HOLTEK introduces smart battery charger solution in the Indian EV market

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The Indian electric vehicle market has shown tremendous growth in the past few years, a trend which is expected to witness exponential growth in the future. The driving factors for the growth of the EV market are the government incentives and subsidies for EV infrastructure developments. Also, increasing awareness regarding the environmental impact due to emissions from automotive vehicles and increasing fuel prices strengthens market growth. Electric vehicles are considered environmental friendly alternatives for transportation and are very likely to replace conventional vehicles in the future.

According to a latest report, EV sales in India continue to grow impressively with sales in December 2021 reaching around 51K units, with a month-on-month increase of 21% and a year-on-year increase of a massive 240%. In 2022, sales are expected to reach a figure of 500K units.

The EV market can be placed into several segments such as vehicle type, vehicle class, top speed, region, etc. The vehicle type segment gives a clear distinction of electric vehicles available for consumers. It includes passenger cars, two-wheel vehicles and commercial vehicles. In terms of volume, the two-wheel segment followed by passenger cars are expected to dominate the market. However, a few factors may hamper the growth of the EV market such as a lack of EV chargers, charging infrastructure, high manufacturing cost, km range per charge, service, etc.


HOLTEK is contributing to the growth of the EV market by addressing the EV charger problem with the latest HT45F5Q-xx series of ASSP microcontrollers (MCUs). HOLTEK is providing a smart EV charger solution to efficiently charge batteries to ensure their long life. These ASSP MCUs have the part numbers: HT45F5Q-1, HT45F5Q-2, HT45F5Q-2A and HT45F5Q-3.


The hardware section in the HOLTEK's EV charger solution includes MCUs, reference designs (schematics, Gerber files, etc.) and calibration tools.

When compared with traditional MCU solutions, HOLTEK's ASSP MCUs include an integrated battery charger module which has two sets of OPAs and DACs for voltage and current control. It also includes an OPA to amplify the charging current signal from a current sensing resistor. Other MCU features include an EEPROM, CRC checking and various serial interfaces.

Currently, HOLTEK is offering three EV charger reference designs suitable for the Indian market which can help users with their rapid product development. The specifications are 48V/2A (150W), 24V/4A (150W) both with flyback topology and 48V/12A (650W) with dual-switch forward converter topology. A general block diagram of an EV charger reference design is shown below.

The EV battery charger block diagram of HT45F5Q-xx MCU

The EV battery charger block diagram of HT45F5Q-xx MCU

This suggested smart charging system can support both lithium-ion and lead-acid battery types and includes features such as programmable charging voltage and current, over-temperature, reverse polarity and short circuit protection, LED charging status indicators, etc.

Calibration tool design details are also available for reference allowing users to develop their own EV charger calibration hardware.


HOLTEK has also released a battary charger development workshop for firmware development. This software tool provides a GUI for users to generate firmware in a user-friendly manner. Users can set the charging voltage, current, and other parameters to generate firmware using a standard charging process. Later, the workshop-generated firmware can be modified to include user-defined code.

The HT45F5Q-xx series charger volume production calibration platform is also available to help with the calibration process. A charging voltage and current accuracy of up to ±1% after calibration can be achieved here.

The use of these software tools can greatly shorten the development period and improve the production efficiency.


The integrated battery charger module in the HT45F5Q-xx MCUs eliminates the need for external components such as DACs and OPAs which reduces the design complexity, resulting in smaller PCB areas and lower BOM costs.

HOLTEK also provides complete technical resources such as block diagrams, application circuits, PCB files, source code, etc., to help users to develop their EV charger products.

The availability of technical resources and workshops significantly simplifies the overall development process and helps with rapid product development which reduces the product time-to-market. To learn more about HOLTEK EV charger solutions, please contact your HOLTEK sales representative or email