B3603 3A 6-40V In 0-36V Out DC-DC Digital Control CV/CC Step-Down Buck Converter Module

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  • Regular price $18.39
  • 6 available

The B3603 DC-DC Digital Control Step-down Module is a digitally controlled constant voltage/constant current step-down (buck) converter module with a 4-character LED display. Its high speed micro controller provides precise control and display of voltage and current (actual and setpoint), output power, and capacity (power over time).  Indicator LEDs display Output On, Constant Voltage Mode and Constant Current Mode. 

In its basic operating mode, the output voltage and current setpoints are entered using the Set, Arrow Up and Arrow Down buttons. The OK button saves the values and enables the output. While operating in Constant Voltage Mode, pressing the up and Down arrows increases or decreases the output voltage, In Constant Current Mode, the arrows control the output current. A short press of the "OK" button switches display parameters between voltage, current, power and capacity. A long press for 3 seconds will change the output to automatically scroll through the parameters, another long press reverts to the previous mode. Pressing the Set button disables the output. 

The B3603 also includes advanced operating parameters that can be programmed through the digital interface. These include: 

Function 0: Changes power-on default status from off to enabled (i.e. if the function is disabled, when the module is powered on, the output stays off until the OK button is pressed, if the function is enabled, when powered on, the module will immediately enable the output.

Function 1: Store and retrieve up to 10 sets of operating parameters.

Function 2: When enabled, the display will automatically scroll through the operating parameters voltage, current, power, and capacity.


  • Versatile and economical constant voltage / constant current lab or benchtop power converter.
  • Constant voltage step-down converter to reduce an input voltage, for example, it could step a 12V car battery down to 5V for USB-powered devices such as cell phones or Arduino microcontrollers. 
  • Constant current power supply for driving LEDs, Laser Diodes, battery charging, or to regulate the output of solar panels or wind turbines to charge energy storage batteries. This is an inexpensive way to charge those 4.30v and 4.35v cells, as well as LiFePo and many other cells that require different termination voltages. It is also a good way to charge smaller cells since you can almost infinitely adjust the charging current and output voltage.


  • Digital display and control, convenient and easy to use
  • Constant voltage and constant current modes
  • OUT, CV and CC indicator LEDs
  • Adjust output voltage and current value accurately
  • Displays actual and set voltage and current, power, and capacity (cumulative power over time)
  • Can be set to power on at preset voltage level or in a disabled mode (requires a button push to enable)
  • 10 groups of storage locations to store and retrieve preset operating parameters


  • Input voltage: 6 - 40V
  • Output voltage: 0 - 36V
  • Output current: 0 - 3A
  • Voltage regulation/display resolution: 0.01 V
  • Current regulation/display resolution: 0.001 A
  • Minimum display resolution of power: 0.001 W
  • Minimum display resolution of capacity: 0.001 AH
  • Conversion efficiency: up to 92%
  • Output ripple: ≦50 mV
  • Working temperature: - 40°C ~ + 85 °C
  • Working frequency: 150 KHz
  • Short circuit protection: Constant current
  • Input reverse connect protection: No, if necessary please install diode
  • Connection mode: Terminals
  • Size (mm):66 (long)* 50 (wide) * 21 (high)
  • Weight: 43 g

Package includes:

1x B3603 3A 6-40V In DC-DC Digital Control CV/CC Step-Down Buck Converter Module
Printed installation and operation instructions



Video review of the B3603 by Julian Ilett on Youtube: