PT6903_10 Datasheet, PDF (1/4 Pages) Princeton Technology Corp – High Brightness LED Driver

DESCRIPTION
PT6903 is a PFM high brightness LED driver control IC. It
allows efficient operation of driver current up to 1.0A
output, and the input range is from 7V to 36V. Moreover,
PT6903 controls the internal MOS at a modulated switch
frequency up to 800KHz. PT6903 drives a single or
multiple series LEDs at a constant-current control method;
thus, providing constant current light output and enhanced
reliability.
PT6903 has linear and PWM dimming functions. Output
current to an LED string can be programmed to any value
between its minimum value to its maximum value at the
linear dimming control input of PT6903. PT6903 provides
a low-frequency PWM dimming input that can accept an
external control signal with a duty cycle of 0~100% and a
frequency between 100Hz and a few KHz.
PT6903 integrates more protection functions. The
reliability of LEDs and device can be promoted by these
protection functions. PT6903 provides over current
protection when output short-circuit or LEDs current rises
up about two times setting current. PT6903 must be
power-up again if over current protection happens.
PT6903 also provides over temperature protection. There
are two ways to protect LEDs and device when
temperature rises up to limited level. One is internal
thermal-shutdown function. If internal temperature rises
up about 135℃, PT6903 will turn off switch. It will turn-on
again when internal temperature falls down about 115℃.
Another is temperature compensation function. This
function is only used for SOP8 package. An NTC
thermistor temperature monitoring circuit can be used to
LD pin. When system temperature rises up to some
limited level, the voltage on LD pin will fall under 240mV
and LED current will fall under setting value. This function
can reduce the temperature of system effectively.
BLOCK DIAGRAM
PT6903
High Brightness LED Driver
FEATURES
• >90% efficiency
• Wide input voltage range: 7V to 36V
• Constant current driver
• Applications up to 1.0A
• Linear & PWM dimming
• Thermal shutdown protection
• Over current protection
• Internal 40V power NMOS switch
APPLICATIONS
• DC/DC LED driver
• Low voltage industrial LED lighting
• Low voltage halogen replacement LEDs
• Decorative LED lighting
Tel: [phone]‧Fax: [phone]‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan