| 摘要 |
An exemplary backlight control circuit ( 20 ) includes a sampling circuit ( 210 ), a pulse width modulation integrated circuit ( 260 ), a primary switch unit ( 271 ), and two secondary switch units ( 272, 273 ) connected in series to the primary switch unit. The sampling circuit outputs voltage signals to control on-off states of the two secondary switch units. The two secondary switch units correspondingly control an on-off state of the primary switch unit, and the primary switch unit correspondingly controls an on-off state of the pulse width modulation integrated circuit.
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