DC-DC Power Conversion

36 V → 12 V / 5 V Buck Converter

Synchronous step-down DC-DC converter providing regulated 12 V and 5 V outputs from a 36 V eBike or EV bus — engineered for AuMi mobility platforms and embedded control systems.

36 V
Input Voltage
12 V / 5 V
Dual Outputs
≥ 93%
Peak Efficiency
±1%
Output Regulation
10 A
12 V Max Current
3 A
5 V Max Current

Product Overview

The AuMi DC-DC Buck Converter is a dual-output synchronous step-down module designed to power the 12 V vehicle auxiliary bus (lights, horn, relays) and the 5 V logic/USB bus (MCU, sensors, displays) from a 36 V lithium or lead-acid battery pack used in eBikes and light electric vehicles. Both conversion stages use dedicated synchronous buck controllers to achieve high efficiency across the full load range.

12 V Output

Auxiliary Vehicle Bus

Powers lighting systems, relay coils, horn, cooling fans, and general 12 V vehicle loads. Provides up to 10 A (120 W) continuous with built-in over-current fold-back protection.

5 V Output

Logic / USB Power Rail

Supplies microcontrollers, CAN transceivers, sensor modules, display units, and USB charging ports. Provides up to 3 A (15 W) with low-noise LDO post-regulation option for sensitive analog circuits.

36 V Battery EMI Filter Buck #1 36V → 12V 10 A / 120 W Buck #2 36V → 5V 3 A / 15 W 12 V Out Lights, Relays, Fan 5 V Out MCU, Sensors, USB

Block diagram — AuMi 36 V Dual Buck Converter

Key Features

Built for the voltage regulation demands of eBike, EV auxiliary, and embedded control environments.

Synchronous Buck Topology

Low RDS(on) synchronous rectification for high efficiency across the full 0 – 100% load range.

Dual Independent Outputs

12 V and 5 V rails operate independently with separate controllers — a fault on one rail does not affect the other.

Wide Input Range

Accepts 30–42 V input covering the full state-of-charge range of a 10S lithium (36 V nominal) battery pack.

Protections

OCP, OVP, thermal shutdown, and soft-start on both output rails for system safety during startup transients.

Low EMI Design

Input LC EMI filter and PCB layout optimised for AuMi's eBike MCU environment to avoid interference with CAN and Hall sensor lines.

Compact Thermal Design

Exposed-pad power packages on small PCB with optional aluminium baseplate for heatsinking — suitable for enclosed enclosures.

Technical Specifications

12 V Output Stage
Input Voltage30 – 42 V DC
Output Voltage12.0 V ± 1%
Max Output Current10 A
Max Output Power120 W
Ripple (typ.)< 50 mV p-p
Peak Efficiency≥ 93%
Switching Frequency200 – 400 kHz
5 V Output Stage
Input Voltage30 – 42 V DC
Output Voltage5.0 V ± 1%
Max Output Current3 A
Max Output Power15 W
Ripple (typ.)< 20 mV p-p
Peak Efficiency≥ 90%
Switching Frequency300 – 500 kHz

Applications

eBike Auxiliary Power

Powers lights, display, horn, and USB charger from the 36 V traction battery on AuMi Radiance eBike platform.

Robotics & Embedded

Stable 5 V rail for STM32 MCU, CAN transceivers, Hall sensors, and Bluetooth modules in mobile robots.

Light EV Control Units

Auxiliary power supply for control electronics in electric scooters, cargo bikes, and small electric vehicles.

Solar Energy Systems

Step-down from 36 V panel bus to control electronics in MPPT charge controllers and battery management systems.

Need a Custom DC-DC Converter?

AuMi engineers design custom voltage rails and converter modules for OEM and industrial applications.

Contact Us