Off-Line Current Source Controller
Introduction
The Supertex HV9906DB2 demo board contains all
circuitry necessary to demonstrate the features of the
HV9906 second order power supply controller. The
power converter of the demo board consists of an
input buck-boost stage and an output buck stage.
The output voltage polarity is negative. Due to its
unique quadratic input-to-output DC voltage transfer
ratio, the converter can operate directly off AC line to
produce low-voltage output without need for
electrolytic capacitors. HV9906 is designed for
optimal controlling this type of power converter or
other types of two-stage multi-converters.
Board Layout and Connections
HV9906DB2
The board is optimized for driving a 6V 400mA
(700mA max.) LED. However, it may be modified to
meet custom requirements.
Specification
Input Voltage 80 to 135VAC, 60Hz
Output Current 400mA ±10% (700mA max.)
Output Voltage 10V max.
Efficiency 62%
at Io=500mA, Vin=100VAC
WARNING!!!
Do not connect to scope ground or to the ground of other earth-grounded instruments. Doing so will short the AC line,
resulting in damage to the circuit and/or instruments. Either use an isolation transformer on the AC line, use a
differential probe, or use a floating, battery-powered instrument to make measurements.
WARNING!!!
No galvanic isolation. Dangerous voltages are present when connected to the AC mains.
1 07/23/02
Supertex, Inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: (408) 744-0100 FAX: (408) 222-4895 www.supertex.com
HV9906DB2
Instructions
NEG, RTN
Connect your LED to these terminals: negative to
NEG, positive to RTN.
E1, E2
Connect 80 to 135VAC, 60Hz line source to these
terminals: line to E1, neutral to E2. The input is
protected with a 0.5A fuse. IMPORTANT: Make sure
that your LED is connected to NEG and RTN
terminals. There is no open circuit protection
available in this demo board. Contact Supertex, Inc.
for the application circuit if protection is required.
GND
This is circuit common.
Note that since galvanic isolation is not provided,
connecting this point to an earth-grounded instrument
(such as an oscilloscope) will short the AC line,
resulting in circuit and/or instrument damage.
Also note that GND may be at higher potential with
respect to earth ground, even if the AC is switched
off. Use caution!
Do not connect to earth-ground.
Setting Output Current
Output current is preset to 400mA for this board.
Output current can be re-programmed according to
the following equation:
RR
76
Iout 1
−
=
RR
⋅
V
⋅
37
The average output current will come out 5-10%
smaller due to power transfer interruptions during the
AC line voltage cusps.
Schematic Diagram
B1
E1
F1
1/2A
E2
D1
D3
D2
S
4
0
F
D
D4
.1
C2
D5
MUR S16 0
L2
100uH
R1
22
MMBT2907
D6
MURS120
C30.033
M1
IRFR320
Q1
R4
976K
R5
12.1K
2
DUT
1
HV9906
4
8
6
3
5
7
C6
10uF
R6
121K
R7
2 07/23/02
Supertex, Inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: (408) 744-0100 FAX: (408) 222-4895 www.supertex.com
100K
L3
100uH
D7
MURS120
C5
0.1
R3
.47
NEG
LED1
LED
RTN
GND
HV9906DB2
Parts List
Item Reference Part Part Number Manufacturer Part No.
1 B1 Diode Bridge DF04S Diodes Inc. DF04S
2 C2 Cap, PEN Film 0.1uF 250V ECW-U2104KC9 Panasonic ECW-U2104KC9
3 C3 Cap, PEN Film 0.033uF 250V ECW-U2333KC9 Panasonic ECW-U2333KC9
4 C5 0.1 uF, 50V, 10%
5 C6 10 uF, 16V Tantalum Chip
6 D5 Diode, Ultra Fast, 600V 1A MURS160T3 On Semi MURS160T3
7 D6 Diode, Ultra Fast, 200V 1A MURS120T3 On Semi MURS120T3
8 D7 Diode, Ultra Fast, 200V 1A MURS120T3 On Semi MURS120T3
9 F1 Fuse, 1/2A, Slow Blow R452.500 Littelfuse R452.500
10 L2 100uH, 1.7A CTCDRH127-101 Central Technologies CTCDRH127-101
11 L3 100uH, 1.2A DO3316P-104 Coilcraft DO3316P-104
12 M1 MOSFET, 400V IRFR320 International Rectifier IRFR320
13 Q1 BJT, PNP MMBT2907 On Semi MMBT2907
14 R1 22 ohm, 1%, 1/8W
15 R3 0.47 ohm, 1%, 1/4W
16 R4 976K ohm, 1%, 1/8W
17 R5 12.1K ohm, 1%, 1/8W
18 R6 121K ohm, 1%, 1/8W
19 R7 100K ohm, 1%, 1/8W
20 U1 PWM/PFM IC HV9906 Supertex, Inc. HV9906
3 07/23/02
Supertex, Inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: (408) 744-0100 FAX: (408) 222-4895 www.supertex.com
The Supertex SuperNova Powers the Luxeon Star
Highlights: - 400mA (700mA when potted)
- Small 25mm x 25mm x 11mm size
- High reliability
- No electrolytic capacitors
- Operates directly off AC line (85VAC<Vin<135VAC)
- Maintains regulation down to 20VDC input
PCB Layout:
ig. 1 - Top view Fig. 2 – Bottom view
F
Waveforms:
Fig. 3 – Output Current (Vin = 120VDC) Fig. 4 – Output Current (Vin = 120AC)
Waveform Summary:
Fig. 3 shows continuous nature of the output
current. Peak-to-average current ratio is close to
unity.
Fig. 4 shows that current drops out of regulation
for short periods of time only during the AC line
cusps. (Switching ripple component is attenuated
for clarity.)
Fig. 5 shows the input current nature. The
converter delivers full output power to the output
Fig. 5 – Input Current and Voltage (Vin = 120VAC)
down to very low input voltage.
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