HT77S11 Datasheet | Holtek Semiconductor

.. HT77S10/HT77S11 High Efficiency Synchronous Step-Up DC/DC Converter Features - Low start-up voltage: 0.7V (Typ.) - High efficiency: HT77S10: 91% (Typ.) - Low ripple and low noise - Ultra low supply current: 20m A (Typ.) - Low shutdown current: 1m A (Max.) - Built-in voltage detector - 8-pin MSOP/SOP packages at IOUT=200m A, VIN=2.4V, VOUT=3.3V - High output voltage accuracy: ±4% - Output voltage: 3.3V, 5.0V or Adjustable Applications - Battery-powered equipment power source - Power source for cameras, camcorders, VCRs, - Power source for appliances, which require a higher PDAs, pagers, electronic data banks, and hand-held munication equipment operating voltage than that of the application batteries General Description The HT77S11 and HT77S10 are high efficiency PFM synchronous step-up DC-DC converters. The two devices although functionally similar are different in their output drive current capabilities. Synchronous rectification operation is used to increase device efficiency and to reduce the external ponent resulting in reduced product costs. The converter switching frequency, which can have a value up to 500KHz, will vary according to the load demands and according to the input voltage to keep the output voltage at the required level. The HT77S11 and HT77S10 have 0.7V start-up voltage, and will consume a typical quiescent current of 20m A. A shutdown mode is provided whereby the operating current will be reduced a very low value. The output voltage has two fixed voltages of 3.3V by setting FB to OUT pin and 5V by setting FB to GND pin, but can also be adjusted between a value of 1.8V~5.5V using two external resistors. With internal voltage detector function, the detected voltage can be set by using dividing resistor. Selection Table Part No. HT77S10 HT77S11 Current Limit 1.0A 8MSOP/SOP 0.55A Package Rev. 1.10 March 11, 2010 .. HT77S10/HT77S11 Block Diagram Note: - The FB pin is connected to an external...