| 摘要 |
Driver ( 150 ) for a gas discharge lamp ( 9 ) comprises: an arrangement of two MOSFET switches ( 61, 62 ) connected in series between two input terminals ( 51 a, 52 b); an inductor ( 73 ) connected in series with said lamp ( 9 ), this series arrangement being coupled to a node (P) between said two switches; a control unit ( 180 ) providing control signals (S 1 , S 2 ) to said two switches. During a first commutation interval ( 41 ), a lamp circuit current (ILC) has only a first direction while during a second commutation interval ( 42 ) said lamp circuit current has only an opposite direction. In each commutation interval ( 41, 42 ), during a first operational phase ( 43 ) said lamp circuit current has a continuously increasing level while during a second operational phase ( 44 ) said lamp circuit current has a continuously decreasing level. The control unit ( 180 ) is designed to generate its control signals (S 1 , S 2 ) such that said two switches are always, switched substantially simultaneously in counter-phase. The mosfets are used in reverse conduction m node also, to avoid body diode conduction (synchronous rectification).
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