US 12,232,230 B2
LED driving circuit and driving method thereof
Sang Suk Kim, Daejeon (KR); Jang Su Kim, Daejeon (KR); Ji Hwan Kim, Daejeon (KR); Kyeong Rok Lee, Daejeon (KR); and Jong Min Lee, Daejeon (KR)
Assigned to LX Semicon Co., Ltd., Daejeon (KR)
Filed by LX Semicon Co., Ltd., Daejeon (KR)
Filed on Oct. 26, 2022, as Appl. No. 17/974,288.
Claims priority of application No. 10-2022-0001511 (KR), filed on Jan. 5, 2022; application No. 10-2022-0001512 (KR), filed on Jan. 5, 2022; and application No. 10-2022-0045474 (KR), filed on Apr. 13, 2022.
Prior Publication US 2023/0217564 A1, Jul. 6, 2023
Int. Cl. H05B 45/33 (2020.01); G02F 1/1335 (2006.01); G02F 1/13357 (2006.01); H05B 45/325 (2020.01)
CPC H05B 45/325 (2020.01) [G02F 1/133514 (2013.01); G02F 1/133603 (2013.01); H05B 45/33 (2020.01)] 20 Claims
OG exemplary drawing
 
1. A light emitting diode (LED) driving unit comprising:
a first LED driving circuit configured to receive a serial clock signal from a microcontroller unit, output the serial clock signal to a second LED driving circuit, and adjust a driving current for a first light emitting diode; and
the second LED driving circuit configured to receive the serial clock signal outputted from the first LED driving circuit, output the serial clock signal to a third LED driving circuit, and adjust a driving current for a second light emitting diode, wherein
the microcontroller unit, the first LED driving circuit, and the second LED driving circuit are configured to sequentially transmit the serial clock signal, and
the first LED driving circuit comprises:
a first switch circuit configured to adjust a level of the driving current for the first light emitting diode according to a duty ratio of a pulse width modulation (PWM) signal; and
a second switch circuit configured to adjust the level of the driving current for the first light emitting diode by receiving a pulse amplitude modulation (PAM) signal.