www.fairchildsemi.com
KA7543
Advanced Feedback Dimming Ballast Control IC
Features
•
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•
•
•
•
•
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•
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Lamp Current Feedback
Soft Start on Feedback
Voltage Dimming (0V~2V) on Feedback
Switch off Control (Vdm=5V)
Soft Dimming Control
No Lamp Protection
One Lamp Detection for Feedback
Abnormal Protection
Low Start-up and Operating Supply Current
UVLO with 1.8V Hysteresis
Totem Pole Output
Trimmed 1.5% Internal Bandgap Reference
14-DIP & 14-SOP
Descriptions
The KA7543 is an advanced lamp current feedback dimming
control IC. This ballast control IC provides all of the
necessary features to implement wide range dimming
control, soft start and constant power consumption for
intelligent electronic ballast systems. The KA7543 is
optimized for advanced electronic ballast systems requiring
minimum board area. External component counts can be
reduced by adopting the KA7543. Current feedback control
method of the inverter status is one of the most attractive
merits in KA7543. Internal soft start circuitry eliminates the
need for external soft start discrete components. Voltage
controlled soft dimming circuit is built into the IC to control
the lighting output in a wide range. Protection circuitry, no
lamp protection, abnormal protection, one lamp detection,
UVLO, restart on lamp adding , have been added.
14-DIP
Applications
• Electronic Ballast
• Lighting Control System
• Half Bridge Drive Control System
1
14-SOP
1
Rev. 1.0.3
©2002 Fairchild Semiconductor Corporation
KA7543
Internal Block Diagram
Output stage
OUT1
1
14
OUT2
Frequency
divider
Protection reset
+
NC
2
-
Reset Cs
UVLO
9.5V
-
+
sw
2V Vref
(bandgap)
2V
Internal
bias
bias
7V
1.8V
7V Vz
Supply
Q
Q
+
+
2V
+
R
S
+
4V
-
Limiter
-
0.7V
-
13
NC
ict
55pF
8ict
12
Vcc
3
GND
sw
Oscillator
+
1V
Cc
4
5.7V
Dimming starter
-
4V
+
2V
5V regulator
+
11
Cdm
11µA
5.7V
Mirror
+
isr
5V
Switch
-
+
-
id
1/2
Mirror
idr
+
+
-
is-id
Selecter
20kΩ
-
+
3V
-
+
1V
5pF
8
Dimmer
2V
9
20kΩ
Gm +
-
Soft starter
2V
10
V5
5
-
5/2
is
Cs
Current amp
+
Vfb
6
Vr
5kΩ
-
Gm
+
ir
Vdm
30kΩ
Vab
7
3pF
+
S
-
2V
Abnormal protection
R
Q
Q
Vld
No-lamp pretection
2
KA7543
Pin Assignments
OUT2
NC
GND
Cdm
Cs
Vdm
Vld
KA7543
OUT1
NC
Vcc
Cc
V5
Vfb
Vab
Pin Definitions
Pin Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin Name
OUT1
NC
Vcc
Cc
V5
Vfb
Vab
Vld
Vdm
Cs
Cdm
GND
NC
OUT2
Drive Output 1
No Connection
Supply Voltage Input
Compensation Input
5V Voltage Source
Negative Feedback Input
Abnormal Protection Input
Lamp Detection Input
Dimming Control Input
Soft Start Time Control Input
Soft Dimming Control Input
Ground
No Connection
Drive Output 2
Pin Function Description
3
KA7543
Absolute Maximum Ratings
Parameter
Supply Voltage
Peak Drive Output Current
Drive Output Clamping Diodes
V
O
> V
CC
, or V
O
< -0.3
Operating Temperature Range
Storage Temperature Range
Power Dissipation
Thermal Resistance (Junction-to-Air)
Symbol
V
CC
I
OH
, I
OL
Iclamp
Topr
Tstg
Pd
θja
Value
30
±300
±10
-25 to 125
-65 to 150
1
123
Unit
V
mA
mA
°C
°C
W
°C/W
Absolute Maximum Ratings (−25°C≤Ta≤125°C)
− ° ≤ ≤
°
Parameter
Temperature Stability For Reference Voltage (Vref)
Temperature Stability For Operating Frequency (fs)
Symbol
∆Vref(Typ)
∆fs(Typ)
Value
20
8
Unit
mV
kHz
Electrical Characteristics
Unless otherwise specified, Vcc=12V, Ta=25°C
.
Parameter
UNDER VOLTAGE LOCK OUT SECTION
Start Threshold Voltage
UVLO Hysteresis
5V Reference Voltage(Note1)
SUPPLY CURRENT SECTION
Start Up Supply Current
Operating Supply Current
Dynamic Operating Supply Current (Note1)
CURRENT AMPLIFIER SECTION (NOTE1)
Output Sink Current
Output Source Current
Iea(i)
Iea(o)
Vfb = 2V
Vfb = 0V
12
12
15
15
18
18
µA
µA
I
ST
I
CC
I
DCC
Vcc=8.5V
Output not switching
fo = 50kHz, CI=1nF
-
-
-
0.2
7
8
0.27
9
12
mA
mA
mA
V
TH
(st)
HY(st)
V5
I5 = 0mA
V
CC
increasing
-
8.7
1.5
4.9
9.5
1.8
5
10.3
2.1
5.1
V
V
V
Symbol
Conditions
Min.
Typ.
Max.
Unit
4
KA7543
Electrical Characteristics
(Continue)
Unless otherwise specified, Vcc=12V, Ta=25
°
C
.
Parameter
1 Lamp Feedback Voltage
2 Lamp Feedback Voltage
Output Voltage High
Output Voltage Low
OSCILLATOR SECTION(NOTE1)
Reference Frequency
Reference Dead Time
Soft Start Frequency
Soft Start Time Current
Dimming Voltage Range
Dimming Start Voltage
Initial Dimming Output Voltage
OUTPUT 1/2 SECTION
Rising Time (Note2)
Falling Time(Note2)
Output Voltage With UVLO Activated
PROTECTION SECTION
Lamp Detection Voltage
Abnormal Detection Voltage
Switch Off Detection Voltage
No Lamp Detect Voltage
PROTECTION RESET SECTION
Protection Reset Voltage
Vpr
-
-
0.7
-
V
Vld
Vab
Vso
Vnd
-
-
-
-
2.5
1.6
4.7
0.85
3
2
5
1
3.5
2.4
5.3
1.15
V
V
V
V
tr
tf
Vomin(o)
Vcc =12V,CI =1nF
Vcc =12V,CI =1nF
V
CC
= 5V, I
O
=100µA
-
-
-
200
50
-
280
90
0.9
ns
ns
V
fref
td
fss
I
ss
∆Vdm
Vdm
Vdm
Vdm = 0V
Vdm = 0V
V
C
= 3.0V
V
C
= 3.0V
V
C
= 0V
V
C
= 0V
-
37
1.2
77
9.2
0
3.85
-0.1
45
1.4
-
11
-
4
0
53
1.6
-
12.8
2
4.15
0.1
kHz
µs
kHz
µA
V
V
V
Symbol
Vfb1
Vfb2
Vea(h)
Vea(l)
Vld = 2V
Vld = 4V
Vfb = 0V
Vfb = 2V
Conditions
Min.
0.425
0.85
5.5
-
Typ.
0.5
1
5.7
-
Max.
0.575
1.15
5.9
0.4
Unit
V
V
V
V
VOLTAGE INPUT DIMMING SECTION(NOTE1)
Notes :
1. This parameter should be tested in Vcc = 11V, 14V, 30V.
2. This parameter, although guaranteed, is not tested in production.
5
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