HT77XX -- PFM Step-up DC/DC Converter

General Description

The HT77XX 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 1.8V, 2.7V, 3.0V, 3.3V, 3.7V 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 HT77XX 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.

Features

  • Low start-up voltage: 0.7V (Typ.), 0.9V (Max.)
  • High efficiency: 85% (Typ.), VOUT>=2.7V
  • High output voltage accuracy: ±2.5%
  • Output voltage: 1.8V, 2.7V, 3.0V, 3.3V, 3.7V, 5.0V
  • Output current up to 100mA
  • Ultra low supply current IDD2: 4uA (Typ.)
  • Low ripple and low noise
  • Low shutdown current: 0.5µA (Typ.)
  • TO-92, SOT-89, SOT-23 and SOT-25 package

Technical Document

Other Information