Document
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FLC21 FAMILY
LOW POWER FIRE LIGHTER CIRCUIT
Application Specific Discretes A.S.D.TM
FEATURES
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DEDICATED THYRISTOR STRUCTURE FOR CAPACITIVE DISCHARGE IGNITION OPERATION HIGH PULSE CURRENT CAPABILITY IFRM = 90A @ tp = 10µS AC OR DC OPERATION CAPABILITY WITH SUPPLY FROM THE AC MAINS OR A DC BATTERY.
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BENEFITS
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SPACE SAVING THANKS TO MONOLITHIC FUNCTION INTEGRATION HI G H RELIABI LI TY WI TH PLANAR TECHNOLOGY
TO92 (Plastic)
FUNCTIONAL DIAGRAM DESCRIPTION The FLC21 series have been developed especially for capacitance discharge operation. The main applications are: fuel ignitor, fuel or gas heater, gas range, cook top, barbecue, water heater, HVAC, portable ignitor, insect killers. It uses a high performance planar diffused technology device adapted to high temperature in rugged environmental conditions. The typical supply of the FLC21 fire lighter circuit is a DC battery or the AC mains. Th: Thyristor for the switching operation. Z: Zener diode to set the igniting threshold voltage. D: Diode for the reverse conduction. R: 2 kΩ resistor. DEVICE TYPE FLC21-135A FLC21-65A
pin 3
Z Th
D
R
pin 1
pin 2 not connected
APPLICATION BATTERY OPERATION 100V Mains
MODE Ignition Ignition
Jun 2000 - Ed: 4D
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FLC21 FAMILY
ABSOLUTE RATINGS (limiting values) Symbol ITRM IFRM dI/dt Tstg Tj Tamb TL Parameter Repetitive surge peak on state current for thyristor -30°C ≤ Tamb ≤ 120°C Repetitive surge peak on state current for diode -30°C ≤ Tamb ≤ 120°C Critical rate of rise on state current -30°C ≤ Tamb ≤ 120°C Storage junction temperature range Maximum junction temperature Operating temperature range Maximum lead temperature for soldering during 10s 50 - 40 to + 150 125 - 30 to + 120 260 A/µs °C °C °C tp = 10µs ( note 1) Value 90 Unit A
Note 1 : Test current waveform
10µs
100ms
THERMAL RESISTANCE Symbol Rth(j-a) Junction to ambient Parameter Value 150 Unit °C/W
ORDERING INFORMATION
FLC
FIRE LIGHTER CIRCUIT ITRM = 90A
2 1 -
135
A
PACKAGE A: TO92
135: VRM = 135V 65: VRM = 65V
CIRCUIT NUMBER: SCR + diode + Zener + Resistance
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FLC21 FAMILY
ELECTRICAL CHARACTERISTICS Symbol VRM VBO VT VF IBO IRM αT Parameters Stand-off voltage Breakover voltage On-state voltage Diode forward voltage drop Breakover current Leakage current Temperature coefficient for VBO
IT V BO VRM V T VF IRM I BO V
I IF
DIODE (D) PARAMETER Symbol VF IF = 1A Test Conditions tp ≤ 500µs Tj = 25°C Max. Value 1.7 Unit V
THYRISTOR (Th) and ZENER (Z) PARAMETERS Value Symbol IRM VBO IBO VT αT Fig.1: Relative variation of breakover current versus junction temperature.
k = IBO(Tj) / IBO(25°C) 2.5 2 1.5 1 0.5 0
Test conditions VRM = 65V for FLC21-65A VRM = 135V for FLC21-135A at IBO at VBO IT = 2A tp ≤ 500µs Tj = 25°C Tj = 125°C Tj = 25°C Tj = 25°C Tj = 25°C
FLC21-65A Min. 1 10 70 80 500 1.7 0.07
FLC21-135A 1 10 140 160 500 1.7 0.16
Unit µA µA V µA V V/°C
Typ. Max. Min. Typ. Max.
-20
0
20
40
60
80
100
Tj (°C)
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FLC21 FAMILY
Fig. 2: BASIC AC MAINS APPLICATION
Ic Ic t S1 Rs Ds c
Th AC Z D R
MAINS
Fig. 3: BASIC DC APPLICATION
Ic Ic t S1
DC/AC Oscillator
Ds
Rs
c
Th Z D R
1/ IGNITION MODE PHASE 1 The AC voltage is rectified by the diode Ds. The ignition energy is supplied by the mains and stored into the capacitor C.
PHASE 2 At the end of the phase 1, the voltage across the capacitor C reaches the avalanche threshold of the Zener diode Z. Then, a current flows through this Zener diode into the gate of the thyristor Th which is triggered. The thyristor turn on generates an alternating current through the capacitor C. Its positive parts flow through the capacitor C, the primary of the HV transformer and the thyristor Th. Its negative parts of the current flow through C, D and the primary of the H.V transformer.
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FLC21 FAMILY
RS RESISTANCE CALCULATION The Rs resistance allows, in addition with the capacitance C, to adjust the spark frequency and to limit the current supplied by the mains. This resistance allows the thyristor triggering in any requested cases. In worst cases, the system must fire when the a.c. line voltage is minimum while the breakdown voltage VBO and the current IBO of the FLC are maximum.
The maximum Rs value is equal to:
Rs max =
(V AC min. 2 ) − [V BO max .(1 + α T .( T amb − 25 ))] k . I BO *
* : see fig 1
Fig. 4: Spark frequency versus Rs and C
FLC21-65A
F (Hz)
50
Vac=100Vrms, Vbo=75V, Tamb=25°C
C=1 µF C=1 .5µF C=2 .2µF C=2 .7µF C=3 .3µF
F (Hz)
50
FLC21-135A
Vdc=300V , Vbo=150V , Tamb=25°C
C=1 µF C=1 .5µF C=2 .2µF
30 20
30 20
C=3 C=2
.7µF
.3µ F
10 10 10 12 15 18 22 27 33 39 47 10 12 15 18 22 27 33 39 47
Rs (k Ω )
Rs (k Ω )
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.
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FLC21 FAMILY
PACKAGE MECHANICAL DATA TO92 (Plastic)
DIMENSIONS REF.
A a B C
Millimeters Min. Typ. Max. Min. 1.35 4.70 2.54 4.40 12.70 3.70 0.45 0.173 0.500
Inches Typ. Max. 0.053 0.185 .