FAN7311 — LCD Backlight Inverter Drive IC
December 2007
FAN7311
LCD Backlight Inverter Drive IC
Features
High-Efficiency Single-Stage Power Conversion
Wide Input Voltage Range: 5V to 25.5V
Backlight Lamp Ballast and Soft Dimming
Reduced Number of Required External Components
Precision Voltage Reference Trimmed to 2%
ZVS Full-Bridge Topology
Soft-Start Capability
PWM Control at Fixed Frequency
Analog and Burst Dimming Function
Programmable Striking Frequency
Open-Lamp Protection
Open-Lamp Regulation
20-Pin SSOP/SOIC/DIP
Description
The FAN7311 provides all the control functions for a
series parallel resonant converter as well as a pulse
width modulation (PWM) controller to develop a supply
voltage. Typical operating frequency range is between
30kHz and 250kHz, depending on the cold cathode fluo-
rescent lamp (CCFL) and the transformer's characteris-
tics. FAN7311 uses a new patented phase-shift control.
20-SSOP
20-SOIC
Applications
LCD TV
LCD Monitor
1
1
20-DIP
1
Ordering Information
Part Number
FAN7311G
FAN7311GX
FAN7311M
FAN7311MX
FAN7311N
Package
20-SSOP
20-SSOP
20-SOIC
20-SOIC
20-DIP
Operating Temperature Range
Packing Method
Rail
Tape & Reel
-25°C to 85°C
Rail
Tape & Reel
Rail
All packages are lead free per JEDEC: J-STD-020B standard.
Protected by U.S. Patent: 5,652,479; 7,158,390.
© 2006 Fairchild Semiconductor Corporation
FAN7311 Rev. 1.0.7
www.fairchildsemi.com
FAN7311 — LCD Backlight Inverter Drive IC
Typical Application Circuits
Application
19-inch LCD Monitor
Lamps
4
Input Voltage
13V
1. Schematic
F1
FUSE
C22
220μF
25V
CN5
1
2
3
4
5
6
7
8
9
10
12505WR-10
C25
1μF
M1
C27
1μF
0
12V
IC1
OLP
OLR
FAN7311
RT1
OUTB
OUTA
VIN
PGND
OUTC
C26
R6
0.1μF
0
82kΩ
RT
0
SN
DN
0
0
GN
DN
OUTB
OUTA
C6
1
μF
R25
10kΩ
SP
DP
ON/OFF
R24
10kΩ
C1 0.22μF
C28
10nF
ENA
C7
10μF
TX1
C8
10μF
GP
DP
LTM190EX
1
HOT
CN1
CCFL
2
1
HOT
CN2
CCFL
COLD
0
0
C2
S_S
GND
0
0
J1
FDS8958A
0
DIM(0~3.3V)
REF
0
M2
1
μF
REF
ADIM
0
R2
56kΩ
R7
0Ω
0
0
SN
DN
OUTD
C5
220pF
CT
R5
27kΩ
RT
C4
4.7nF
BCT
RT
GN
DN
C10
15pF
C11
15pF
2
COLD
BDIM
R4
22kΩ
C21
10nF
R3
18kΩ
C3
4.7n
EA_OUT
EA_IN
0
0
0
R27
10kΩ
SP
DP
OLP1
GP
DP
OLP2
FDS8958A
OLR
D4
BAV70
FB
R26
1kΩ
C14
10nF
R13
1kΩ
C30
10nF
D6
BAV99
R16
1kΩ
D7
BAV99
R17
1kΩ
0
0
R8
100kΩ
R9
9.1kΩ
R15
10kΩ
0
0
0
FB
0
0
0
0
0
TX2
OLR
R14
100kΩ
0
1
HOT
CN3
CCFL
2
1
OLP1
OLP2
2
C12
15pF
C13
15pF
OLP3
HOT
CN4
CCFL
COLD
COLD
REF
0
OLP
Q1
C9
1μF
R1
330kΩ
R22
10kΩ
R23
10kΩ
OLP4
KST2222
D11
BAW56
D1
BAW56
R20
10kΩ
OLP3
R21
10kΩ
OLP4
C19
2.2nF
C20
2.2nF
OLR
D3
BAV70
D8
BAV99
D9
BAV99
0
0
R12
1kΩ
C29
10nF
R11
1kΩ
C15
10nF
R18
1kΩ
R19
1kΩ
0
D10
BAW56
C18
2.2n
C17
2.2n
0
0
0
FB
0
0
0
0
0
0
0
FAN7311 Rev. 04
Figure 10. Typical Application Circuit
2. Transformer Schematic Diagram
- Supported by Namyang electronics (http://www.namyangelec.co.kr)
FAN7311 Rev. 04
Figure 11. Transformer Schematic
3. Core & Bobbin
Core: EFD2124
Material: PL7
Bobbin: EFE2124
4. Winding Specification
Pin No.
5 --> 2
7 --> 9
Wire
1 UEW 0.45
φ
1 UEW 0.04
φ
Turns
19
2300
Inductance
115 µH
1.5 H
Leakage Inductance
21.5µH
280mH
Remarks
1KHz, 1V
1KHz, 1V
www.fairchildsemi.com
© 2006 Fairchild Semiconductor Corporation
FAN7311 Rev. 1.0.7
10