Application Specific Discretes
A.S.D.
TM
FLC02-200D
February 1996
FIRE LIGHTER CIRCUIT
SOT82
(Plastic)
SPACE SAVING : MONOLITHIC FIRE LIGHTER
FUNCTION INTEGRATION
DEDICATED THYRISTOR STRUCTURE FOR
CAPACITANCE
DISCHARGE
IGNITION
OPERATION
HIGH PULSE CURRENT CAPABILITY
150A @ tp = 10
s
FEATURES
-
The FLC02 is a high performance planar dif-
fused technology adapted to high temperature
and rugged environmental conditions.
-
It has been developed especially for capaci-
tance discharge operation. The main applica-
tions are ignitor circuits such as :
fuel ignitiors / gas boilers...
Th : Thyristor for switching operation.
Z : Zener diode to set the threshold voltage.
D : Diode for reverse conduction.
R : 2 kOhm resistor.
DESCRIPTION
FUNCTIONAL DIAGRAM
1
2
3
Z
R
D
Th
pin 2
pin 1
pin 3
1/7
Symbol
Parameter
Value
Unit
R
th(j-a)
Thermal resistance junction to ambient
100
C/W
THERMAL RESISTANCE
ORDERING INFORMATION
FLC
02 - 200
D
FIRE LIGHTER CIRCUIT
PACKAGE D : SOT82
V
RM
200 = 200 V
CIRCUIT NUMBER : 02 = scr + diode + zener + resistance
(gate connected to pin 3)
Symbol
Parameter
Value
Unit
I
TRM
Repetitive surge peak on state current for thyristor
tp = 10
s
( note 1)
150
A
I
FRM
Repetitive surge peak on state current for diode
I
TSM
Non repetitive surge peak on state current
tp = 10ms
5
A
di/dt
Critical rate of rise time on state current
120
A/
s
T
stg
Tj
Storage junction temperature range
Maximum junction temperature
- 40 to + 150
+ 125
C
Toper
Operating temperature range
0 + 90
C
T
L
Maximum lead temperature for soldering during 10s
260
C
Note 1 : Test current waveform
ABSOLUTE RATINGS (limiting values) : 0
C < T
amb
< 90
C
200ms
10 s
FLC02-200D
2/7
ELECTRICAL CHARACTERISTICS
Symbol
Parameters
V
RM
Stand-off voltage
V
BO
Breakover voltage
V
T
On-state voltage drop
V
F
Diode voltage drop
I
RM
Leakage current
I
BO
Breakover current
I
I
F
VF
V
T
IRM
IBO
IBO
I T
VRM
V
BO
V
1
2
Symbol
Test Conditions
Value
Unit
V
F
I
F
= 2A
tp
1 ms
Tj = 25
C
MAX
1.7
V
DIODE (D) PARAMETER
Symbol
Test conditions
Value
Unit
I
RM
V
RM
= 200 V
Tj = 25
C
MAX
10
A
Tj = 120
C
MAX
100
A
V
BO
at I
BO1
Pin 3 (gate) open
Tj = 25
C
MAX
250
V
I
BO
1
at V
BO
Pin 3 (gate) open
Tj = 25
C
MAX
0.5
mA
I
BO
2
at V
BO
Pin 1 (cathode) and pin 3 (gate) in c/c
Tj = 25
C
MIN
40
mA
V
T
I
T
= 2A
tp
1ms
Tj = 25
C
MAX
1.7
V
THYRISTOR (Th) and ZENER (Z) PARAMETERS
Fig.1 : Relative variation of breakover current (I
BO
) versus junction temperature
0
20
40
60
80
0.4
0.6
0.8
1
1.2
1.4
Tj (
C)
Ibo (Tj) / Ibo (25
C )
IbO2
IbO1
FLC02-200D
3/7
BASIC APPLICATION
Rs
D
T
s
c
D
Th
Z
R
Ic
AC
MAINS
Ic
t
Sensor
The applications of the FLC02 using the capaci-
tance discharge topology operate in 2 modes :
- Ignition mode : Transistor T is OFF
- Blanking mode : Transistor T is ON
1) IGNITION MODE (Transistor T
OFF
)
PHASE 1:
The energy coming from the mains is stored into
the capacitorC. For that, the AC voltage is rectified
by the diode Ds.
PHASE 2 :
At the end of the phase 1, the voltage across the
capacitor C reaches the avalanche threshold of
the zener. Then a current flows through the gate of
the thyristor Th which fires.
The firing of the thyristor causes an alternating cur-
rent to flow through the capacitor C.
The positive parts of this current flow through C, Th
and the primary of the HV transformer.
The negativeparts of the current flow through C, D
and the primary of the HV transformer.
RS RESISTOR CALCULATION
The Rs resistor allows, in addition with the capaci-
tor C, to adjust the spark frequency and to limitate
the current from the mains. Its value shall allow
the thyristor Th to fire even in the worst case. In
this borderline case the system must fire with the
lower RMS mains voltage value while the break-
down voltage and current of the FLC are at the
maximum.
The maximum Rs value is equal to :
Rsmax
=
(
V
AC
min
x
2
) -
V
BO
max
I
BO1
max
FLC02-200D
4/7
Fig 2. : Spark frequency versus Rs and C
Fig. 3 : Voltage across the capacitance with Rs = 15 kOhms and C = 1
F
6
11
16
21
2
3
5
10
20
Rs (kOh ms )
F (Hz)
C=0.47
F
C=1
F
C=2.2
F
C=1.5
F
C=2.7
F
C=3.3
F
The couple Rs/C can be chosen with the previous
curve. Keep in mind the Rs maximum limit for
which the system would not work when the AC
mains is minimum.
The
next
curve
shows
the
beha vior with
Rs=15kOhms and C=1
F.
FLC02-200D
5/7
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