Mini DC-DC buck converter with fixed or variable output

These amazing little DC-DC converters feature a wide input voltage of 4.5-24V and the output voltage can be set to one of six fixed voltages, or fully variable, just by bridging the relevant solder pads on the back of the PCB. Ideal for running microcontrollers from 12V and similar power supplies, or a million and one other uses.

Note: by default, the output is set to adjustable. To select one of the fixed voltages you must cut the tiny bridging track as shown below.

Specifications

• Input voltage: DC 4.5-24V
• Output voltage: adjustable (0.8-17V) or fixed output (1.8V, 2.5V, 3.3V, 5V, 9V or 12V)
• Output current: 3A maximum with power supply fitted to a small heatsink, 1.5A without heatsink.
• Conversion efficiency: up to 97.5% (6.5 input, 5V 0.7A output)
• Switching frequency: 500kHz
• Output ripple: 20mV (12V input, 5V, 3A output)
• Operating temperature: -40°C to + 85°C (the higher the temperature, the lower the output power)
• Full load temperature rise: 40°C
• Static current: 0.85 mA
• Load regulation: ±1%
• Voltage regulation: ±0.5%
• Dynamic response speed: 5% 200uS
• Output short circuit protection: Short term only, do not short-circuit continuously
• Input reverse polarity protection: None
• Enable control: Yes, high enabled, low disabled, high level 2-5V, low level 0V. Internal pull-up to V+, so can be left unconnected for correct operation.
• Dimensions: 20mm(L) x 11mm(W) x 5mm(high)