公开(公告)号：US20230043119A1

公开(公告)日：2023-02-09

申请号：US17749052

申请日：2022-05-19

Applicant: Richtek Technology Corporation

Inventor： Hung-Yu Cheng ,  Chi-Hsun Wu

IPC: H02M1/44 ,  H02M1/38 ,  H02M3/158

Abstract: A low EMI driver apparatus includes: a driver circuit configured to generate a driving signal according to a switch control signal, so as to drive at least one switch; and a driving strength control circuit configured to randomly control a driving strength of the driver circuit, thereby reducing an EMI generated when the at least one switch is driven according to the driving signal. In a specific form of the low EMI driver apparatus, the at least one switch includes plural switches, and the low EMI driver apparatus further includes: a dead time control circuit configured to randomly control a dead time between ON times of the plural switches, so as to reduce the EMI generated when the switches are driven according to the driving signal.

公开(公告)号：US20240097567A1

公开(公告)日：2024-03-21

申请号：US18453586

申请日：2023-08-22

Applicant: Richtek Technology Corporation

Inventor： Hung-Yu Cheng ,  Wan-Hsuan Yang ,  Chi-Hsun Wu

IPC: H02M3/158 ,  H02M1/00 ,  H02M1/088 ,  H03K7/08

CPC classification number: H02M3/158 ,  H02M1/0025 ,  H02M1/088 ,  H03K7/08

Abstract: A conversion control circuit is configured to generate a PWM (pulse width modulation) signal to control a power switch for switching an inductor to convert an input voltage to an output voltage. The steps of generating the PWM signal includes: enabling the PWM signal at a rising edge of a clock signal to turn on the power switch; disabling the PWM signal to turn off the power switch when an on-time exceeds a predetermined minimum on-time and the output voltage has reached an output level; triggering a next rising edge of the clock signal when the off-time exceeds a predetermined minimum off-time, the output voltage has not reached the output level, and a present cycle period of the clock signal has reached a predetermined cycle period.