Tech Library
Products & Technologies
[ ]
Product Overview
The PLE Series power inductor is a high-efficiency, low-leakage flux, ultra-compact power inductor that excels during operation with small batteries, such as those used in wearable devices.
Using our proprietary structural design and newly developed materials, it achieves a wide range of inductance values through a thin-film process.
This chapter explains the structure and characteristics and provides other useful information including applications. 

Product Overview

The overview of the PLE Series is presented in Figure 1.

Figure 1: Product Overview
Series PLE***B PLE***D
Product Overview - Ultra-compact power inductor ideal for small wearable devices such as TWS (True Wireless Headphones)
- Broad range of inductance values achieved through high-precision thin-film lamination technology
- Adoption of high permeability and low loss metallic magnetic materials improves power efficiency under light load conditions, which significantly impacts battery life
- Structure that suppresses leakage flux, minimizing noise impact on the board and surrounding components even in high-density mounting situations
Features - Wide range of inductance values in an ultra-compact form
- Low loss, high efficiency
- Low leakage flux
- Operating temperature range: -40°C to 125°C
- Vertical coil winding structure
- Leakage flux is in the horizontal direction
- The direction of the magnetic flux does not change even when the mounting direction is changed
- Horizontal coil winding structure
- Leakage flux is in the vertical direction
- Polarity mark present
- Low profile
- Compatible with high-density mounting

Wearable products (TWS, smartwatches, hearing aids)
Small power modules
Communication modules (GNSS, Bluetooth, etc.)

Product Structure

The structure of the PLE series is shown in Figure 2.
The PLE Series leverages thin-film technology that is based on thin-film HDD heads, resulting in an ultra-compact inductor. This, when combined with high-precision lamination technology, enables the PLE Series to offer a wide spectrum of inductance values.
A new high permeability and low loss metallic magnetic material has been developed, resulting in low loss and high efficiency.
The product lineup includes two types of structures with different shapes and coil winding directions.

Figure 2: Product Structure

The thin-film process used in the PLE series has the following features, making it ideal for ultra-compact power inductors:
- It enables high-precision lamination, allowing for reduced variability.
- It allows for the realization of 2 or more windings per layer, providing a wide range of inductance values in the product lineup.

Figure 3 presents a comparison between the thin-film process and the conventional winding and lamination methods, which are representative techniques for inductor construction.

Figure 3: Characteristics of Thin-Film Process

Product Features

The PLE series employs a fully shielded structure to suppress magnetic flux leakage, thereby reducing the impact of noise in high-density mounting environments.
The direction of the magnetic flux generated by the coil varies depending on the series, facilitating optimal selection tailored to specific applications. This capability enables a reduction in noise impact on the board's GND surface or minimizes noise interference with surrounding components.

Figure 4: Product Features
Series PLE***B PLE***D
Direction of Magnetic Flux Leakage

Parallel to the board

Perpendicular to the board

Wearable devices powered by small batteries require low power consumption, so Pulse Frequency Modulation (PFM) is used as the power supply drive method.
PFM has the advantage of lower power consumption due to lower DC bias current compared to Pulse Width Modulation (PWM), but has higher AC bias current. (Figure 5)
Therefore, the ACR characteristic becomes important, and by using Hi-Q, low-ACR inductors, it is possible to achieve high power supply efficiency. (Figure 6)

Figure 5: Comparison of PFM and PWM

The PLE series, employing low-loss materials, achieves lower ACR. Consequently, it delivers higher power efficiency compared to larger-sized ferrite inductors.

Figure 6: Comparison of Power Efficiency between the PLE Series and Ferrite Inductors



The application examples of the PLE series are shown in the blue frame in Figure 7.
Due to its ultra-compact form factor, it is ideal for devices requiring high-density mounting such as TWS and communication modules.
It contributes to smaller and lighter products and higher efficiency of power circuits.

Figure 7: Applications


Product List

Click on the links below to view detailed information on the PLE series and purchase samples.
We are committed to expanding our lineup further to accommodate our customers’ diverse inductor needs.

Figure 8: Product List
  • Commercial Grade
Series Application L x W
Height (max.) Inductance
DC Resistance
(mΩ max)
Rated Current
1.0x0.6mm 0.8mm 1.0 265 0.8
2.2 650 0.5
4.7 1080 0.3
1.0x0.8mm 0.55mm 0.47 120 0.7
1.0 300 0.6
2.2 600 0.4
3.3 1200 0.25

What are power inductors?

Power inductors are inductors used for power supply circuit such as DC-DC converters. They are also called power coils or power choke coil. One of the inductors' characteristics is that they store energy by self-induction function. Chopper type DC-DC converters use inductors having such characteristics with switching devices for voltage conversion (see Figure 9).
Depending on the processing method, inductors can be classified into multilayer type, thin-film type, and wire-wound type. Since wire-wound type permits large current to flow, most of the power inductors are wire-wound type. Various wound-type power inductor products with ferrite or soft magnetic metal core are offered. Recently, the multilayer type and thin-film type, with which reduction of size and thickness can be achieved, are being improved to allow for larger current.

Figure 9: DC-DC converter (chopper type / step-down type) and inductor

The voltage is dropped to a desired level in accordance with the duty ratio (the ratio that indicates how long the switch is ON during the switching cycle) setting.

Switching repeated