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, 2.2V, 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 TO92, SOT89, SOT23 and SOT23-5 packages. For SOT23-5 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, 2.2V, 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.)
  • TO92, SOT89, SOT23 and SOT23-5 package

Technical Document

Other Information