feature

Capacitor-specific thyristor structure discharge ignition operation

High pulse current capability: – 190 A, tp=10 microseconds

Quick start operation

Designed for high ambient temperatures (up to 120 degrees Celsius)

Benefits Space-saving integration through monolithic functions

High reliability of planar technology

illustrate

The FLC01 series is specially developed for capacitor discharge operation. The main application is gas lighters or igniters such as cookers/gas boilers/gas stoves. . . It offers fully integrated functions with high performance and reliability levels for harsh high temperature environments. –Th: Thyristor for switching operation –Z: Zener diode to set threshold voltage –D: Reverse conduction diode –R: 2 kΩ resistor

Application stage of the capacitor discharge lighter: The energy from the power supply is stored in the capacitor C in the first stage. Therefore, the AC voltage is rectified by the diode Ds. The second stage ends at the end of stage 1 when the voltage on capacitor C reaches the threshold of the avalanche zener. The current then flows through the gate of the triggered thyristor. – Start of thyristor causes AC current to flow through capacitor C – Positive part of current flows through C, Th and primary side transformer of high voltage – Negative part of current through C, D and high voltage primary transformer resistance calculation In addition to capacitor C, The Rs resistor also allows adjustment of the spark frequency. The current of the power supply will also be limited. Its value should allow the thyristors to fire evenly in the worst case. In this case, the system must start with a lower supply voltage value while the breakdown voltage and current of the FLC are at their maximum values. The maximum RS value is equal to:

Rs/C can be selected using the previous curve. Remember the RS maximum limit at which the system will not work when AC. Power is minimal.

The next curve on the next page shows the behavior for RS = 15 kΩ and C = 1 μF.

picture. Capacitor voltage Rs=15 kΩ, C=1μF, VBO=225 V

Peak current limit

The component is designed to withstand an ambient temperature of 120°C with repetitive surges of ITRM = 190 A for a pulse duration of 10 microseconds. Peak current versus pulse duration allows us to verify that the application is within FLC operating limits.

Power loss (for 10 microseconds, see picture)

To estimate power loss, use the following formula: – For Thyristor: P=1.18 x IT(AV)+0.035 I2T(RMS) For Diode: P=0.67 x IF(AV)+0.106 I2F(RMS)

package information

Epoxy resin complies with UL94, V0 lead-free package Recommended torque: 0.4 to 0.6 N m To meet environmental requirements, ST offers ECOPACK® packages in different grades, depending on their level of environmental compliance.