Industry-leading*1 low-loss materials contribute to the improved performance and downsizing of automotive ECUs
Osaka, Japan – Panasonic Corporation announced today that it has commercialized a surface mounted automotive power choke coil  suitable for power circuits in electronic control units (ECUs) installed in vehicles such as gasoline, diesel, and hybrid cars equipped with internal combustion engines, which are under pressure to meet the growing demand for improved fuel efficiency. The product features low loss, high withstand voltage, and high vibration acceleration-resistant characteristics, and will be mass-produced starting in February 2021.
With ever-tightening environmental regulations around the world, emission regulations for cars with internal combustion engines are becoming more stringent. In order to improve emissions performance, it is necessary for such cars to efficiently burn fuel to achieve complete combustion as much as possible. Accordingly, the direct fuel injection method  that directly injects fuel at high pressure into the cylinder has been adopted to facilitate highly efficient fuel combustion. Complete combustion requires fuel to be atomized and finely injected. For that purpose, it is indispensable for the coil used to boost the voltage of the injector drive unit of a direct injection engine to have the low loss and high withstand voltage characteristics in order to shorten its boost voltage recovery time. In addition, more automotive ECUs are being placed in the engine compartment, increasing the integration of mechanical and electronic in-vehicle components . Moreover, this trend has created a need for automotive ECUs that can be installed in high-temperature environments under more severe vibration conditions and support larger currents. Panasonic has independently developed industry-leading low-loss magnetic materials with high withstand voltage to commercialize a surface-mounted automotive power choke coil that achieves the higher performance and downsizing of automotive ECUs.
Panasonic’s new automotive power choke coil has the following features:
1. Halved power loss and doubled high withstand voltage performance*2 compared to conventional products through the use of industry-leading low-loss magnetic materials with high withstand voltage.
- • Power loss: 1.5 W (Panasonic’s conventional product*3: 3 W)
- • High withstand voltage: up to 125 V (Panasonic’s conventional product*4: up to 60 V)
2. The downsizing and the reduced number of coils required to be incorporated into ECUs due to the improved performance contribute to ECU space saving.
- • Size: 12.5 mm2 (Panasonic’s conventional product*3: 14 mm2)
3. The product eliminates the need for anti-vibration reinforcement as part of the mounting process, reducing the use of reinforcing measures with bonding agents (adhesives).
- • High resistance to vibration: up to 30 G
- *1: As a surface-mounted power choke coil for automotive use (with a size of 10 to 12.5 mm2) as of Dec. 21, 2020 (Panasonic data).
- *2: When the coil is driven by a triangular wave current with a peak value of 13 Ao-p, a frequency of 75 kHz, and a duty cycle of 35%.
- *3: Panasonic’s conventional product: 14-mm2 dust core power choke coil for automotive use (PCC-D1413H series).
- *4: Panasonic’s conventional product: 10-mm2 power choke coil for automotive use (PCC-M1054M series).
Boosting DC/DC converter circuits  for gasoline, diesel, and hybrid cars, power circuits in highly functional automotive ECUs, and automotive ECU circuits integrated with mechanical drive components.
1. Halved power loss and doubled high withstand voltage performance compared to conventional products through the use of industry-leading low-loss magnetic materials with high withstand voltage
In accordance with environmental regulations, the internal combustion engines of cars are required to conform to further CO2 reduction requirements and emission controls, which has led to the introduction of fuel injection based on the direct injection method and the lean burn control  of fuel.
Power choke coils incorporated into automotive ECUs are used in boosting circuits; therefore, high withstand voltage characteristics are required in addition to lower power loss and greater downsizing features. Conventional products faced issues of unsatisfactory power loss and withstand voltage characteristics and were unable to allow large currents to flow. Panasonic has developed new low-loss magnetic materials capable of handling large currents with a high withstand voltage based on metal composite materials  using its in-house-developed metallic magnetic materials to commercialize a power choke coil with halved power loss and doubled high withstand voltage performance compared to conventional products. These features will contribute to the improved performance and downsizing of automotive ECUs.
2. Downsizing and reduced number of coils required to be incorporated into ECUs contribute to ECU space saving
With the rapidly expanding computerization of cars, ECUs are being incorporated more frequently in the engine compartment and the engine itself, which requires the downsizing of ECUs. Accordingly, Panasonic has developed a high performance power choke coil using its in-house-developed magnetic materials and winding technology for forming coils with high accuracy. The size of the coil was reduced to 12.5 mm2, smaller than a comparable conventional product (14 mm2), and the volume was reduced by 40% compared to the company’s conventional power choke coil used for direct fuel injection. Additionally, the reduced number of coils required to be incorporated into ECUs due to the improved performance contributes to ECU space saving.
3. The product removes the need for the anti-vibration reinforcement as part of the mounting process, allowing streamlining of the process
In conventional automotive ECU board mounting processes, reinforcement measures to fix components with bonding agents (adhesives) were necessary for ensuring the high vibration acceleration-resistant performance. This product employs Panasonic’s original coil winding and forming technologies, which reduce the height of the terminal’s pull-out position down to half compared to the company’s conventional products. Positioning closer to the mounting circuit board have achieved excellent vibration resistant performance. This removes the need for anti-vibration reinforcement and contributes to the streamlining of the mounting process.
< Structure comparison >
W × D × H (mm)
|PCC-M1280MS||14.0 × 12.5 × 8.0||40 μH||41.0 mΩ||5.9 A||125 V|
- *1: Measured at 100 kHz
- *2: Current value that causes a temperature rise of 40°C
Panasonic will expand the inductance range of the product and add smaller models to enhance the product lineup to respond to market needs in the future.
-  Power choke coil
This is an electronic component used in DC/DC converter circuits, etc., that serves as a filter for accumulating energy and removing noise.
-  Direct fuel injection method
Method of directly injecting gasoline into cylinders at high pressure.
-  Integration of mechanical and electronic in-vehicle components
This refers to the integration of mechanical drive components and automotive ECUs. Mechanical drive components and automotive ECUs used to be installed separately, but were interconnected via cables. Demand for high-precision control, higher degree of freedom in component layout, reduction in the number of cables, etc. has led to the adoption of an integrated configuration of mechanical and electrical components.
-  DC/DC converter circuit
This is a circuit that converts direct current from one voltage to another.
-  Lean burn control
Combustion of fuel with a smaller injected amount than the theoretical air fuel ratio.
-  Metal composite material
This refers to a magnetic material made by the compression molding of metallic magnetic
material-based (iron group) powder insulated with resin.
-  Inductance
This is an indicator of coil performance. Passing a changing current through a coil will generate a voltage that passes current in a direction that hinders the current change.
The rate of the generated voltage is referred to as inductance.
-  DC resistance
DC resistance is a resistance component of a winding (copper wire). The lower the DC resistance, the smaller the power loss, thereby improving the power supply efficiency.