PT6905_10 Datasheet, PDF (1/4 Pages) Princeton Technology Corp – 3-Stage Dimming LED Driver

DESCRIPTION
The PT6905 is a continuous mode inductive step-down
converter with three-stage dimming, designed for driving
single or multiple series white LEDs efficiently from a
voltage source higher than the output LED voltage. The
IC operates from an input supply between 6V and 36V
and provides three-stage dimming with output current of
up to 1.2Amp.
The PT6905 includes the internal switch and a high-side
output current sensing circuit, which uses an external
resister to set the average output current.
The PT6905 has a three-stage dimming function. That is
to say the output current will be adjusted to 100% when
the first time power on corresponding to stage-one, 30%
when the second time power on corresponding to
stage-two and 10% when the third time power on
corresponding to stage-three. The cycle will restart to
stage-one again when the fourth time power on. So this
cycle will go on if the power off time is no less than six
seconds according to the external capacitor Cs of 10μF.
And the power could be saved if less light needed.
BLOCK DIAGRAM
Preliminary PT6905
3-Stage Dimming LED Driver
FEATURES
• High Efficiency (up to 95%)
• Maximum 1.2A Output Current
• Wide Input Voltage: 6V ~ 36V
• Three-Stage Dimming
• Typical 5% Output Current Accuracy
• Thermal Shutdown 150℃ Typical
• SOT-89-5L Package
APPLICATIONS
• DC/DC LED Driver
• Low Voltage Industrial LED Lighting
• Low Voltage Halogen Replacement LEDs
• Decorative LED Lighting
• LED Table Lighting
Tel: [phone]‧Fax: [phone]‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan