特点
1.5V to 5.5V Adjustable Output Voltage
Synchronous Rectification: Up to 95% Efficiency
1A Switch Current (LTC3423) or
2A Switch Current (LTC3424)
Fixed Frequency Operation Up to 3MHz
Wide Input Range: 0.5V to 5.5V (Operating)
Very Low Quiescent Current: 38μA (Burst Mode? Operation)
No External Schottky Diode Required
Synchronizable Switching Frequency
Burst Mode Enable Control
OPTI-LOOP? Compensation
Very Low Shutdown Current: <1μA
Small 10-Pin MSOP Package
典型应用
典型应用
描述
The LTC ? 3423 and LTC3424 are high efficiency, fixed frequency, step-up DC/DC converters that can regulate output voltages as low as 1.5V from a single cell. An applied voltage of at least 2.7V to the VDD pin is required to power the internal control circuitry.
The devices include a 0.16 Ohms N-channel MOSFET switch and a 0.21 Ohms P-channel synchronous rectifier. The LTC3423 is intended for applications requiring less than 0.75W of output power and the LTC3424 for 1.5W or less. Switching frequencies up to 3MHz are programmed with an external timing resistor and the oscillator can be synchronized to an external clock.
Quiescent current is only 38μA in Burst Mode operation, maximizing battery life in portable applications. Burst Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/SYNC pin has either a clock or is driven low then the operation is at constant fixed frequency.
Other features include a 1μA shutdown, thermal shutdown and current limit. The LTC3423 and LTC3424 are available in the 10-lead MSOP package. For applications requiring an output voltage greater than 2.6V, the LTC3401 and LTC3402 are recommended without the need of a separate voltage for the V DD pin.