Active Member
|
[China]
Address: Room 36B1-B2, Building C, Electronics Science & Technology Building Shennan Mid-Road, Shenzhen China
Contact name:Sharon Yang
Anterwell Technology Ltd. |
|
|
PFM Step-up DC/DC Converter
Features
►Low start-up voltage: 0.7V (Typ.) 
►High efficiency: 85% (Typ.)
►High output voltage accuracy: 2.5%
►Output voltage: 2.7V, 3.0V, 3.3V, 5.0V
►Ultra low supply current IDD: 5A (Typ.)
►Low ripple and low noise
►Low shutdown current: 0.5A (Typ.)
►TO-92, SOT-89, SOT-23 and SOT-25 package Applica
Applications
►Palmtops/PDAs
►Portable communicators/Smartphones
►Cameras/Camcorders
►Battery-powered equipment Ge
General Description
The HT77XXA series is a set of PFM step-up DC/DC converter with high efficiency and low ripple. The series features extremely low start-up voltage and high output voltage accuracy. They require only three external components to provide a fixed output voltage of 2.7V, 3.0V, 3.3V or 5.0V. CMOS technology ensures ultra low supply current and makes them ideal for battery-operated applications powered from one or more cells.
The HT77XXA consists of an oscillator, a PFM control circuit, a driver transistor, a reference voltage unit, and a high speed comparator. They employ pulse frequency modulation (PFM) for minimum supply current and ripple at light output loading. These devices are available in space saving TO-92, SOT-89, SOT-23 and SOT-25 packages. For SOT-25 package, it also build-in a chip enable function to reduce power consumption during shutdown mode.
