公开(公告)号：US11171560B2

公开(公告)日：2021-11-09

申请号：US16779764

申请日：2020-02-03

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Po-Yu Chiang ,  Hung-Yu Cheng

IPC: H02M1/36 ,  H02M3/07 ,  H02M1/08 ,  H01L27/092 ,  H03K3/03

Abstract: A switching regulator having a low start-up voltage includes a power stage and a switch control circuit. The switch control circuit includes a power control switch. The power control switch is formed by a low threshold voltage transistor having a first conductivity type in a semiconductor substrate. The low threshold voltage transistor having the first conductivity type includes a first lightly doped region having a second conductivity type which forms a channel region of the low threshold voltage transistor having the first conductivity type. The semiconductor substrate includes a second lightly doped region having the second conductivity type which is formed by a same manufacturing process as the first lightly doped region having the second conductivity type. The second lightly doped region having the second conductivity type forms adrift region of a high-voltage transistor having the second conductivity type in the semiconductor substrate.

公开(公告)号：US20200304018A1

公开(公告)日：2020-09-24

申请号：US16779764

申请日：2020-02-03

Applicant: RICHTEK TECHNOLOGY CORPORATION

Inventor： Po-Yu Chiang ,  Hung-Yu Cheng

IPC: H02M1/36 ,  H02M3/07 ,  H02M1/08 ,  H03K3/03 ,  H01L27/092

Abstract: A switching regulator having a low start-up voltage includes a power stage and a switch control circuit. The switch control circuit includes a power control switch. The power control switch is formed by a low threshold voltage transistor having a first conductivity type in a semiconductor substrate. The low threshold voltage transistor having the first conductivity type includes a first lightly doped region having a second conductivity type which forms a channel region of the low threshold voltage transistor having the first conductivity type. The semiconductor substrate includes a second lightly doped region having the second conductivity type which is formed by a same manufacturing process as the first lightly doped region having the second conductivity type. The second lightly doped region having the second conductivity type forms adrift region of a high-voltage transistor having the second conductivity type in the semiconductor substrate.