1.5MHz Synchronous Dual Channel DC/DC Converter and 100mA LDO

The LTC3100 combines a high efficiency 700mA synchronous step-up converter, a 250mA synchronous stepdown converter and a 100mA LDO regulator. The LTC3100 features a wide input voltage range of 0.65V to 5V. The step-down converter can be powered by the output of the step-up converter or from a separate power source between 1.8V and 5.5V. The LDO can also be used as a sequencing switch on the output of the boost.

A switching frequency of 1.5MHz minimizes solution footprint by allowing the use of tiny, low profile inductors and ceramic capacitors. The switching regulators use current mode control and are internally compensated, reducing external parts count. Each converter automatically transitions to Burst Mode operation to maintain high efficiency over the full load range. Burst Mode operation can be disabled for low noise applications. The integrated LDO provides a third low noise, low dropout supply.

Anti-ringing circuitry reduces EMI by damping the boost inductor in discontinuous mode. Additional features include shutdown current of under 1μA and overtemperature shutdown. The LTC3100 is housed in a 16-lead 3mm × 3mm 0.75mm QFN package.

Applications

* Bar Code Readers

* Medical Instruments

* Low Power Portable Electronic Devices

* Extremely Compact Triple-Rail Solution

* Burst Mode® Operation, IQ = 15μA

* 1.5MHz Fixed Frequency Operation

* Power Good Indicators

* 700mA Synchronous Step-Up DC/DC

* 0.65V to 5V VIN Range

* 1.5V to 5.25V VOUT Range

* 94% Peak Efficiency

* VIN > VOUT Operation

* Output Disconnect

* 250mA Synchronous Step-Down DC/DC

* 1.8V to 5.5V VIN Range

* 0.6V to 5.5V VOUT Range

* LDO (VIN Internally Tied to VBST)

* 0.6V to 5.25V VOUT Range

* 200mV Dropout Voltage at 100mA

* Available in a 16-Lead 3mm × 3mm QFN Package