The CL0116 Solar Lantern Controller IC


I’ve been playing with these simple Solar lantern controller ICs recently. They’re the chips used in most cheap solar garden lights. Akiba and I have built a couple of products around these chips and have more in the works.

They’re pretty amazing ICs given that they cost almost nothing and contain a complete NiMH charge controller, boost converter, and PWM LED driver.

sch_cl0116The basic circuit from the datasheet is shown to the left, and aside from the IC itself you just need to add a single inductor, NiMH battery, solar cell and of course the LEDs to complete the circuit.

It uses the solar cell both to charge the battery and as a light sensor. When voltage from the solar cell falls below 150mV the IC will switch into illumination mode and start powering the LEDs. Rather than a typical current limiting configuration, the IC slightly overdrives the LEDs but uses a 100KHz pulse-train to drive them which they suggest results in >90% efficiency.

Considering the IC basically costs nothing this is pretty impressive. I have a set of 10 ICs+inductors on my shop if anybody else wants to play with them.