Regulator offers 95% efficiency & 3MHz switching
The LTC3124, a 3MHz, current-mode, synchronous boost DC/DC converter, has been introduced by LinearTechnology. Featuring output disconnect and inrush current limiting, the dual-phase converter minimises component size while delivering lower output ripple, versus an equivalent single-phase device. The device's internal 2.5A per phase capable switches together to deliver 5A of switch current.
The device is suitable for supercapacitor-based backup power systems and Li-Ion/Polymer or multicell NiMH applications due to the 8V switches delivering output voltages as high as 15V, from an input voltage range of 1.8V at start-up (0.5V when running) to 5.5V. The converter delivers up to 1.5A of continuous output current at 12V from a 5V input, with synchronous rectification enabling efficiencies up to 95%. The Burst Mode operation lowers quiescent current to only 25µA, providing extended battery run time. The combination of the thermally enhanced DFN-16 package with a constant switching frequency of up to 3MHz, minimises both inductor and capacitor size and provides a compact solution footprint required in handheld applications.
The LTC3124 has internal switches with an RDS(ON) of only 130mΩ (N-channel) and 200mΩ (P-channel) to deliver efficiencies as high as 95%. The output disconnect feature allows the output to be completely discharged in shutdown and also limits the inrush of current during start-up, minimizing surge currents seen by the input supply. The LTC3124 regulates the output voltage when the input voltage exceeds the output voltage, enabling compatibility with any battery chemistry. For applications demanding the lowest possible noise operation, the LTC3124 can be set via an external pin to operate in a continuous frequency mode. This version runs in continuous mode at all current levels to minimize possible interference of switching noise with noise-sensitive circuitry, slightly reducing light load efficiency. Additional features include external synchronization, output overvoltage protection, and robust short-circuit protection.
LTC3124EDHC and LTC3124EFE are both available from stock in 16-lead 3mm x 5mm DFN and thermally enhanced TSSOP packages, respectively. 1,000-piece pricing starts at $3.26 each. Industrial grade versions, the LTC3124IDHC and LTC3124IFE, are guaranteed to operate over the -40°C to 125°C operating junction temperature range and a high temperature grade version, the LTC3124HFE is guaranteed to operate over -40°C to 150°C.