Flyback converter bootstrap type synchronous rectification drive circuit
A flyback converter and synchronous rectification technology, applied in the direction of DC power input conversion to DC power output, AC power input conversion to DC power output, instruments, etc., can solve the problem of negative voltage not being used, circuit complexity, loss, etc. question
Inactive Publication Date: 2016-08-24
上海英联电子系统有限公司 +1
View PDF3 Cites 5 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
The disadvantage is that it needs the same isolation device as the external drive, and the circuit is more complicated
[0007] In the self-drive and hybrid drive schemes, the driving voltage range of the synchronous rectification MOSFET on the secondary side is Vout*Nd / Ns, and its negative voltage is not used, and it may even become a source of loss, or affect the power between the windings of the transformer. The choice of transformation ratio, or unfavorable factors that need to be avoided
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0029] figure 1 A synchronous rectification scheme using an external drive method for the flyback converter. The PWM drive signal drives 102 the primary side MOSFET through the delay circuit 101, and at the same time reaches the secondary side through the 104 isolation circuit, and the 105 synchronous rectification driving circuit drives the 106 secondary side synchronous rectification MOSFET. When PWM is at high level, due to the effect of the high level delay circuit, when 102 is turned on, 106 is already in the off state, so 102 and 106 will not be in the on state at the same time; when PWM is at low level, 102 will immediately When it is turned off, 106 is also turned on immediately. Adjusting the corresponding circuit parameters can ensure that 102 and 106 will not be in common. 103 transformer transfers the power from the primary side to the secondary side, and 107 is the output filter capacitor.
[0030] figure 2 A self-driven synchronous rectification scheme is ado...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
A flyback power supply converter employ a voltage transformer driving winding to realize bootstrap type synchronization rectification driving. The flyback converter bootstrap type synchronous rectification drive circuit comprises a primary side switch tube, a voltage transformer, a bootstrap circuit, a drive circuit, a synchronous rectifier and an output filtering capacitor. Driven by PWM signals, an original side winding and an original side power switch tube of a voltage transformer convert an input power source into a pulse mode which is then transmitted to a secondary side, output of a secondary side drive winding passes through a bootstrap circuit and therefore voltage is improved, a synchronous rectifier is enabled to work when the output of the secondary side drive winding passes through the drive circuit, and output voltage is obtained after output of a secondary side main output winding passes through the synchronous rectifier and is filtered.
Description
Technical field: [0001] This patent relates to how to use a transformer drive winding to realize a bootstrap synchronous rectification drive circuit in a flyback power converter. Background technique [0002] In order to reduce power loss and improve conversion efficiency in power converters, using synchronous rectification is a very good solution, especially for low-voltage, high-current applications. This is because the voltage drop of the MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) used as the rectifier device is much lower than that of the corresponding diode device. [0003] The flyback converter is widely used in small and medium power converters because of its simple circuit structure and wide input voltage range. Correspondingly, the synchronous rectification flyback converter has also been widely used. The secondary side (output side) synchronous rectification scheme in the flyback converter is generally divided into three types: external drive, sel...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More IPC IPC(8): H02M3/335H02M7/217
CPCY02B70/10
Inventor 乔宗标
Owner 上海英联电子系统有限公司