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작성일 2025-08-27 작성자 최고관리자

EV Off-Board Charging Station

Off-board Charger for EV

An off-board charger is an external charging device
that receives AC power and converts it to DC power internally
to directly charge electric vehicle batteries.

That is, unlike the on-board charger (OBC) mounted in the vehicle,
the charger itself has AC/DC conversion capability and is installed separately,
primarily used for fast charging (DC charging) methods.

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Off-Board Charger

Off-Board Charger

Off-board chargers require fast charging technology
to enhance EV convenience.
This requires high-frequency switching while also demanding high efficiency.
We contribute to fast charging and high efficiency with a lineup
of various power semiconductors centered on SiC devices.

AP SEMI has launched Super Junction MOSFETs with significantly improved TRR speed
through electron irradiation, offering a diverse lineup of high-power MOSFET
and RECTIFIER products suitable for fast switching speed drives.

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01

DCDC Converter Topology
of Quick charger for EV

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02

High Power Transistor
High Power TR

In LED converters (SMPS), power MOSFETs are used as power TRs
that convert input voltage to desired DC voltage and play a switching role
in supplying stable current and voltage to LEDs.
Since MOSFET characteristics significantly affect converter efficiency
and noise reduction performance, MOSFET characteristics must be
fully considered when designing LED lighting.

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MOSFET Application 01

High-Efficiency Power Control

Since converter efficiency varies depending on MOSFET characteristics (e.g., on-resistance, switching speed),
select MOSFETs with high efficiency.

MOSFET Application 02

Heat Generation

OBC converters with high current generate heat, so consider appropriate heat dissipation measures
and select MOSFETs with low heat generation and good durability. Since heat dissipation capability
varies greatly depending on package type, check PD (Power Dissipation) before selection.

MOSFET Application 03

Voltage and Current

Select MOSFETs with sufficient specifications to handle
the input voltage and output current required for LED converters.

03

MOSFET Types and Characteristics

  • 01

    Planar MOSFET

    • Advantages

    Simple structure, easy to manufacture with low cost, and has low noise characteristics
    for good EMI performance.

    • Disadvantages

    Large device ON resistance (RDS(on)), slow switching speed, increased device size
    at the same voltage rating, and lower efficiency.

  • 02

    Super Junction MOSFET

    • Advantages

    ON resistance (RDS(on)) and gate charge (Qg) are significantly lower than Planar MOSFETs,
    improving efficiency with high-speed switching performance.

    • Disadvantages

    Larger PN Junction area than Planar type results in higher reverse recovery current (irr)
    during ON-OFF transitions, tends to have higher noise during high-speed switching, and is
    more expensive due to highly integrated structure implementation.

  • 03

    SiC MOSFET (Silicon Carbide)

    • Advantages

    Has wider bandgap than Si, delivering excellent performance even at high temperatures and voltages,
    providing high efficiency with low conduction loss and high switching speed. Particularly suitable
    for power conversion devices such as electric vehicle inverters and OBC (onboard chargers).

    • Disadvantages

    Requires high-temperature processes above 2000℃, which is time-consuming and significantly
    increases costs. High price and reliability issues (SiO2-SiC interface problems) result in low yields,
    which can be a supply issue during commercialization.

  • 04

    GaN MOSFET (Gallium Nitride)

    • Advantages

    Higher electron mobility than SiC enables very fast switching speeds, low conduction
    resistance minimizes power loss and increases power density, reducing size and weight of compact
    power supply devices while improving efficiency.

    • Disadvantages

    Higher conductivity than SiC can limit possible power density, and yield and reliability
    issues still exist.

MOSFET Lineup

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04

Rectifier DiodeRectifier Diode

Since the forward voltage of rectifier diodes in power converters is directly related to power loss,
high-efficiency power diodes must be used to increase efficiency.
By using diodes with short reverse recovery time
(TRR: Reverse Recovery Time)
to reduce switching losses, efficiency is increased and losses are minimized.

Rectifier Diode Types and Characteristics
Standard Rectifier

Rectifier Diode with slow reverse recovery characteristics with TRR of 2-20 micro Sec.,
mainly used in primary rectification of adapters or power supplies or low-frequency circuits such as toys

Fast Recovery Rectifier

Rectifier Diode with TRR of 100~750 nano Sec., used in high-frequency (20~50Khz) circuits

Ultra Fast Recovery Rectifier

Rectifier Diode with TRR of 35~75 nano Sec., generates less heat than Fast Recovery Rectifier,
mainly used in high-voltage (400V~1000V), high-frequency (50Khz or higher) circuits

Ultra High Efficient Rectifier

High-speed rectifier Diode with TRR of 10~35 nano Sec., low resistance ($V_F$) reduces heat generation.
Used in low-voltage (up to 200~600V), high-frequency (50~200Khz) circuits

Schottky Barrier Rectifier

Very low internal resistance and fast operation speed, but low operating voltage and high leakage current.
Mainly used in high-frequency, high-current, low-voltage rectification

Ultra Low $V_F$ Schottky Rectifier

Schottky rectifier that uses trench process compared to general Schottky to significantly reduce forward voltage

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05

Photocoupler
Photo Coupler, Optocoupler, Isolator

A photocoupler is a device that transmits signals between the input and output circuits
in an electrically isolated state by activating the phototransistor (light-receiving section)
with light emitted when the internal LED turns on. When the electrical signal of the input circuit
flows current to the LED to generate light, this light passes through the phototransistor
to flow current to the output circuit, and through this,
signal transmission between the two circuits is achieved.

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06

Shunt Regulator
Shunt Regulator

A shunt regulator is a device that regulates voltage to maintain stable output
despite input voltage fluctuations or load changes.
'Shunt' refers to a method of regulating voltage by connecting in parallel
to the load that conducts current, operating on the same principle as a shunt
to supply stabilized power at a specific voltage level.

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