Buck-boost charge pump boasts low conducted noise

Linear Technology has rolled out its latest buck-boost charge pump. The LTC3245 is a versatile 250mA high voltage buck-boost charge pump and it uses switched capacitor fractional conversion to maintain regulation over a wide range of input voltage from 2.7V to 38V and produces a regulated output of 3.3V, 5V or adjustable (2.5V to 5V).

The LTC3245's unique constant frequency architecture with reduced switching edge rates provides lower conducted and radiated noise compared to conventional switching regulators. The device has pin selectable Burst Mode operation which allows the user to trade off low output ripple for better efficiency/lower quiescent current. Other IC features include low external parts count with ceramic capacitor stability, soft-start circuitry to prevent excessive current flow during start-up, plus short circuit and thermal protection.

Internal circuitry automatically selects the conversion ratio (2:1, 1:1 or 1:2) to optimise efficiency as input voltage and load conditions vary. Low operating current (18μA with no load, 4μA in shutdown) and low external device count (three small ceramic capacitors and no inductors) make the LTC3245 ideally suited for low power, space constrained automotive/industrial applications such as automotive ECU/CAN transceiver supplies, industrial housekeeping supplies and efficient low power 12V to 5V conversion.

The LTC3245 is available in a low-profile (0.75mm) 3mm x 4mm 12-lead DFN with backside thermal pad and a 12-lead MSOP package with backside thermal pad. E- and I-grade operating junction temperature is -40°C to +125°C, while H-grade is -40°C to +150°C. 1000-piece pricing for the E grade starts at $2.80 each, and devices are available from stock.

Further information on the LTC3245 can be found here.