High-voltage DC/DC converters are widely used in industrial electronics, automotive systems, telecommunications, energy storage, battery-powered equipment and other applications where the input supply can be significantly higher than the low-voltage rails required by processors, sensors and control electronics.
Design engineers traditionally source these devices from established analog semiconductor manufacturers. However, a growing number of Chinese semiconductor companies now offer buck converters covering input-voltage ranges from approximately 40V through 100V, providing additional options for new designs, second sourcing and cost optimization.
This article looks at several manufacturers and example devices in the 40V, 60V, 80V and 100V classes, with particular attention to products that may be relevant to European industrial, energy, communications and automotive electronics designs.
The devices listed below should be considered potential design alternatives rather than automatic replacements. Electrical characteristics, package, pinout, protection functions, qualification and application requirements must always be verified against the latest manufacturer documentation.
Many electronic systems operate from nominal supply rails that are substantially higher than the 1V to 12V rails required by digital and analog circuitry.
Typical examples include:
→ 12V and 24V industrial control systems
→ 24V and 48V communications equipment
→ Motor-control and servo systems
→ Battery-management systems
→ E-bikes, scooters and light electric vehicles
→ Energy-storage systems
→ Solar and inverter electronics
→ Automotive electronic modules
→ Industrial instrumentation and automation
The required converter voltage rating should not be selected only from the nominal bus voltage. Supply tolerance, switching transients, load dump, inductive effects and the applicable system specification may require additional voltage margin.
The following devices illustrate some of the high-voltage buck-converter products available from Chinese power-management semiconductor suppliers.
| Manufacturer | Example Device | Input Voltage | Output Current | Type / Key Feature | Switching Frequency |
|---|---|---|---|---|---|
| MST | MST8432 | Up to 40V | 3.5A | Synchronous CC/CV buck | Check datasheet |
| SCT | SCT2430Q Series | Up to 40V | 3.5A | Synchronous buck | 100kHz–2.2MHz |
| SCT | SCT2650B | 4.3V–60V | 5A | High-current buck converter | 100kHz–2.2MHz |
| SGMICRO | SGM61630D | 4.3V–60V | 3A | Wide-input buck converter | 200kHz–2.5MHz |
| JoulWatt | JW5121 | 4.5V–60V | 2A | Asynchronous buck converter | 100kHz–2MHz |
| SCT | SCT2820 / SCT2821 Series | Up to 80V | Up to 2A | High-voltage buck family | Up to approximately 2.2MHz depending on device |
| SCT | SCT2A23 | 4.5V–100V | 1.2A | Synchronous buck / Iso-buck capable | 300kHz |
| MST | MST8A50QA | Up to 100V | 5A | Synchronous step-down converter | Check datasheet |
| MST | MST8A100KE | Up to 100V | 10A | High-current synchronous step-down converter | Check datasheet |
| Silergy | SY8510ADC | 4.5V–100V | 0.3A | Asynchronous step-down regulator | 200kHz |
The table is intended as a starting point for device research. Output current alone does not determine whether two converters are interchangeable, and some products may target substantially different applications despite having similar voltage ratings.
The 36V to 42V class is commonly used in designs that need more headroom than conventional 24V or 30V regulators while still prioritizing compact size, high switching frequency and relatively high output current.
Applications can include industrial electronics, automotive accessories, motor-control electronics, appliances and systems powered from nominal 12V or 24V sources.
Milestone Semiconductor lists the MST8432 as a 40V, 3.5A synchronous buck DC/DC converter supporting constant-current and constant-voltage operation.
This type of device can be particularly relevant where both voltage and current regulation are useful, including charging and battery-related applications.
Silicon Content Technology offers a broad 40V-class buck-converter family. Devices in this range include converters supporting output currents from relatively low-power auxiliary rails through multi-amp industrial and automotive applications.
For example, the SCT2430Q family operates from approximately 3.8V to 40V and supports up to 3.5A output current with adjustable switching frequency.
The 60V class is especially interesting for European industrial electronics because it can address many systems based around 24V and 48V power architectures.
Applications include industrial control, PLC systems, PoE equipment, communications hardware, motor drives, battery systems and distributed power architectures.
The SCT2650B supports input voltages up to 60V and output currents up to 5A. The device provides an adjustable switching-frequency range extending into the MHz region, allowing designers to balance efficiency, passive-component size and EMI requirements.
SCT positions its 60V buck-converter products for applications including 12V, 24V and 48V industrial and telecom power systems, industrial automation, motor control and vehicle accessories.
The SGM61630D is a 4.3V to 60V buck regulator capable of delivering 3A continuous output current.
It offers adjustable switching frequency from 200kHz to 2.5MHz and features a typical operating quiescent current of 50µA. Protection functions include thermal protection, current limiting and over-voltage protection.
The device targets applications including industrial power supplies, telecom and datacom systems and other wide-input-voltage power-conversion designs.
The JoulWatt JW5121 is a 60V-class asynchronous step-down converter supporting up to 2A output current.
Its wide switching-frequency adjustment range provides flexibility when balancing conversion efficiency, EMI behavior and external component size.
Moving from 60V to approximately 80V can provide additional design margin for higher-voltage battery systems and industrial power rails where a conventional 60V device may not provide sufficient voltage headroom.
Silicon Content Technology has established dedicated 80V buck-converter product families. Examples include the SCT2820 and SCT2821 series, which combine 80V input capability with output-current ratings in the 1A to 2A range.
Because product availability and production status can change, engineers evaluating 80V devices should confirm the current release status, samples and production schedule directly against the latest manufacturer information before beginning a design.
The 100V class is particularly interesting for higher-voltage industrial systems, battery applications, e-bikes, telecommunications equipment and designs where substantial transient margin is required.
Several Chinese power-management semiconductor companies now offer integrated 100V buck-converter devices.
The SCT2A23 is a synchronous buck converter operating from a 4.5V to 100V input and supporting up to 1.2A continuous output current.
The device integrates both high-side and low-side MOSFETs and operates at a fixed 300kHz switching frequency.
Selectable operating modes allow designers to optimize light-load efficiency, avoid audible-frequency operation or use forced PWM operation. The device can also support an Iso-buck topology where an isolated auxiliary supply is required.
Typical target applications include battery-management systems, e-bikes, scooters and tracking equipment.
Milestone Semiconductor also offers unusually high-current 100V synchronous step-down converters.
→ MST8A50QA – 100V input, 5A synchronous step-down converter
→ MST8A100KE – 100V input, 10A synchronous step-down converter
MST highlights these products within its e-bike power-conversion solutions, making them potentially interesting for higher-voltage battery and light-electric-vehicle applications.
Silergy’s SY8510ADC provides another example of a 100V-class converter, but at the opposite end of the current range.
The device operates from 4.5V to 100V and supports approximately 0.3A output current with a 200kHz switching frequency.
This type of device can be appropriate for low-power auxiliary rails where high input-voltage capability is more important than high output current.
High-voltage buck converters can appear in a wide range of electronic products.
→ Industrial automation – converting 24V or 48V rails to logic, MCU, sensor and communication voltages
→ Motor control – generating auxiliary rails for gate drivers, control electronics and interfaces
→ Energy storage – powering BMS, monitoring and communication electronics
→ Solar and inverter systems – auxiliary power conversion and control-board supplies
→ Telecommunications – conversion from 48V-class system power
→ E-bikes and scooters – converting battery voltage to lower-voltage electronics
→ Automotive electronics – auxiliary power conversion where appropriate automotive qualification is available
→ Industrial IoT – powering processors, radios, sensors and interfaces from higher-voltage field supplies
The input-voltage rating is only one parameter when evaluating an alternative DC/DC converter.
Engineers should compare:
→ Recommended input-voltage range
→ Absolute maximum ratings
→ Continuous output current
→ Current-limit behavior
→ Output-voltage range
→ Switching frequency
→ Minimum on-time
→ Control architecture
→ Synchronous versus asynchronous operation
→ MOSFET RDS(on)
→ Quiescent current
→ Light-load operating mode
→ Efficiency
→ EMI characteristics
→ Thermal performance
→ Package
→ Pin configuration
→ Protection functions
→ Operating-temperature range
→ Qualification requirements
→ Product lifecycle and long-term availability
Another important consideration is whether the converter integrates both switching MOSFETs or requires an external rectifying device.
A synchronous buck converter replaces the conventional rectifier diode with an actively controlled MOSFET. This can improve efficiency, particularly when output current is relatively high or the output voltage is low.
Asynchronous devices can offer a simpler architecture and may remain attractive for lower-current applications where cost, simplicity or particular operating conditions are more important than maximum conversion efficiency.
Two DC/DC converter ICs can have the same maximum input voltage and output-current rating while requiring completely different PCB designs.
Differences can include:
→ Pinout
→ Package dimensions
→ Feedback reference voltage
→ Inductor requirements
→ Compensation network
→ Switching frequency
→ External diode requirements
→ Enable thresholds
→ Power-good functionality
→ Thermal-pad construction
For this reason, the term “alternative” should normally mean a device worth evaluating for the same design requirement rather than automatically implying pin-to-pin compatibility.
If you are currently using a high-voltage DC/DC converter and would like to identify possible alternative devices, send AnySilicon your existing part number and application requirements.
Useful information includes:
→ Current manufacturer
→ Current part number
→ Minimum and maximum input voltage
→ Required output voltage
→ Required output current
→ Application
→ Operating-temperature requirement
→ Automotive or industrial qualification requirement
→ Expected annual volume
→ Target production date
Submit your existing DC/DC converter part number to AnySilicon to identify potential alternative devices. Contact us here.
The devices discussed in this article are examples of products available in the high-voltage DC/DC converter market. Inclusion does not indicate that AnySilicon distributes, represents or endorses a particular manufacturer.
Product specifications, availability and qualification status can change. Engineers should always consult the latest manufacturer datasheet and qualification documentation before selecting a device.
A device should not be considered pin-compatible, functionally equivalent or suitable for a safety-critical application unless the complete design has been independently reviewed and validated against the applicable requirements.