L9984 - Automotive Quad Low-Side Driver | STMicroelectronics
MPN: L9984 ✓ Hoạt độngL9984 Tóm tắt
A low-side driver is a type of power switch that connects the load to ground when activated, allowing the microcontroller to control high-side loads through a simple logic interface. In automotive systems, low-side drivers are essential for controlling actuators, lights, and motors, where the load is connected between the battery positive terminal and the driver output. The L9984 belongs to the family of smart power switches, which integrate protection and diagnostic features to enhance system reliability and reduce external component count.
Key features of the L9984 include overcurrent protection, thermal shutdown, and undervoltage lockout, ensuring safe operation under fault conditions. Each channel has an open-load detection capability, which is critical for diagnosing wiring faults in automotive harnesses. The device also features a serial peripheral interface (SPI) for advanced diagnostics and control, allowing the microcontroller to read fault status and control each output independently. The outputs are protected against short-circuit and over-temperature, with a typical overcurrent threshold of 2.5A per channel.
The L9984 utilizes a robust BCD (Bipolar-CMOS-DMOS) technology, which combines the benefits of bipolar analog circuits, CMOS logic, and DMOS power transistors. This technology enables high current handling with low on-resistance, typically 0.5 ohm per channel, minimizing power dissipation and improving efficiency. The device is designed to operate over the automotive temperature range of -40°C to +150°C, making it suitable for under-hood applications. The PowerSO-20 package with exposed pad provides a low thermal resistance of 35°C/W, allowing efficient heat dissipation without external heatsinks in moderate power applications.
Typical applications include automotive body control modules, lighting control, relay drivers, and solenoid drivers in transmission control units. The L9984 is also used in industrial automation for driving valves and actuators, where its robust protection features ensure reliable operation in harsh environments. The SPI interface enables seamless integration with microcontrollers, providing real-time diagnostics and reducing wiring complexity.
When designing with the L9984, it is essential to ensure proper PCB layout with adequate copper area for heat dissipation, especially when driving multiple channels at high current. The exposed pad should be connected to the ground plane with multiple vias to enhance thermal performance. Additionally, the SPI lines should be kept short and shielded to minimize electromagnetic interference, and the supply voltage should be decoupled with a 100nF ceramic capacitor close to the VCC pin.
Bộ thay thế dễ dàng lắp đặt cho L9984 — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với L9984 (cùng hình factor và footprint) — khác nhau ở On-Resistance (per channel), Operating Temperature Range, Output Current per Channel, Protection Features, Supply Voltage Range.
L9985
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →VNQ7004
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
BTS7008
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
L9984 Tỷ lệ tối đa & tính chất điện
| Number of Channels | 4 |
| Supply Voltage Range | 4.5 V to 40 V |
| Output Current per Channel | 1.5 A (continuous) |
| On-Resistance (per channel) | 0.5 ohm (typical) |
| Overcurrent Threshold | 2.5 A (typical) |
| Khoảng nhiệt độ hoạt động | -40°C to +150°C |
| Hộp | PowerSO-20 |
| Kiểu lắp đặt | Surface Mount |
| Kháng nhiệt, mối nối đến môi trường | 35 °C/W |
| Giao diện | SPI |
| Protection Features | Overcurrent, thermal shutdown, undervoltage lockout, open-load detection |
| Kiểu đầu ra | Low-side |
| Logic Input Voltage | 3.3 V / 5 V compatible |
| Trạng thái RoHS | Compliant |
| AEC-Q100 Qualified | Yes |
Cấu hình chân L9984
| Chân 1 | OUT1 — Low-side output channel 1 |
| Chân 2 | OUT2 — Low-side output channel 2 |
| Chân 3 | OUT3 — Low-side output channel 3 |
| Chân 4 | OUT4 — Low-side output channel 4 |
| Chân 5 | GND — Ground |
| Chân 6 | VCC — Supply voltage |
| Chân 7 | SCK — SPI clock |
| Chân 8 | SDI — SPI data input |
| Chân 9 | SDO — SPI data output |
| Chân 10 | CS — SPI chip select |
| Chân 11 | IN1 — Logic input for channel 1 |
| Chân 12 | IN2 — Logic input for channel 2 |
| Chân 13 | IN3 — Logic input for channel 3 |
| Chân 14 | IN4 — Logic input for channel 4 |
| Chân 15 | NC — Not connected |
| Chân 16 | NC — Not connected |
| Chân 17 | NC — Not connected |
| Chân 18 | NC — Not connected |
| Chân 19 | NC — Not connected |
| Chân 20 | NC — Not connected |
Ứng dụng tiêu biểu
L9984 phù hợp cho 6 Áp dụngs: Automotive Body Control Module, Lighting Control, Relay Driver, Solenoid Driver in Transmission Control, Industrial Automation, LED Lighting Modules.
Automotive Body Control Module
The L9984 is used in body control modules to drive exterior and interior lighting, relays for power windows, and door locks. Its four channels allow independent control of multiple loads, while the SPI interface provides diagnostics for fault detection. The wide supply voltage range (4.5V to 40V) accommodates both 12V and 24V automotive systems, and the AEC-Q100 qualification ensures reliability in harsh environments. The overcurrent and thermal protection prevent damage to the module and wiring, making it ideal for centralized body electronics.
Được đề xuất
Lighting Control
The L9984 can drive automotive lighting such as headlamps, tail lamps, and interior lights. Each channel can sink up to 1.5A, sufficient for incandescent bulbs and LED modules with current limiting. The open-load detection feature is particularly useful for detecting burnt-out bulbs, enabling the system to alert the driver. The device's thermal shutdown protects against over-temperature when driving high-power lamps, and the SPI interface allows dimming control via PWM signals from the microcontroller.
Được đề xuất
Relay Driver
The L9984 is ideal for driving relays in automotive and industrial systems. Its low on-resistance (0.5 ohm) minimizes voltage drop across the switch, ensuring reliable relay operation. The built-in clamping diodes handle inductive kickback when the relay coil is de-energized, protecting the driver from voltage spikes. The overcurrent protection prevents damage if a relay coil shorts, and the SPI interface enables monitoring of each relay's status. This makes the L9984 a robust solution for controlling motors, heaters, and other high-current loads through relays.
Được đề xuất
Solenoid Driver in Transmission Control
In automatic transmissions, the L9984 drives solenoids that control hydraulic pressure for gear shifting. The device's fast switching capability and low on-resistance ensure precise control of solenoid current, which is critical for smooth gear changes. The thermal shutdown protects the driver in high-temperature transmission environments, and the SPI interface provides real-time diagnostics for solenoid health. The AEC-Q100 qualification ensures long-term reliability in this demanding application.
Được đề xuất
Industrial Automation
The L9984 is used in industrial automation to drive valves, actuators, and solenoids in process control systems. Its wide supply voltage range (4.5V to 40V) makes it compatible with 24V industrial power supplies. The robust protection features (overcurrent, thermal shutdown) ensure reliable operation in harsh factory environments. The SPI interface allows seamless integration with PLCs and industrial microcontrollers, enabling centralized control and diagnostics. The PowerSO-20 package with exposed pad provides efficient heat dissipation for continuous operation.
Được đề xuất
LED Lighting Modules
The L9984 can drive LED lighting modules in automotive and industrial applications. Each channel can sink up to 1.5A, which is sufficient for high-power LEDs when used with appropriate current-limiting resistors or LED drivers. The open-load detection feature helps identify faulty LED strings, simplifying maintenance. The device's thermal shutdown protects against over-temperature when driving multiple LEDs, and the SPI interface allows individual channel control for dynamic lighting effects. This makes the L9984 a versatile solution for LED lighting systems.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho L9984 — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | L9985 | VNQ7004 | BTS7008 |
|---|---|---|---|---|
| Package | PowerSO-20 | PowerSO-20 | PowerSO-20 | PowerSO-20 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | Infineon |
| Number of Channels | 4 | 4 | 4 | 4 |
| Output Current per Channel | 1.5 A | 2 A | 1.5 A | 1.5 A |
| On-Resistance | 0.5 ohm | 0.3 ohm | 0.5 ohm | 0.4 ohm |
| Supply Voltage Range | 4.5V to 40V | 4.5V to 40V | 4.5V to 40V | 4.5V to 40V |
| Interface | SPI | SPI | SPI | SPI |
| Protection Features | Overcurrent, thermal shutdown, UVLO, open-load | Overcurrent, thermal shutdown, UVLO, open-load | Overcurrent, thermal shutdown, UVLO, open-load | Overcurrent, thermal shutdown, UVLO, open-load |
Bảo phân biệt quan trọng
- Higher output current capability (vsL9985)
- Lower on-resistance (vsBTS7008)
- Same-brand compatibility (vsBTS7008)
Ghi chú thiết kế
The L9984 in PowerSO-20 package has a junction-to-ambient thermal resistance of 35°C/W. When driving all four channels at 1.5A each with a supply voltage of 13.5V and load resistance of 9 ohm, the power dissipation per channel is approximately 1.125W (I^2 * R_on = 1.5^2 * 0.5). Total dissipation is 4.5W, resulting in a junction temperature rise of 157.5°C above ambient. For reliable operation, ensure adequate PCB copper area and consider using the exposed pad with thermal vias to reduce thermal resistance.
Place a 100nF ceramic capacitor close to the VCC pin and a 10uF electrolytic capacitor for bulk decoupling. The exposed pad should be soldered to a large ground plane with multiple vias to enhance heat dissipation. Keep SPI traces short and shielded to minimize EMI, and route them away from high-current output traces to avoid coupling.
Do not exceed the absolute maximum supply voltage of 40V. Ensure the logic inputs are not left floating; use pull-up or pull-down resistors as needed. When driving inductive loads, the internal clamping diodes handle kickback, but for high-energy loads, external TVS diodes may be required. Also, verify the SPI communication timing to avoid data corruption.
Thông tin tuân thủ
AEC-Q100 qualified per STMicroelectronics product page. RoHS compliant.
