发明名称 |
Soft start circuit for self-oscillating drivers |
摘要 |
A half bridge driver chip for driving a resonant load, such as a ballast, has first and second pairs to which an oscillation frequency timing circuit, matched to the resonant frequency of the load. A constant voltage drop circuit is connected to these input pins to vary the voltage at the pins as a linear function of the input voltage Vcc. Consequently, when Vcc is increasing during the start-up of the circuit, the resonant frequency is initially high but decreases to its operation value as Vcc increases. This produces a soft start characteristic and a timed preheat cycle of the resonant load. In one embodiment, the constant voltage drop circuit is a zener diode; in another embodiment, it is strings of anti-parallel connected diodes.
|
申请公布号 |
US5796215(A) |
申请公布日期 |
1998.08.18 |
申请号 |
US19960671655 |
申请日期 |
1996.06.28 |
申请人 |
INTERNATIONAL RECTIFIER CORPORATION |
发明人 |
PARRY, JOHN EDWARD;WOOD, PETER N. |
分类号 |
H05B41/24;G05F1/00;G05F1/10;H02M1/00;H02M1/36;H02M7/5375;H05B41/285;H05B41/298;(IPC1-7):H05B37/02 |
主分类号 |
H05B41/24 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|