Features
STEVAL-ILL026V1
3 W non-isolated offline LED driver
demonstration board based on the VIPer22A-E
Data brief
■ Input voltage: 90 to 265 V
■
Provides 350 mA constant current for LEDs
■ Capable of driving 3 x 1 W LEDs in series with
RMS
high-precision constant current (± 5%
tolerance)
■ Overtemperature protection
■ LED open circuit protection
■ LED short-circuit protection
■ 230 V
input version with no electrolytic
AC
capacitor
■ EN55015 & EN6100-3-2 compliant
■ RoHS compliant
Description
The progress made in the field of LEDs is visible
on an almost day-by-day basis. Many high power
LEDs are currently on the market, such as 0.7 A
and 1 A devices. However, the most commonly
used LEDs are those with a current of 0.350 A.
This demonstration board is designed for 350 mA
LEDs and is capable of driving three 1 W LEDs in
series with high-precision constant current (± 5%
tolerance). The design is based on the VIPer22AE, which combines a dedicated current mode
PWM controller with a high voltage power
MOSFET on the same silicon chip.
STEVAL-ILL026V1
The internal control circuit offers a large input
voltage range on the V
pin, accommodates
DD
changes in auxiliary supply voltage, and supports
automatic burst mode in low load conditions. The
board also features protections against
overtemperature, overcurrent and overvoltage
conditions.
December 2009 Doc ID 16766 Rev 2 1/4
For further information contact your local STMicroelectronics sales office.
www.st.com
4
Schematic diagram STEVAL-ILL026V1
1 Schematic diagram
Figure 1. STEVAL-ILL026V1 schematic diagram
Vdd
Q1
Q1
R1
R1
R2
R2
BC557A
BC557A
D139V 500mW
D139V 500mW
R06
2
D
TH1R06
T
S
4
/
71
K
4
4K7 1/ 4
4
/
K1
0
R3
1
R3
10K 1/ 4
BC547A
Q2
BC547A
1
Vdd
DRAIN
DRAIN
C122uF50V
C122uF50V
Q2
C6
C6
R4
R4
10K1/4
10K1/4
2
1
E
C
UR
O
SOURCE
S
FB
FB
3
NTROL
O
CONTROL
C
4
/4
/
4k7 1
4k7 1
2
8
7
6
5
PER 22
I
V
VIPER 22
4
2
N
O
2
1
J2
CON2
C
J2
4
81/
K
R6
6K8 1/ 4
R6
6
50V
5
C
C5
uF
2
22uF50V
H
m
L2
1
1mH
L2
0nF 16V
330nF 16V
33
R5 1R5_1/4_1%
R5 1R5_1/4_1%
V
6V
6
1
1
F
F
4
n
C
C4
30
3
330n
2
6
0
TH1R
D4ST
D4
STTH1R06
FB
B
F
v
0v
5
50
4
F
.2u
C3
2
C3
2.2uF4
+
+
mA
0
100
10
-
1
1
L
H1m H
1m
2/4 Doc ID 16766 Rev 2
D3
D3
1
_10%
W
1
10
10 - 1W_10%
7
R7
R
1
J1
J
C
D
00VDC
400V
4
F
70n
/4
VDC
400
C7
C7
0nF
33
330nF 400 VDC/ 4 70 n F
3
+
DC
DC
0V
0
C8
C8
4
F
n
0
330nF 400V
33
E
G
D
RI
BRIDGE
B
2
-
-+
4
2
1
ON2
C
CON2
AM05447v1