发明名称 |
LED driver circuit and method, and system and method for estimating the junction temperature of a light emitting diode |
摘要 |
A driver circuit (10) for a light emitting diode comprises a first driver circuit (32, 32′, 32′) for generating a first current output for driving the light emitting diode, wherein the first driver circuit has a control switch for interrupting the supply of the first current output. A second driver circuit (50) is for generating a second current output for driving the light emitting diode, and the second driver circuit also has a control switch for interrupting the supply of the second current output. The overall output of the driver circuit comprises a pulse width modulated output current which alternates between a high current (Ihigh) generated by the first driver circuit and a low current (Ilow) generated by the second driver circuit. By providing separate driver circuits for two different current requirements, the circuits can be optimised for each function. For example the high current value can comprise an LED operation current, and the low current value can comprise a non-zero measurement current. |
申请公布号 |
US8278831(B2) |
申请公布日期 |
2012.10.02 |
申请号 |
US20090864740 |
申请日期 |
2009.01.27 |
申请人 |
HOOGZAAD GIAN;SCHMITZ HANS;LANGESLAG WILHELMUS H. M.;SURDEANU RADU;NXP B.V. |
发明人 |
HOOGZAAD GIAN;SCHMITZ HANS;LANGESLAG WILHELMUS H. M.;SURDEANU RADU |
分类号 |
H05B37/02;H05B39/04;H05B41/36 |
主分类号 |
H05B37/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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