Sensitive charge pump doublers

Linear Technology Corporation announces the LTC3204B-3.3/5 charge pump doublers offered in the 2mm x 2mm DFN packages.

Featuring low-noise constant-frequency (1.2MHz) operation, the LTC3204B-3.3 generates a regulated boosted output voltage of 3.3V from a minimum input voltage of 1.8V (2AA cell alkaline or NiMH) at output currents up to 50mA. The LTC3204B-5 produces a 5V output from a minimum 2.7V (Li-Ion battery) input voltage at currents up to 150mA.

The LTC3204B is said to be ideal for applications sensitive to variable-frequency operation. The device's patented constant-frequency architecture ensures both low input and low output ripple, especially at light loads, to minimise switching noise.

Other features include automatic soft start circuitry to prevent excessive inrush current during start-up, load disconnect from the input during shutdown, plus current limit and thermal shutdown circuitry.

The LTC3204B's high switching frequency enables the use of tiny external ceramic capacitors, saving size and cost. Low external parts count of one flying capacitor and two bypass capacitors, in addition to the low profile DFN package, make the LTC3204B a compact solution for space-constrained applications.