Hi all,
I’m looking for a circuit that will convert a 3V supply from a coin cell to 5V (max 100mA). I’ve tried looking around the internet for circuits but they all involve a chip and as this is for a product I intend to put into mass production I cant afford to add a $3 maxim chip to each product. Is there a simple circuit that doesnt use a chip or uses a cheap chip that I could get, I get all my components from mouser.com.
Any help would be greatly appreciated,
Sephers.
You could also use a charge pump DC to DC converter like the [MCP1252-33X50 or the [MCP1253-33X50. The voltage is regulated to about 2.5%, they can provide up to 120mA and cost is around $1.50. Not having to use an inductor is another benefit (one less unique part in the BOM, less noise generated).](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010595)](http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010593)
You are never going to get 100 mA from a coin cell, even from a big 2032 ! They just don’t have that much energy in them and are meant for small steady loads. I suggest you use 2 or 3 NiMH AA or AAA size. They have nominal voltages of about 1.2 volts per cell.
The type of switching regulator whose output voltage is higher than its input’s is called a “boost regulator”. Power conversion efficiencies for them run from about 60% to 70%.