Buck Converter for E-Scooters – 4.5V to 95V input – 5V output

This high-voltage buck converter is specifically designed for e-scooter and e-bike control power supply applications, but its versatility also makes it suitable for use in solar energy systems, automotive systems, and industrial power supplies. This converter utilizes the MPS9486 chip, a 4.5V-to-95V-input, 1A-output step-down converter that provides efficient power conversion.

The MP9486 chip employs a hysteresis voltage control method, which enables fast response to line or load transients, ensuring stable output voltage. Additionally, it integrates a high-side high-voltage power MOSFET with a current limit exceeding 1.7A, providing reliable and efficient power delivery.

The board is pre-configured for a 5V step-down application, making it an ideal solution for a wide range of applications that require a stable and efficient 5V power supply. With its robust design and high-performance capabilities, this high-voltage buck converter is an excellent choice for various power supply needs.

The output voltage of this board is set to 5V. With an input ranging from 8V (lower input may cause insufficient BST voltage) to 95V, this board can provide a load up to 1A.

Features

• Input Supply 8V-To-95V Wide input Range
• Output 5V DC
• Output Current Up to 1A
• Hysteretic Control: Simple Compensation
• Frequency Up to 1Mhz
• Hiccup mode Short Circuit Protection
• Thermal Shutdown
• PCB Dimensions 23.34 x 22.86 mm

Under-Voltage Lockout (UVLO)

Under-voltage lockout (UVLO) is implemented to protect the chip from operating at an insufficient supply voltage. The UVLO rising threshold is about 4V, while its falling threshold is a consistent 3.6V.

Thermal Shutdown

Thermal shutdown is implemented to prevent the chip from operating at exceedingly high temperatures. When the silicon die temperature is higher than its upper threshold, the entire chip shuts down. When the temperature is lower than its lower threshold, the chip is enabled again.

Output Short Protection

The output voltage is well-regulated when VFB is around 200mV. If the output is pulled low in over-current protection (OCP) or is shorted to GND directly, VFB is low, even though the power MOSFET is turned on. The MP9486 regards the low VFB as a failure. The power MOSFET shuts off if the failure time is longer than 10µs.  The MP9486 attempts operation again after a delay of about 300µs.  The power MOSFET current is also accurately sensed via a current sense MOSFET. If the current is over the current limit, the IC is shut down. This offers extra protection under output short conditions

Hysteresis Current Control with Adaptive

Threshold Adjustment the MP9486 operates in a hysteretic voltage control mode to regulate the output voltage. FB is connected to the tap of a resistor divider, which determines the output voltage. The power MOSFET is turned on when the FB voltage (VFB) drops to 185mV and remains on until VFB rises to 215mV. The power MOSFET is turned off when VFB rises to 215mV and remains off until VFB falls to 185mV. The two thresholds of 215mV and 185mV are adjusted adaptively to compensate for all the circuit delays, so the output voltage is regulated with an average 200mV value at FB.

Connections

• CN1: Pin 1 = 8V To 95V DC Input, Pin 2 = GND, Pin 3 = 5V DC Output
• D2: Power LED (Output)

Schematic

Parts List

Connections

Typical Application

Load Regulation

Line Regulation

Efficiency

Block Diagram

Gerber View

Photos

Video

MPS9486 Datasheet