Datasheet fan7314 Datasheet

FAN7314 LCD Backlight Inverter Drive IC

March 2006

FAN7314
LCD Backlight Inverter Drive IC

Features

High-efficiency single-stage power conversion

■

■

Wide input voltage range: 5V to 25.5V
Back light lamp ballast and soft dimming

■

■

Reduces number of required external components
Precision voltage reference trimmed to 2%

■

■

ZVS half-bridge topology

■

Soft start
PWM control at fixed frequency

■

■

Analog and burst dimming function
Programmable striking frequency

■

■

Open lamp protection
Open lamp regulation

■

■

20-Pin SOIC

Description

The FAN7314 provides all the control functions for use
as 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 CCFL and the
transformer’s characteristics.

Ordering Information

Product number Package Operating Temperature

FAN7314M 20-SOIC -25°C to 85°C

FAN7314MX

FPS™ is a trademark of Fairchild Semiconductor Corporation.

©2006 Fairchild Semiconductor Corporation

FAN7314 Rev. 1.0.1

1

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Internal Block Diagram

FAN7314 LCD Backlight Inverter Drive IC

RT

CT

S_S

RT1

EA_OUT

ADIM

EA_IN

BCT

BDIM

AGND

max. 2V

min. 0.5V

M

RT1

max. 2V

min. 0.5V

6µA

Oscillator

Striking

Logic

Va+α

2.65V

OLP

S_S

+
–

Solr 105µA

Sburst 85µA

–

+

Error Amp.

Sburst

UVLO

–
+
+

2.5V

Voltage

Reference

Internal Bias

OUTA

Output

Driver

OUTB

Output

Control

PGND

Logic

OUTC

Output

Driver

OUTD

1.4µA

UVLO

Solr

Q

Q

SET

S

R

CLR

2.5VREF

UVLO

+

–

2.5V 1.5V

+

–

2V

V

+α

OLP

V

OLP

OLP

OLR

REF

&

ENA

VIN

VIN

+
–

1.4V

+
–

UVLO 5V

FAN7314 Rev. 1.0.1

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Pin Assignments

FAN7314 LCD Backlight Inverter Drive IC

16

OUTC

15

14

13

RT1 OUTB OUTA VIN PGND OUTD CT RT BCT

20

19

18 17

FAN7314

1

OLP OLR ENA S_S

2

Pin Definitions

Pin Number Pin Name Pin Function Description

1 OLP Open Lamp Protection
2 OLR Open Lamp Regulation
3 ENA Enable Input
4 S_S Soft Start
5 GND Analog Ground
6 REF 2.5V Reference Voltage
7 ADIM Analog Dimming Input
8 BDIM Burst Dimming Input

9 EA_IN Error Amplifier Input
10 EA_OUT Error Amplifier Output
11 BCT Burst Dimming Timing Capacitor
12 RT Timing Resistor
13 CT Timing Capacitor
14 OUTD NMOSFET Drive Output D
15 OUTC PMOSFET Drive Output C
16 PGND Power Ground
17 VIN Supply Voltage
18 OUTA PMOSFET Drive Output A
19 OUTB NMOSFET Drive Output B
20 RT1 Striking Frequency Resistor

543

GND

REF ADIM BDIM EA_IN EA_OUT

12

11

9876

10

FAN7314 Rev. 1.0.1

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Absolute Maximum Ratings

For typical values T
–25

°

C

≤

T

≤

A

Symbol Parameter Value Unit

V

CC

Topr Operating Temperature Range -25 to 85

Tj Junction Temperature 150
Tstg Storage Temperature Range -65 to 150
R

θ

JA

Pd Power Dissipation 1.8 W

Notes:

1. Thermal resistance test board:
Size: 76.2mm x 114.3mm x 1.6mm(1S0P)
JEDEC standard: JESD51-2, JESD51-3

2. Assume no ambient airflow.

= 25

°

C, V

85

°

C and 5V

A

= 12V and for min/max values T

CC

≤

V

≤

25.5V, unless otherwise specified.

CC

is the operating ambient temperature range with

A

Supply Voltage 5 to 25.5 V

Thermal Resistance Junction-Air

(1, 2)

70

ESD Level

°

°

°

°

C/W

FAN7314 LCD Backlight Inverter Drive IC

C
C
C

Parameter Pins Conditions Level Unit

Human Body Model (HBM) All pins R = 1.5k
Machine Model (MM) All pins except for BDIM C = 200pF 300

BDIM 250

Ω

, C = 100pF 2000 V

Electrical Characteristics

For typical values T
–25

°

C

≤

T

≤

A

Symbol Characteristics Test Condition Min. Typ. Max. Unit

REFERENCE SECTION (Recommend X7R Capacitor)

∆

Vref Line Regulation 5

V25 2.5V Regulation Voltage 2.45 2.5 2.55 V

OSCILLATOR SECTION (Main)

fosc Oscillation Frequency T

Vcth CT High Voltage – 2.0 – V

Vctl CT Low Voltage – 0.5 – V

OSCILLATOR SECTION (Burst)

foscb Oscillation Frequency T

Vbcth BCT High Voltage – 2 – V

Vbctl BCT Low Voltage – 0.5 – V

85

°

C and 5V

= 25

A

°

C, V

= 12V and for min/max values T

CC

≤

V

≤

25.5V, unless otherwise specified.

CC

is the operating ambient temperature range with

A

≤

V

≤

25.5V – 2 25 mV

CC

= 25

°

A

C, Ct = 270pF

110.4 115 119.6 kHz

Rt = 18k
Ct = 270pF, Rt = 18k 108 115 122

= 25

°

A

C, Ctb = 10nF,

204.75 225 245.25 Hz

Rt = 18k
Ctb = 10nF, Rt = 18k 201 225 248

FAN7314 Rev. 1.0.1

4

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FAN7314 LCD Backlight Inverter Drive IC

Electrical Characteristics

For typical values T
–25

°

C

≤

T

≤

A

85

°

C and 5V

= 25

A

°

C, V

≤

(Continued)

= 12V and for min/max values T

CC

V

≤

25.5V, unless otherwise specified.

CC

is the operating ambient temperature range with

A

Symbol Characteristics Test Condition Min. Typ. Max. Unit

ERROR AMP SECTION

(1)
(1)

(1)

(1)

–80 –dB
– 1.5 – MHz

61 85 109 µA

R(EA_IN) = 60k

→

open lamp 1.3 1.5 1.7 V

0.1 Va

Ω

Va

+

0.4 Va

+

+

0.7 1.4 2.1 µA

= Vth–0.2 – 130 180 µA

CC

= 12V – 1.5 4 mA

CC

= 12V – 200 370 µA

CC

= 12V – Vcc – V

CC

= 12V Vcc–10.5 Vcc–8.5 Vcc–6.5 V

CC

= 12V 6.5 8.5 10.5 V

CC

= 12V – 0 – V

CC

V

= Vth–0.2 Vcc–0.3 – – V

CC

V

= Vth–0.2 – – 0.3 V

CC

V

= 12V, Cload = 2nF – 200 500 ns

CC

V

= 12V, Cload = 2nF – 200 500 ns

CC

0.7 V

Open Loop Gain
Unit Gain Bandwidth

VehFeedback Output High Voltage EA_IN = 0V 2.13 2.4 2.57 V

lsin Output Sink Current EA_OUT = 1.5V – – -1 mA

lsur Output Source Current EA_OUT = 1.5V 1 – – mA

Iolr EA_IN Driving Current On OLR 75 105 135 µA

Iburst EA_IN Driving Current On Burst

Dimming

Vfbh Feedback High Voltage On Burst

Dimming

SOFT START SECTION

I

Soft Start Current S_S = 2V 4 6 8 µA

SS

Vssh Soft Start Clamping Voltage 2.3 2.65 3 V

PROTECTION SECTION

Volp0 Open Lamp Protection Voltage 0 Start at open lamp 2.2 2.5 2.8 V
Volp1 Open Lamp Protection Voltage 1 Normal

Volr Open Lamp Regulation Voltage 1.75 2 2.25 V
Iolp Open Lamp Protection Charging

Current

UNDER VOLTAGE LOCK OUT SECTION

Vth Start Threshold Voltage – – 5 V

Ist Start Up Current V
Iop Operating Supply Current V
Isb Stand-by Current V

ON/OFF SECTION

Von On State Input Voltage 2 – 5 V
Voff Off Stage Input Voltage – – 0.7 V

OUTPUT SECTION

Vpdhv PMOS Gate High Voltage V

Vphlv PMOS Gate Low Voltage V
Vndhv NMOS Gate Drive Voltage V
Vndhv NMOS Gate Drive Voltage V

Vpuv PMOS Gate Voltage With UVLO

Activated

Vnuv NMOS Gate Voltage With UVLO

Activated
Tr Rising Time
Tf Falling Time

FAN7314 Rev. 1.0.1

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Symbol Characteristics Test Condition Min. Typ. Max. Unit

MAX./MIN. OVERLAP

Min. Overlap Between Diagonal

Switches

Max. Overlap Between Diagonal

Switches

(1)

(1)

DELA Y TIME

PDR_A/NDR_B

PDR_C/NDR_D

Notes:

1. These parameters, although guranteed, are not 100% tesed in production.

2. Specifications to -25°C to 85°C are guaranteed by design based on final characterization results.

(1)

(1)

fosc = 100kHz – 0 – %

fosc = 100kHz – 100 – %

Rt = 18k – 450 – ns
Rt = 18k – 450 – ns

FAN7314 LCD Backlight Inverter Drive IC

FAN7314 Rev. 1.0.1

6

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Function Description

UVLO: The under voltage lockout circuit guarantees

stable operation of the IC’s control circuit by stopping
and starting operation as a function of the Vin value. The
UVLO circuit turns on the control circuit when Vin
exceeds 5V. When Vin is lower than 5V, the IC’s standby
current is less than 200µA.

ENA: Applying voltage higher than 2V to the ENA pin

enables the operation of the IC. Applying voltage lower
than 0.7V to the ENA pin will disable the operation of the
inverter.

Soft start: The soft start function requires that the S_S
pin is connected through a capacitor to GND. A soft star t
circuit ensures a gradual increase in the input and output
power. The capacitor value connected to the S_S pin
determines the rate at which the duty ratio rises. It is
charged by a 6µA current source.

Burst oscillator & burst dimming: The timing capaci-
tors (BCTs) are charged by the reference current source,
which is formed by the timing resistor (R

). The timing

T

resistor’s voltage is regulated at 1.25V. The sawtooth
waveform charges up to 2V. Once this voltage is
reached, the capacitors begin discharging down to 0.5V.
Next the timing capacitors start charging again and a
new switching cycle begins. The burst dimming fre­quency can be programmed by adjusting the R
BC

values. The burst dimming frequency can be calcu-

T

and

T

lated as shown below:

FAN7314 LCD Backlight Inverter Drive IC

Main oscillator: The timing capacitors (CTs) are

charged by the reference current source. The current
source is formed by the timing resistor (R

). The timing

T

resistor’s voltage is regulated at 1.25V. The sawtooth
waveform (see top of next column) charges up to 2V.
Once this voltage is reached, the capacitors begin dis­charging down to 0.5V. Next, the timing capacitors start
charging again and a new switching cycle begins. The
main frequency can be programmed by adjusting the R
and CT values. The main frequency can be calculated as
shown below:

19

-------------------------------

fop =

32 RT C

T

f

burst

3.75

=

----------------------------------­96 RT BC

T

To avoid visible flicker, the burst dimming frequency
should be greater than 120Hz.

By comparing the input of BDIM pin with the 0.5 to 2V
triangular wave of the burst oscillator, the PWM pulses
for burst dimming. The PWM pulse controls EA_OUT’s
voltage by summing 85µA into the EA_IN pin.

T

FAN7314 Rev. 1.0.1

7 www.fairchildsemi.com

Open lamp regulation & open lamp protection: It is

necessary to suspend power stage operation if an open
lamp occurs, because the power stage has high gain.
When a voltage higher than 2V is applied to the OLR pin,
the part enters regulation mode and controls the
EA_OUT voltage. This limits the lamp voltage by sum­ming 105µA into the feedback node. At the same time,
the OLP capacitor, connected to the OLP pin, is charged
by the 1.4µA internal current source. Once it reaches

2.5V, the IC enters shut down where all the output is
high.

FAN7314 LCD Backlight Inverter Drive IC

Output Drives: The four output drives are designed so

that switches A and B, C and D never turn on simulta­neously. The OUTA-OUTB pair is intended to drive one
half-bridge in the external power stage. The OUTC­OUTD pair will drive the other half-bridge.

FAN7314 Rev. 1.0.1

8 www.fairchildsemi.com

Timing Diagram

The FAN7314 uses the half-bridge to drive CCFL.

EA_OUT

CT

SYNC

T

POUT A

NOUT B

FAN7314 LCD Backlight Inverter Drive IC

POUT C

NOUT D

FAN7314 Rev. 1.0.1

9 www.fairchildsemi.com

Typical Application Circuit

Application Lamps Input Volta ge

19 inch LCD Monitor 4 13V

1. Schematic

F1

FUSE

ON/OFF

R4
22k

C22
220u

25V

0

R24

10k

C28
10n

0

REF

R2
56k

C21

R3
18k

10n

0

0

IC1 FAN7314

OLP

OLR

ENA

C1 0.22u

S_S

0

GND

0

C2 1u

0

REF

ADIM

R7 0

BDIM

EA_IN

C3

EA_OUT

4.7n

REF

R1

OLP

330k

C9

Q1

1u

KST2222

D1
BAW56

0

C260.1u

0

R6 82k

PGND

OUTC

OUTD

R8

100k

R14
100k

RT1

OUTB

OUTA

VIN

CT

RT

BCT

C6

1u

C5 220p

R5 27k

C4

4.7n

OUTB
OUTA

RT

0

0

J1
0

0

0

0

RT

OLR

0

D11
BAW56

OLP3 OLP4

R21

R20

10k

10k

D10
BAW56

C18

C17

2.2n

2.2n

0

0

CN5

12505WR-10

1

13V

2
3
4
5
6
7
8
9
10

0

DIM ( 0~3.3V)

FAN7314 LCD Backlight Inverter Drive IC

C25

C27

1u

1u

M1

0

SN

GN

R25

SP

10k

GP

FDS8958A
M2

0

SN

GN

R27

SP

10k

GP

FDS8958A

R15

10k

R9

9.1k

0

R22

R23

10k

10k

C19

C20

2.2n

2.2n

00

0

0

DN

DN

C7 10u

DP

DP

DN

DN

DP

DP

FB

C8 10u

TX1

0

OLR

D4
BAV70

R26
1k

0 0

TX2

OLP2OLP1

0

OLR

D3
BAV70

R12
1k

0 0

LTM190EX

1

HOT

CN2
CCFL

2
C10
15p

C14
10n

0 0

C11
15p

OLP1

C30

R13

10n

1k

0

FB

C12
15p

C29
10n

0

C13
15p

OLP3 OLP4

R11

C15

1k

10n

0

COLD

OLP2

D6
BAV99

0

D8
BAV99

0

D7

BAV99
R17
1k

0

0

1

1

HOT

2

COLD

R18
1k

0

2

CN4
CCFL

D9
BAV99

0

1

HOT

CN1
CCFL

2

COLD

R16
1k

HOT

CN3
CCFL

COLD

R19
1k

0

FB

2. Transformer Schematic Diagram

Supported by Namyang electronics (http://www.namyangelec.co.kr)

1

6

9

8

234567

3. Core & Bobbin

■ Core: EFD2124

■ Material: PL7

■ Bobbin: EFE2124

9

7

1

FAN7314 Rev. 1.0.1

10 www.fairchildsemi.com

4. Winding Specification
Pin No. Wire Turns Inductance Leakage Inductance Remarks

5 → 2 1 UEW 0.45 φ 12 180µH 7.2µH 1KHz, 1V
7 → 9 1 UEW 0.04 φ 2430 (270 x 9) 7.2H 330mH 1KHz, 1V

5. BOM of the Application Circuit

Part Ref. Value Description/Vendor Part Ref. Value Description/Vendor

Fuse C5 220p 50V 1608 J

F1 24V 3A Fuse C6 1µ 50V 2012 K

Resistor (SMD) C7 10µ 16V 3216
R1 330K 1608 J C8 10µ 16V 3216
R2 56K 1608 F C9 1µ 16V 1608 K
R3 18K 1608 F C10 15p 3KV 3216
R4 22K 1608 F C11 15p 3KV 3216
R5 27K 1608 F C12 15p 3KV 3216
R6 82K 1608 F C13 15p 3KV 3216
R8 100K 1608 F C14 10n 50V 1608 K
R9 9.1K 1608 F C15 10n 50V 1608 K

R11 1K 1608 F C17 2.2n 50V 1608 Z
R12 1K 1608 F C18 2.2n 50V 1608 Z
R13 1K 1608 F C19 2.2n 50V 1608 Z
R14 100K 1608 F C20 2.2n 50V 1608 Z
R15 10K 1608 F C21 10n 50V 1608 Z
R16 1K 1608 F C25 1µ 50V 2012 K
R17 1K 1608 F C26 0.1µ 16V 1608 K
R18 1K 1608 F C27 1µ 50V 2012 K
R19 1K 1608 F C28 10n 50V 1608 Z
R20 10K 1608 J C29 10n 50V 1608 K
R21 10K 1608 J C30 10n 50V 1608 K
R22 10K 1608 J Diode / TR (SMD)
R23 10K 1608 J D1 BAW56 Fairchildsemi
R24 10K 1608 J D3 BAV70 Fairchildsemi
R25 10K 1608 J D4 BAV70 Fairchildsemi
R26 1K 1608 F D6 BAV99 Fairchildsemi
R27 10K 1608 J D7 BAV99 Fairchildsemi

Capacitor (SMD) D8 BAV99 Fairchildsemi
C1 0.22µ 16V 1608 K D9 BAV99 Fairchildsemi
C2 1µ 50V 2012 K D10 BAW56 Fairchildsemi
C3 4.7n 50V 1608 K D11 BAW56 Fairchildsemi
C4 4.7n 50V 1608 K Q1 KST2222 Fairchildsemi

FAN7314 LCD Backlight Inverter Drive IC

FAN7314 Rev. 1.0.1

11 www.fairchildsemi.com

5. BOM of the Application Circuit (Continued)
Part Ref. Value Description/Vendor Part Ref. Value Description/Vendor

Electrolytic capacitor Wafer (SMD)

C22 220µ 25V CN1 35001WR-02A

MOSFET (SMD) CN2 35001WR-02A
M1 FDS8958A Fairchildsemi CN3 35001WR-02A
M2 FDS8958A Fairchildsemi CN4 35001WR-02A

Transformer (SMD) CN5 12505WR-10
TX1 EFD2124 Supported by Namyang electronics
TX2 EFD2124

(http://www.namyangelec.co.kr)

FAN7314 LCD Backlight Inverter Drive IC

FAN7314 Rev. 1.0.1

12 www.fairchildsemi.com

Mechanical Dimensions

20-pin SOIC Package

FAN7314 LCD Backlight Inverter Drive IC

20

11

Symbol

A .093 .104 2.35 2.65
A1 .004 .012 0.10 0.30
B .013 0.33
C .009 .013 0.23 0.32
D .496 .512 12.60 13.00
E .291 .299 7.40 7.60
e
H
h
L .016 .050 0.40 1.27
N20 20

α

ccc .004 0.10——

Notes:

1.

Dimensioning and tolerancing per ANSI Y14.5M-1982.

2.

"D" and "E" do not include mold flash. Mold flash or
protrusions shall not exceed .010 inch (0.25mm).

3.

"L" is the length of terminal for soldering to a substrate.

4.

Terminal numbers are shown for reference only.

5.

"C" dimension does not include solder finish thickness.

6.

Symbol "N" is the maximum number of terminals.

Inches

Min. Max. Min. Max.

.020 0.51

.050 BSC 1.27 BSC
.394 .419 10.00 10.65
.010 .029 0.25 0.75

0° 8° 0° 8°

Millimeters

Notes

5
2
2

3
6

1

A

e

FAN7314 Rev. 1.0.1

EH

10

D

A1

B

SEATING
PLANE

– C –

LEAD COPLANARITY

ccc C

13 www.fairchildsemi.com

α

h x 45°

C

L

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The following are registered and unregistered trademarks Fairchild Semiconductor owns or is authorized to use and is
not intended to be an exhaustive list of all such trademarks.

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ActiveArray™
Bottomless™

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Build it Now™
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E

CMOS™
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Across the board. Around the world.™
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PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY
ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT

CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.

LIFE SUPPORT POLICY

®

FAST
FASTr™

LittleFET™

FRFET™
GlobalOptoisolator™
GTO™
HiSeC™

2

I

C™
i-Lo™
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IntelliMAX™

®

ISOPLANAR™

MICROCOUPLER™
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OPTOLOGIC

®

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TINYOPTO™

TruTranslation™

UHC™

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UniFET™

®

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®

®

FAN7314 LCD Backlight Inverter Drive IC

FAIRCHILDíS PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.
As used herein:

1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant into
the body, or (b) support or sustain life, or (c) whose
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
reasonably expected to result in significant injury to the
user.

PRODUCT STATUS DEFINITIONS

Definition of Terms

Datasheet Identification Product Status Definition

Advance Information

Preliminary

No Identification Needed

Formative or
In Design

First Production

Full Production

2. A critical component is any component of a life
support device or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or

effectiveness.

This datasheet contains the design specifications for
product development. Specifications may change in
any manner without notice.

This datasheet contains preliminary data, and
supplementary data will be published at a later date.
Fairchild Semiconductor reserves the right to make
changes at any time without notice in order to improve
design.

This datasheet contains final specifications. Fairchild
Semiconductor reserves the right to make changes at
any time without notice in order to improve design.

Obsolete

FAN7314 Rev. 1.0.1

Not In Production

This datasheet contains specifications on a product
that has been discontinued by Fairchild semiconductor.
The datasheet is printed for reference information only.

Rev. I18

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