Download IC System and Advanced Technology Development

LED Driver Design with
iW3620 _14V350mA
Summary and Features :
1. LED driver, 14V, [email protected] ; Wide AC input range @90Vac- 264Vac
2 For Isolated or Non-isolated Applications
3. High Efficiency and Minimum Parts count
4. Meet EMI EN55015B-QP & AV limits
5. Fully protected against AC input UV, OV, O/P Short/Open, meet single
point failure test.
1. Specification
Description
Input
Voltage
Frequency
Open-load Input Power
(264VAC)
Output
Symbol
Min
Typ
Max
Units
VIN
fLINE
90
47
110/230
50/60
264
63
VAC
Hz
2 Wire
W
Output Voltage
Const
Voltage Output Current
VOUT_CV
IOUT_CV
A
Output Voltage
Const
Current Output Current
Total Output Power
Continuous Output Power
Over Current Protection
VOUT_CV
V
Efficiency
Comment
14
V
Measured at the PCB connector
Min Vout is depend on Vcc
IOUT_CV
0.35
A
POUT
IOUT_MAX
4
0.35
W
A
Auto-restart

82
%
Measured at end of PCB, (TA = 25 ℃)
°C
Free convection, sea level
Environmental
Conducted EMI
Meets EN55015B
Safety
Operation Temperature
14V/350mA LED Driver
Topr
50
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 2
2.Schematic circuit
14V/350mA LED Driver
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 3
3.Circuit Board Photograph
Top side
Bottom side
14V/350mA LED Driver
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 4
4.Transformer Design For 14V/350mA
Winding Start Pin-1 &
End Pin-2 in “Clockwise”
direction - looking from
Pin1/5 side of the
Bobbin
SCHEMATIC
2
Pin5
Copper foil
Connected
to Pin3
Pin1
A(S)
PRI
Primary 102T
1
4
Instruction for Start of first winding…
Secondary 18T
Anti-clockwise
Primary
Winding machine rotation
Secondary
3(F)
B(F)
Bias/sense 16T
4(S)
2UEW 0.15mm*3*16T Bias clockwise
3
A(F)
Triple Insulated Wire
0.28mm*1*18T –Secondary (Anti-Clockwise)
-----Electric polarity
3(S)
B(S)
Copper foil 8.5(W)*8(L)mm shielding
ELECTRICAL SPECIFICATIONS:
1.
2.
3.
Primary Inductance (Lp) = 1.5mH @10KHz
Primary Leakage Inductance (Lk)< = 45uH @10KHz
Electrical Strength = 3KV, 50/60Hz,1Min
2(F)
2UEW 0.24mm*1*34T – Primary (Clockwise)
MATERIALS:
1.
2.
3.
4.
5.
Core : EFD15 (Ferrite Material TDK PC40 or equivalent)
Bobbin : Primary=4pin secondary=4pin.
Magnet Wires Pri : Type 2-UEW
Magnet Wire (Sec) : Triple Insulated Wires
Layer Insulation Tape :3M1298 or equivalent.
2UEW 0.24mm*1*34T – Primary (Clockwise)
1(S)
2UEW 0.24mm*1*34T – Primary (Clockwise)
FINISHED :
1.
2.
Varnish the complete assembly
Core is connected to primary ground (pin3)
14V/350mA LED Driver
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 5
5. Bill of Material
Item
Qty.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
14V/350mA LED Driver
Ref.
U1
C5
C4
C1
C3
C2
C7
C8
R1
R2,R3
R9
R7
R5
R8
R13
R11
R4
R10
R12
R14
R6
BR1
D3
F1
L1
Q1
D4
D1
T1
Description
Cost (US Cent) / unit
iW3620, Off-line digital PWM Controller, SO-8
470pF, 50V, NPO, SMD-0603
68pF, 50V, NPO, SMD-0603
4.7uF, 400V, E-CAP, 105'C
2.2uF, 400V, E-CAP, 105'C
100pF, SMD-0603
100uF, 25V,Low ESR, E-cap,
1nF,1KV,SMD-1206
4.7KΩ ±5﹪, SMD-0805
510KΩ,±5﹪, SMD-1206
100KΩ±5﹪, SMD-1206
24KΩ±5﹪, SMD-0603
100KΩ±5﹪, SMD-0805
3KΩ ±5﹪, SMD-0603
20KΩ ±5﹪, SMD-0603
10KΩ ±5﹪, SMD-0805
3.3Ω ±1﹪, SMD-0805
10Ω ±5﹪, SMD-0603
1KΩ ±5﹪, SMD-0603
100Ω,±5﹪, SMD-0805
200Ω ±5﹪, SMD-0603
MB8S, SMD
1N4148 0.1A/100V, LL-34
10R,0.5W, FUSE Resistor
1mH, 0510
2N60, TO-251
SB2100
1N4007,SMD
EFD15, Transformer
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 6
6. Regulation, Efficiency Measurement
90
80
70
Eff(%)
60
50
40
30
20
10
0
80
100
120
140
160
180
200
220
240
260
280
Vin(Vac)
* Note: Output voltage measured at end of PCB.
14V/350mA LED Driver
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 7
7. Output VI Characteristics
* Note: Output voltage measured at PCB end, TAMB=25 ℃
VIN=110VAC, TAMB=25℃
VIN=230VAC, TAMB=25℃
V-I Curve
V-I Curve
Vout
Vout
16
15
14
13
12
11
10
9
8
7
16
15
14
13
12
11
10
9
8
7
0
100
200
300
400
500
0
200
300
400
500
Iout
Iout
14V/350mA LED Driver
100
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 8
8. VDS waveform
Test Condition:
VIN=264VAC, Iout_cc=350mA
Result:
VDS_MAX=484V
Remark: Mosfet Spec__2A 600V
14V/350mA LED Driver
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 9
9. Conducted EMI ( Input 230Vac Full Load is the worst case )
Live Peak Scan
Neutral Peak Scan
14V/350mA LED Driver
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 10
9. Conducted EMI ( Input 230Vac Full Load is the worst case )
Live AV Scan
Neutral AV Scan
14V/350mA LED Driver
iWatt Confidential – Do Not Copy
15 Jan 2009
Page: 11