Features

Ø   Fixed 5V ± 4% Output

Ø   VIN Range: 2.8V to 4.5V

Ø   Output Current: Up to 100mA（VIN≥2.8V）

                                  Up to 250mA（VIN≥3.6V）

Ø   Constant Frequency Operation at All Loads

Ø   Low Noise Constant Frequency (400kHz) Operation

Ø   Automatic Soft-Start Reduces Inrush Current

Ø   Shutdown Current <1μA

Ø   Short-Circuit Protection

Ø   No Inductors

Ø   Available in Low Profile 6-Lead SOT23 Package

Typical Application Circuit

Description

The HX4004 is a low noise, constant frequency (400kHz) switched ca­pacitor voltage doubler. It produces a regulated output voltage from a 2.8V to 4.5V input. Low external parts count (one flying capacitor and two small bypass capacitors at VIN and VOUT) make the HX4004 ideally suited for small, battery-powered applications.

The HX4004 have thermal shutdown capability and can survive a continuous short circuit from VOUT to GND. Built-in soft-start circuitry prevents excessive inrush current during start-up.

High switching frequency enables the use of small ceramic capacitors. A low current shutdown feature disconnects the load from VIN and reduces quiescent current to <1uA.

The HX4004 is available in the SOT-23-6L power packages.

Applications

Ø   White LED Backlighting

Ø   Li-Ion Battery Backup Supplies

Ø   Local 3V to 5V Conversion

Ø   Smart Card Readers

Ø   PCMCIA Local 5V Supplies