Transformerless, Switch Mode Boost Regulator, A Step-Up Converter

Using this switch mode regulator circuit, you can get a stable 12 volt output (500mA) although you just have 4,3 – 10V power supply. You can even boost a 3.5V input to 12V if the load draws only 100 mA or less. This switch mode voltage regulator use LTC1266 IC chip from Linear Technology. Here is the schematic diagram of the circuit:

The BINH control input is provided to turn off the burst mode of this switch mode regulator circuit. Burst mode increase efficiency when the load current is low, and this mode is switched on and off automatically when the BINH is grounded. Connect this BINH pin to voltage supply (3.5-10V) to turn off this burst mode feature. You can also connect this BINH control input to CMOS logic, either using discrete logic, switch, or microcontroller. A voltage of 2 Volt or more on this BINH pin disables the burst mode. [Circuit’s schematic diagram source: Linear Technology Application Notes]