HV9906
Initial Release
HV9906 FlexSwitch
Features
Drive one or hundreds of LEDs including White LEDs
Programmable Current Source (mA to A)
Programmable Voltage Source (Steps Up or Down)
2
Integrator Lock Loop Technology (IL )
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
Seamlessly Change from AC to Battery Operation
TM
(Simple Off-Line/PFC & >9V DC/DC Switcher)
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 filters & compensation components, and which can
close the loop with feedback from a discontinuous waveform (eg.
LED current).
The HV9906 is capable of driving multiconverters, which have
been shown to provide the best performance to component count
trade off for wide conversion range applications like offline
converters. Applicable multiconverters include bucking & boosting
topologies, in isolated & non-isolated configurations, as well as
power factor correcting topologies from <1W up to 150W.
Proper choice of external components will allow the programming
of currents from <1mA to several amps and will allow stepping up
or stepping down from the input without the need to change
components. For example, the same HV9906 converter nominally
regulating to 60VDC output may operate from 12VDC, or from
rectified AC input to 265V
RMS
.
The HV9906 utilizes a programmable inversely proportional fast
feed forward algorithm to calculate output on time and a novel
2
Integrating Lock Loop (IL ) feedback with programmable threshold
differential sensing. The sensed feedback may be positive or
negative with respect to ground and the signal may be
discontinuous. In some topologies this control method permits the
elimination of the bulky input filter capacitor (a small high voltage
ceramic or film capacitor is required to maintain a high frequency
path). This algorithm when used with certain multiconverters 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
Automotive
Typical Application Circuit
1N4007
D1 D2
12VDC to 400VDC
or
65VAC to 280VAC
D4 D3
C1
0.047uF
400V
NPN Bipolar Transistor Array or Matched 2N2222
D5
MURS160
D6
MURS160
L2
15uH
Q1
Q2
Q3
Negative Voltage
C3
0.033uF
L1
56uH
D7
MURS160
C4
Optional
Q25
-
+
LED-1
Row 1
20mA
LED-1
Row 2
20mA
LED-9
Row 2
LED-10
Row 2
LED-1
Row 3
20mA
LED-9
Row 3
LED-10
Row 3
LED-1
Row 25
20mA
LED-9
Row 25
LED-10
Row 25
R1
8M
Von
R2
100k
C2
1uF
to
6.8uF
U1
GATE
NS
HV9906
PS
Vdd
AGND
PGND
+Vin
M1
IRFBC30AF
R3
900k
R4
300k
R5
100
LED-9
Row 1
1
07/23/02
Supertex, Inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: (408) 744-0100 FAX: (408) 222-4895 www.supertex.com
SUPERTEX [ Supertex, Inc ]
