HV9906_04 Datasheet, PDF (1/11 Pages) Supertex, Inc – Simple Off-Line/PFC & >9V DC/DC Switcher

HV9906
HV9906 FlexSwitch^TM
(Simple Off-Line/PFC & >9V DC/DC Switcher)
Features
‰ Drive one or hundreds of LEDs including White LEDs
‰ Programmable Current Source (mA to A)
‰ Programmable Voltage Source (Steps Up or Down)
‰ Integrator Lock Loop Technology (IL²)
o Built in Soft Start
o Allows Discontinuous Feedback
o Eliminates Compensation Components
o Eliminates Output Averaging Filters
o Inherent Dither to Reduce EMI
‰ Eliminates High Voltage Input Electrolytic Capacitor
‰ Smallest and Most Reliable Off-Line Solution
‰ Isolated or Non-Isolated Applications
‰ Can be Operated Directly from Rectified AC Mains
‰ 10V to 400V Input Range Internal Regulator
‰ <1.5mA Operating Supply Current
‰ Programmable Feed Forward Regulation
‰ Programmable Feedback Sense Threshold (mV to V)
‰ Integrating Differential Sense Feedback
Applications
‰ LED driver
‰ Power Factor Correction
‰ Constant Current or Voltage Source
‰ Battery Charger / PWM Housekeeping Supplies
‰ Traffic Lights / Street Lights
‰ Back Lighting of Flat Panel Displays
‰ Advertising Signs
General Description
The Supertex HV9906 allows the development of the smallest
possible, most reliable, offline and wide DC/DC conversion range
converters for driving LEDs and other applications. The HV9906
combines internally all the components required to operate directly
from the rectified AC line with a feedback mechanism that
eliminates compensation components.
The HV9906 is capable of driving cascaded converters (multi-
converters), which have been shown to provide the best
performance to component count trade off for wide conversion
range applications like off-line converters with or without power
factor correction (PFC). Bulky and unreliable electrolytic capacitors
can be replaced with lower value non-electrolytic ones or
eliminated completely when using HV9906.
Proper choice of external components will allow the programming
of currents from <1mA to several amps.
The HV9906 utilizes a programmable inversely proportional fast
feed forward algorithm to calculate output on time and a novel
Integrating Lock Loop (IL²) feedback with programmable threshold
differential sensing. The sensed feedback may be positive or
negative with respect to ground and the signal may be
discontinuous. This algorithm when used with certain multi-
converters such as the flyback-buck, with a fixed load, results in
near constant frequency with only a small dither which helps meet
FCC requirements.
Typical Application Circuit
1
9/20/2004
Supertex, Inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: [phone] FAX: [phone] www.supertex.com