ZHCSND7 September 2022 SN6507-Q1
PRODUCTION DATA
- 1 特性
- 2 應(yīng)用
- 3 說(shuō)明
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Parameter Measurement Information
- 8 Detailed Description
- 9 Application and Implementation
- 10Device and Documentation Support
- 11Mechanical, Packaging, and Orderable Information
封裝選項(xiàng)
機(jī)械數(shù)據(jù) (封裝 | 引腳)
- DGQ|10
散熱焊盤機(jī)械數(shù)據(jù) (封裝 | 引腳)
- DGQ|10
訂購(gòu)信息
8.3.1 Push-Pull Converter
Push-pull converters require transformers with center-taps to transfer power from the primary to the secondary as shown in Figure 8-1. When Q1 conducts, VIN drives a current through the lower half of the primary to ground, thus creating a negative voltage potential at the lower primary end with regards to the VIN potential at the center-tap. .
Figure 8-1 Switching Cycles of a Push-Pull ConverterAt the same time the voltage across the upper half of the primary is such that the upper primary end is positive with regards to the center-tap in order to maintain the previously established current flow through Q2, which now has turned high-impedance. The two voltage sources, each of which equaling VIN, appear in series and cause a voltage potential at the open end of the primary of 2×VIN with regards to ground.
Per dot convention the same voltage polarities that occur at the primary also occur at the secondary. The positive potential of the upper secondary end therefore forward biases diode CR1. The secondary current starting from the upper secondary end flows through CR1, charges capacitor C, and returns through the load impedance RL back to the center-tap.
When Q2 conducts, Q1 goes high-impedance and the voltage polarities at the primary and secondary reverse. Now the lower end of the primary presents the open end with a 2×VIN potential against ground. In this case CR2 is forward biased while CR1 is reverse biased and current flows from the lower secondary end through CR2, charging the capacitor and returning through the load to the center-tap.