Invention Grant
US08385087B2 Extending achievable duty cycle range in DC/DC forward converter with active clamp reset
有权
在有源钳位复位的DC / DC正激转换器中扩展可实现的占空比范围
- Patent Title: Extending achievable duty cycle range in DC/DC forward converter with active clamp reset
- Patent Title (中): 在有源钳位复位的DC / DC正激转换器中扩展可实现的占空比范围
-
Application No.: US12880618Application Date: 2010-09-13
-
Publication No.: US08385087B2Publication Date: 2013-02-26
- Inventor: William Hall Coley , Charles Edward Hawkes
- Applicant: William Hall Coley , Charles Edward Hawkes
- Applicant Address: US CA Milpitas
- Assignee: Linear Technology Corporation
- Current Assignee: Linear Technology Corporation
- Current Assignee Address: US CA Milpitas
- Agency: McDermott Will & Emery LLP
- Main IPC: H02M3/335
- IPC: H02M3/335

Abstract:
Novel system and methodology are provided for controlling a DC/DC forward converter having a transformer with primary and secondary windings, a reset switch, and a first switch coupled to the primary winding of the transformer. The control system involves a PWM control circuit responsive to an output signal of the converter for producing a PWM signal to control switching of the reset switch, and the first switch. A period of the PWM signal includes an on-time interval for enabling transfer of power via the transformer when the first switch is on, and a reset time interval for enabling reset of the transformer when the reset switch is on. A maximum value of the on-time interval is pre-set to provide sufficient time for the reset. The reset switch is turned off when the PWM signal goes from a first level to a second level. A first delay period is set between time when the reset switch turns off and time when the first switch turns on. A first delay control circuit is provided for reducing the first delay time when the on-time interval approaches the maximum value. Further, the converter may include a second switch coupled to the secondary winding of the transformer. A second delay period shorter than the first delay period may be set between time when the reset switch turns off and time when the second switch turns on. A second delay control circuit may be provided for reducing the second delay period when the on-time interval approaches the maximum value.
Public/Granted literature
- US20110062782A1 EXTENDING ACHIEVABLE DUTY CYCLE RANGE IN DC/DC FORWARD CONVERTER WITH ACTIVE CLAMP RESET Public/Granted day:2011-03-17
Information query
IPC分类: