| 摘要 |
A backlight drive circuit (1) comprises an LED constant-current driver chip (10) outputting a PWM signal, a power interface (20), a voltage transformation unit (30), a first switch unit (50), a second switch unit (60), a third switch unit (70) and a level conversion unit (40). The voltage transformation unit (30) comprises a primary coil (31) and a secondary coil (32). The first switch unit (50) is connected with the power interface (20) and the primary coil (31). The second switch unit (60), the secondary coil (32) and a first LED string (21) form a first current loop (LP1). The first switch unit (50) and the second switch unit (60) are switched on or off by receiving the PWM signal. The third switch unit (70), the primary coil (31) and a second LED string (22) form a second current loop (LP2). The level conversion unit (40) carries out the level conversion on the PWM signal, and then outputs the PWM signal to the third switch unit (70). Further provided are an electronic device (100) and a backlight drive method. |
