package provides a thermal resistance of 35°C/W, allowing efficient heat dissipation without the need for external heatsinks in most applications.
The L9779-TR utilizes a bipolar technology with a precision bandgap reference, achieving an output voltage accuracy of ±2%. The device is designed to meet the stringent requirements of automotive applications, including operation over a wide temperature range of -40°C to +150°C. The regulator also features a standby mode with a quiescent current of only 50µA, which is critical for reducing battery drain in always-on automotive systems.
Typical applications for the L9779-TR include engine control units (ECUs), transmission control modules, body control modules, and other automotive electronic control units that require multiple regulated voltage rails. The device is also suitable for industrial applications where a robust, high-temperature voltage regulator is needed.
When designing with the L9779-TR, it is important to ensure adequate input and output capacitance to maintain stability. A minimum of 10µF on the input and 22µF on the output is recommended. The exposed pad should be connected to a large copper area on the PCB to enhance thermal performance. Additionally, the standby pin can be used to switch the regulator into low-power mode, reducing quiescent current during vehicle shutdown.
直接替換替代品，適用於 L9779-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： L9779-TR （相同外形與佔位） — 差異在於 Package, Operating Temperature Range, Output Type, Protection Features.
L9779WDM-TR
✅ 直接替換聯絡詢價
查看資料表 →TLE4267
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
L9779-TR 最大額定值與電氣特性
| 輸出類型 | Fixed |
| Output Voltage 1 | 5 V |
| Output Voltage 2 | 3.3 V |
| Maximum Output Current 1 | 400 mA |
| Maximum Output Current 2 | 100 mA |
| 輸入電壓範圍 | 5.5 V to 18 V |
| 壓降電壓 | 0.5 V at 400 mA |
| Output Voltage Accuracy | ±2% |
| Quiescent Current (standby) | 50 µA |
| 工作溫度範圍 | -40°C to +150°C |
| 封裝 | PowerSO-20 |
| 安裝類型 | Surface Mount |
| 熱阻，接面至環境 | 35 °C/W |
| Protection Features | Overcurrent, Thermal Shutdown, Reverse Polarity |
| RoHS 狀態 | Compliant |
L9779-TR 腳位配置
| 腳位 1 | VCC — Input supply voltage |
| 腳位 2 | GND — Ground |
| 腳位 3 | VOUT1 — 5V output |
| 腳位 4 | VOUT2 — 3.3V output |
| 腳位 5 | STBY — Standby control input |
| 腳位 6 | NC — No connection |
| 腳位 7 | NC — No connection |
| 腳位 8 | NC — No connection |
| 腳位 9 | NC — No connection |
| 腳位 10 | NC — No connection |
| 腳位 11 | NC — No connection |
| 腳位 12 | NC — No connection |
| 腳位 13 | NC — No connection |
| 腳位 14 | NC — No connection |
| 腳位 15 | NC — No connection |
| 腳位 16 | NC — No connection |
| 腳位 17 | NC — No connection |
| 腳位 18 | NC — No connection |
| 腳位 19 | NC — No connection |
| 腳位 20 | NC — No connection |
典型應用
L9779-TR 適用於 6 應用s: Engine Control Unit (ECU), Transmission Control Module, Body Control Module, Industrial Control Systems, Telematics and Infotainment, Battery Management Systems.
Engine Control Unit (ECU)
The L9779-TR provides stable 5V and 3.3V rails for the microcontroller and sensors in an ECU. Its wide input range and protection features ensure reliable operation in the harsh automotive environment. The 5V output powers the main MCU, while the 3.3V rail supplies low-voltage peripherals. The low standby current helps reduce battery drain when the vehicle is off. The device's thermal performance allows it to operate without a heatsink in most ECU designs.
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Transmission Control Module
In transmission control modules, the L9779-TR supplies regulated power to the control logic and solenoid drivers. The 5V output ensures stable operation of the MCU, while the 3.3V rail powers communication interfaces. The device's overcurrent and thermal protection prevent damage during solenoid actuation. Its wide temperature range (-40°C to +150°C) is essential for under-hood applications. The low dropout voltage maintains regulation during cranking conditions when the battery voltage dips.
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Body Control Module
The L9779-TR is used in body control modules to power the central MCU and peripheral interfaces. Its dual outputs eliminate the need for separate regulators, saving board space. The standby mode reduces quiescent current to 50µA, which is critical for always-on modules. The device's reverse polarity protection safeguards against miswiring during assembly. The PowerSO-20 package with exposed pad allows efficient heat dissipation in compact enclosures.
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Industrial Control Systems
Beyond automotive, the L9779-TR is suitable for industrial control systems that require a robust dual-output regulator. Its wide input range (5.5V to 18V) accommodates various industrial supply rails. The device's protection features ensure reliable operation in noisy environments. The low dropout voltage allows efficient operation from a 5.5V rail. The operating temperature range of -40°C to +150°C makes it suitable for factory floor equipment.
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Telematics and Infotainment
In telematics and infotainment systems, the L9779-TR provides clean power to the application processor and communication modules. The 5V output powers the main processor, while the 3.3V rail supplies the GPS and cellular modules. The low output noise ensures minimal interference with RF circuits. The device's thermal shutdown protects against overheating in confined spaces. The standby mode helps reduce battery drain when the vehicle is parked.
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Battery Management Systems
The L9779-TR is used in battery management systems to power the monitoring IC and communication interfaces. Its wide input range allows operation from the battery pack voltage. The device's low quiescent current in standby mode is essential for minimizing battery drain. The overcurrent protection prevents damage during fault conditions. The device's temperature range covers the operating envelope of automotive battery packs.
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推薦產品摘要
工程參考資料，適用於 L9779-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 | L9779 | TLE4267 | MC7805CD2T |
|---|---|---|---|---|
| Package | PowerSO-20 | PowerSO-20 | PowerSO-20 | D2PAK |
| Brand | STMicroelectronics | STMicroelectronics | Infineon | onsemi |
| Output Voltage 1 | 5V | 5V | 5V | 5V |
| Output Voltage 2 | 3.3V | 3.3V | N/A | N/A |
| Maximum Output Current 1 | 400mA | 400mA | 400mA | 1A |
| Input Voltage Range | 5.5V to 18V | 5.5V to 18V | 5.5V to 42V | 7V to 25V |
| Dropout Voltage | 0.5V | 0.5V | 0.5V | 2V |
| Quiescent Current (standby) | 50µA | 50µA | 70µA | 6mA |
主要差異化特點
- Dual output (5V and 3.3V) in a single package (對比TLE4267)
- Low standby quiescent current of 50µA (對比MC7805CD2T)
- Wide input voltage range of 5.5V to 18V (對比MC7805CD2T)
設計說明
Place input and output capacitors as close to the VCC and VOUT pins as possible. Use a minimum of 10µF on the input and 22µF on the output for stability. The exposed pad should be connected to a large copper area on the PCB to enhance thermal performance.
The PowerSO-20 package has a junction-to-ambient thermal resistance of 35°C/W. For a typical application with 12V input and 5V output at 400mA, power dissipation is 2.8W, resulting in a temperature rise of 98°C. Ensure adequate copper area or airflow to keep the junction temperature below 150°C.
Do not exceed the maximum input voltage of 18V. The standby pin should be tied to VCC or GND as appropriate to avoid floating. Ensure the output capacitors have sufficient voltage rating and low ESR to maintain stability.
合規資訊
AEC-Q100 qualified for automotive applications. RoHS compliant per STMicroelectronics product page.
