Demonstration circuit 916 is a low noise regulated charge pump featuring the LTC3204B (constant frequency switching) in the 2X2 DFN package. There are two assembly versions, DC916A-A and DC916A-B for the LTC3204B-5 (5V output) and LTC3204B-3.3 (3.3V output) respectively. The DC916A-B produces a regulated 3.3V output from a 1.8V to 4.5V input. The guaranteed output current is 50mA from VIN between 1.9V and 4.5V, and 40mA for VIN less than 1.9V.
The circuit requires only three tiny 0603 surface mount capacitors and uses minimal board space. No inductor or diodes are needed. The circuit features automatic Burst Mode® operation at light loads to maintain low supply current.