Linear Technology introduced dual-mode high-efficiency step-up charge pump

Linear Technology Corporation introduces the LTC3203-1 / B / B, a mode-selectable, high-efficiency 500-mA step-up charge pump in a compact 3mm x 3mm DFN package. The LTC3203B features a low noise, constant frequency (1MHz) operation mode and a wide 2.7V to 5.5V input voltage range with adjustable output voltage, whereas the LTC3203-1 and LTC3203B-1 have a 4.5V or 5V user selectable fixed output Voltage option to power the LED or logic circuit. These chips also feature user-selectable conversion modes (1: 1.5 and 1: 2) to optimize charge pump efficiency, high current LED backlighting and camera lamp power for cell phones and PDAs, USB powered products, and General 3.3V or lithium-ion battery to 5V voltage conversion.

The LTC3203-1 automatically bursts Mode operation at light loads to achieve low 120uA supply current. The LTC3203B and LTC3203B-1's patented constant-frequency architecture ensures low input and output ripple in all load conditions to minimize switching noise, making both devices ideal for applications that are sensitive to variable frequency operation . Other features of the LTC3203-1 / B / B-1 include an auto-soft-start circuit to prevent excessive inrush current at start-up, load and input shutdown during shutdown, and short circuit and thermal shutdown protection.

The high switching frequency of the LTC3203-1 / B / B-1 allows the use of tiny external ceramic capacitors, reducing the solution size and cost. The small number of external components (two floating capacitors at VIN and VOUT and two bypass capacitors) and a flat DFN package allow extremely compact solutions for space-constrained applications.

LTC3203EDD-1, LTC3203BEDD and LTC3203BEDD-1 in a flat 10-lead DFN (3mm x 3mm x 0.75mm) package are already shipping. In 1,000-unit quantities, each starting at $ 2.00.