HV9906
TM
HV9906 FlexSwitch
(Simple Off-Line/PFC & >9V DC/DC Switcher)
Features
General Description
Drive one or hundreds of LEDs including White LEDs
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.
Programmable Current Source (mA to A)
Programmable Voltage Source (Steps Up or Down)
Integrator Lock Loop Technology (IL2)
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Built in Soft Start
Allows Discontinuous Feedback
Eliminates Compensation Components
Eliminates Output Averaging Filters
Inherent Dither to Reduce EMI
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.
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
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.
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
Typical Application Circuit
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9/20/2004
Supertex, Inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: (408) 222-8888 FAX: (408) 222-4895 www.supertex.com