Boost converter

Linear Technology has announced the LT8415, a low-noise micropower boost converter with integrated dual half-bridge switches.

The design requires 10.5 µA of quiescent current. Integrated high value output feedback divider resistors enable the device to regulate a 16 V output with less than 70 µA of total input current. Its small 25 mA switch current limit enables it to operate efficiently from high impedance sources, such as coin cell batteries, without any inrush current limitation.

The integrated N-channel and P-channel MOSFETs in each half-bridge are synchronously controlled by a single input pin and never turn on at the same time, maximising system reliability for applications such as MEMs relays. The internal MOSFETs are sized to drive capacitive loads ranging from a few pF to several nF.

The converter integrates the main switch, half-bridge switches, Schottky diodes and output disconnect on a single die, packaged in a 2 x 3 mm DFN. The 2.5 to 16 V input voltage range enables it to operate from single-cell Li-Ion batteries up to fixed 12 V input rails, delivering outputs up to 40 V.

The output voltage can be adjusted dynamically by driving the FBP pin with an external voltage.

The device can deliver over 700 µA of average output current at 34 V from a single Li-Ion cell, making it suitable for applications such as MEMs relays or biasing power. Both parts use a unique control technique that delivers efficiencies to 88% and low output ripple (<10 mV_PK-PK over a wide load current range.

Other features include integrated soft-start and overvoltage protection.