HT7718, HK7718, 1.8V DC/DC 升压芯片

HK7718 与 HT7718 兼容，并有三种封装，分别为 TO-92, SOT-89 和 SOT-23。

General Description
The HK77XX 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 HK77XX consists of an oscillator, a PFMcontrol 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.

Features
* Low start-up voltage: 0.7V (T*.)
* High efficiency: 85% (T*.)
* High output voltage accuracy: 2.5%
* Output voltage: 2.7V, 3.0V, 3.3V, 5.0V
* Output current up to 200mA
* Ultra low supply current IDD: 5 A (T*.)
* Low ripple and low noise
* Low shutdown current: 0.5 A (T*.)
* TO-92, SOT-89, SOT-23 and SOT-25 package

Applications
* Palm*s/PDAs
* Portable communicators/Smartphones
* Cameras/Camcorders
* Battery-powered equipment