I. Scenario Positioning and Core Value (Addressing the Pain Points of In-Vehicle Power Supplies)

　　The 9-60V DC-DC 300W in-vehicle switching power supply is a core power supply for automotive electronic systems. Suitable for passenger cars (12V system), commercial vehicles (24V system), new energy light trucks (48V system), and special vehicles (with a wide voltage requirement), it provides stable DC power for in-vehicle navigation, dashcams, refrigerators, communication modules (4G/5G), ADAS driver assistance devices, and more. It addresses four core pain points of traditional in-vehicle power supplies:

　　Difficulty adapting to voltage fluctuations: Voltage drops during vehicle start-up and shutdown (e.g., a 12V system drops to 9V) and voltage spikes during sudden load changes (e.g., a commercial vehicle generator overloads to 60V). Conventional power supplies (with an input range of 12-24V) are prone to triggering protective shutdowns, causing device power outages.

　　Insufficient power and poor load carrying: When multiple devices are operating simultaneously (e.g., navigation, refrigerator, and dashcam), the total power demand reaches... 250-300W. Traditional low-power power supplies (≤200W) are prone to overload and trigger overheating protection.

　　Poor tolerance to the in-vehicle environment: Strong vibrations during driving (such as bumpy roads) can loosen power supply components. High temperatures near the engine compartment (≥80°C) and low temperatures in northern winter (≤-30°C) can cause power supply efficiency to drop sharply, or even fail.

　　Significant EMC interference: Power supply switching noise can easily interfere with the vehicle's ECU, radio, and radar systems, causing false alarms on the dashboard fault light and interrupting communication signals. This power supply delivers four core benefits through its "9-60V wide input, 300W stable output, and automotive-grade reliability design":

　　Full Voltage Coverage: 9-60V input adapts to 12V/24V/48V in-vehicle systems. Stable output is maintained even during start-stop voltage drops to 9V and transient spikes to 60V, preventing device power outages.

　　High Power Capacity: 300W rated output (360W peak) can simultaneously power 3-5 in-vehicle devices, meeting the needs of multi-load collaboration.

　　Extreme Environment Tolerance: -40-85°C wide operating temperature range, 10-2000Hz strong vibration tolerance, and IP65 dust and water resistance make it suitable for installation in various locations, including the engine compartment, underbody, and cab.

　　Low EMC: Compliant with CISPR 25 automotive EMC standards, switching noise suppression is ≤55dBμV, minimizing interference with sensitive in-vehicle electronic equipment. II. Core Performance Parameters (Adaptation to Vehicle Power Supply Requirements)

　　(I) Input and Output Characteristics (Core Adaptability Indicators)

　　Wide Voltage Input: Input voltage range 9-60V DC, supporting 12V passenger cars (idle 13.5V, start-stop 9-14.5V), 24V commercial vehicles (normal 27V, charging 32V), and 48V new energy light trucks (operating 45-54V). It withstands transient input voltage spikes of 60V (lasting 100ms) without damage.

　　Power and Output Regulation: Rated output power 300W, peak power 360W (lasting 30s to cope with device startup shock). Output voltage can be customized to 12V/24V/5V (common specifications). Output current corresponds to 25A (12V), 12.5A (24V), 60A (5V), output voltage accuracy ≤±1% (at full load);

　　Conversion efficiency: ≥90% at typical load (50%-100%), ≥85% at light load (20%), standby power consumption ≤0.5W (to prevent battery drain after the vehicle is turned off). (II) In-Vehicle Environment Compatibility

　　Temperature Tolerance: Operating temperature: -40°C to 85°C (no startup delay at -40°C, no overheat protection at full load at 85°C); Storage temperature: -55°C to 125°C; output voltage fluctuation ≤±0.5% after 4 hours of continuous operation at 85°C;

　　Vibration Resistance and Protection: Vibration resistance meets ISO 16750-3 standards, with 10g acceleration in the 10-500Hz frequency range and 5g acceleration in the 500-2000Hz frequency range (8 hours each on the X/Y/Z axes), ensuring no loose components and uninterrupted output; Protection rating: IP65 (compliant with GB/T 4208), dustproof (prevents intrusion of dust particles ≥12.5μm) and water jet-proof (no damage from water jets from any direction), suitable for the humid and dusty environment of the engine compartment;

　　Electromagnetic Compatibility (EMC): Radiated interference complies with CISPR 25 Class 3 (30MHz-1GHz) Frequency band ≤54dBμV/m), conducted disturbances comply with CISPR 25 Class 2 (≤60dBμV in the 150kHz-30MHz frequency band); electromagnetic interference (EMI) compliance with ISO 11452-2, with no interference to on-board ECUs and radar systems.

　　(III) Safety and Protection Features

　　Multiple protections: Overvoltage protection (threshold 14.5-15.5V at 12V output voltage), overcurrent protection (triggered at 1.2-1.5 times the rated current), overtemperature protection (shutdown when heatsink temperature ≥105°C, automatic recovery when ≤90°C), short-circuit protection (immediate shutdown in the event of an output short, automatic recovery after the short is removed), and reverse polarity protection (no damage or output if the input polarity is reversed).

　　Reliability: Mean Time Between Failures (MTBF) ≥100,000 hours (compliant with MIL-HDBK-217F standard), service life ≥8 years (matching the vehicle lifecycle). III. Core Technology Implementation Path (Ensuring In-Vehicle Reliability)

　　(I) Wide Voltage Input and High Power Density Design

　　Topology Optimization: Utilizing an LLC resonant topology (replacing the traditional PWM topology) combined with wide-bandgap SiC MOSFETs (with a withstand voltage of 120V and a switching frequency of 100-200kHz), this achieves a wide input range of 9-60V while improving conversion efficiency (from the traditional 88% to 92%).

　　Power Density Improvement: Utilizing a planar transformer (thickness ≤ 10mm, 40% smaller than traditional transformers) and synchronous rectification technology (using MOSFETs instead of diodes to reduce conduction losses), the power supply is kept within a footprint of 150×80×40mm (power density ≥ 50W/in³), making it suitable for installation in confined spaces within the vehicle (such as under the dashboard and under the seat). (II) Automotive-Grade Anti-Vibration and Wide-Temperature Technology

　　Anti-Vibration Structure Design: The PCB utilizes thickened FR4 material (2.0mm thick, compared to the traditional 1.6mm) with a 100μm copper foil thickness for enhanced mechanical strength. Components are packaged in surface-mount form to prevent loosening. Key components (such as capacitors and inductors) are underfilled with epoxy potting compound (hardness Shore D 60, thermal conductivity 1.2W/(m・K)) to secure the components and improve heat dissipation. The housing is constructed of aluminum alloy (thermal conductivity 160W/(m・K)) with an anodized surface treatment for enhanced vibration resistance and heat dissipation.

　　Wide-Temperature Component Selection: The core chips (PWM controller and driver chip) are industrial-grade (operating temperature -40~125°C). The output capacitors utilize automotive-grade X7R ceramic capacitors (temperature coefficient ±15%, -55~125°C). The inductor core is constructed of heat-resistant ferrite material (Curie temperature ≥200°C), ensuring low-temperature operation. There is no electrolyte solidification at 40°C and no parameter drift at high temperatures of 85°C.

　　(III) EMC Interference Suppression and Safety Protection

　　EMC Filter Optimization: A common-mode inductor (10mH, saturation current 30A) is connected in series with an X capacitor (0.1μF/250V) and a Y capacitor (1000pF/500V) on the input side to suppress common-mode and differential-mode interference. The PCB layout adopts an "input-power conversion-output" partitioning design, with a single-point connection between the analog ground and the power ground to reduce noise coupling. An RC snubber network (10Ω resistor, 100pF capacitor) is connected in parallel with the switching transistor to suppress switching spike noise.

　　Intelligent Protection Control: A dual-core MCU (microcontroller) monitors input voltage, output current, and heat sink temperature in real time with a 10kHz sampling frequency. Overvoltage, overcurrent, and overtemperature protection is triggered within 10μs. Automotive-grade Schottky diodes (forward current 30A, reverse voltage withstand 100V) are used for reverse polarity protection to prevent circuit burnout in the event of reverse polarity. A "soft start" feature is also included. Function (startup time 500ms), preventing damage to devices caused by the instantaneous surge current during power-up.

　　IV. In-Vehicle Application Demonstration (Scenario-Based Value Verification)

　　Powering Multiple Devices in a Passenger Car: This power supply was used in a 12V passenger car, simultaneously driving a 12V/5A navigation system (60W), a 12V/8A car refrigerator (96W), a 12V/2A dashcam (24W), and a 12V/3A rear entertainment screen (36W), for a total power of 216W (≤ 300W rated power). During vehicle start-stop cycles, the input voltage dropped from 13.5V to 9.2V, but the power supply maintained a stable 12V output (±0.1V fluctuation), with no device power outages. After two hours of continuous driving (engine compartment temperature 75°C), the power supply heatsink temperature reached 68°C, with a conversion efficiency of 91%, and no overheating protection. 24V Commercial Vehicle Communication Power Supply: A 24V logistics truck uses this power supply to power a 24V/10A 4G communication module (240W). Even when driving on bumpy rural roads (10-500Hz vibration, 8g acceleration), the power supply outputs 24V±0.2V, and the communication module maintains connectivity. When started in winter at -35°C, the power supply outputs normally within 3 seconds, allowing the communication module to connect to the network smoothly, avoiding logistics information interruptions that can occur when traditional power supplies fail to start at low temperatures.

　　48V New Energy Light Truck Auxiliary Equipment Power Supply: A 48V new energy light truck uses this power supply to convert 48V input to 24V output, powering a 24V/12A ADAS radar (288W). The input voltage of the light truck rose to 54V during charging, and transiently spiked to 60V during rapid acceleration. The power output remained stable at 24V (with an accuracy of ±0.5%), and the radar did not generate any fault alarms. During continuous operation for 8 hours (at an ambient temperature of 35°C), the power efficiency remained above 90% with no abnormal heating. V. Key Selection Points (Focusing on Automotive Requirements)

　　Input and Output Compatibility Verification:

　　Input voltage: Must cover 9-60V, ensuring compatibility with 12V/24V/48V automotive systems. This prevents narrow input models (e.g., 12-24V) from being unable to cope with startup voltage drops or transient spikes.

　　Power Redundancy: Reserve 20% redundancy based on the total load power (e.g., a 300W power supply for a 250W total load) to mitigate device startup shock (peak power demand).

　　Output Voltage: Prioritize customizable models (e.g., dual 12V/24V outputs) to accommodate automotive devices of varying voltage levels and reduce the number of power supplies required. Vehicle Environmental Endurance Verification:

　　Temperature Range: The operating temperature must be -40°C to 85°C. In northern regions with severe cold, it must be verified that the system can start without delay at -40°C. In southern regions with high temperatures, it must be verified that the system can operate at full load without overheating at 85°C.

　　Vibration Resistance: The system must comply with ISO 16750-3 (10-2000Hz, 10g acceleration) to prevent loose components caused by vibration.

　　Protection Rating: IP65 for engine compartment/underbody installations, IP54 for cab installations, ensuring dust and water resistance. EMC and Safety Compliance:

　　EMC Certification: Must comply with CISPR 25 Class 2/3 (selected based on the sensitivity of the in-vehicle device). Provide a third-party EMC test report to avoid interference with ECUs and radars.

　　Safety Protection: Ensure the five protections of overvoltage, overcurrent, overtemperature, short circuit, and reverse polarity are present. (Missing reverse polarity protection can easily damage the power supply.)

　　Reliability: MTBF ≥ 100,000 hours, service life ≥ 8 years, matching the vehicle's lifecycle to reduce future replacement costs. Installation and Compatibility:

　　Size and Mounting: Select a model ≤180×100×50mm, supporting DIN rail or bolt mounting (adaptable to different vehicle mounting locations);

　　Interface Compatibility: Input and output interfaces utilize automotive-grade terminals (such as AMP terminals), with wire diameters ≥6mm² (input) and ≥4mm² (output 300W) to minimize overheating caused by high current;

　　Diagnostic Features: Prefer models with CAN bus communication, which can upload real-time power supply operating status (voltage, current, and temperature) to the vehicle's instrument panel for easy troubleshooting.

Read recommendations:

120W Desktop Power Adapter

40W US Plug Switching power supply

MKS-1203000EX

12V60W wall adapter Customizde

PD100W Interchangeable Charger with Foldable Plugs