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CXSD6279B电压模式和同步PWM控制器驱动双N通道mosfet控制监视和保护功能受控电源带欠压和过流保护的输出 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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目录 1.产品概述 2.产品特点 一,产品概述(General Description) The CXSD6279B is a voltage mode and synchronous PWM controller 1.)Simple Single-Loop Control Design Graphic Cards 需要详细的PDF规格书请扫一扫微信联系我们，还可以获得免费样品以及技术支持！ 五,产品封装图 (Package)
current limit. An internal 200μA current source will flow through this resistor, creating a voltage drop, which will be com-pared with the voltage across the high side MOSFET. current source charges this capacitor to 5.8V. The SS voltage clamps the error amplifier output, and Figure1 shows the soft-start interval. At t1, the SS voltage reaches the valley of the oscillator’s triangle wave. The PWM comparator starts to generate a PWM signal to control logic, and the loop com- pensation for the PW M converter (see Application Information). resis-tive divider across the output (V OUT). The output voltage is determined by: device. In shutdown, the SS is discharged and the UGATE and LGATE pins are held low. The EN pin is the open-collector, and it will not be floating. across the high-side MOSFET for over-current protection. BOOT (Pin 10) MOSEFT,a bootstrap circuit can be used to create a suitable driver’s supply. Connect the pin to the external MOSFET, and provides the gate drive signal for the lower MOSFET. the device is turned on; conversely, when the VCC is below the falling threshold, the device is turned off.
Output Capacitor Selection rather than the actual capacitance requirement. Therefore, select highperformance low ESR capacitors that are intended for switching regulator applications. In some applications,multiple capacitors have to be paralled to achieve the desired ESR value. If tantalum capacitors are used, makesure they are surge tested by the manufactures. If in doubt,consult the capacitors manufacturer. operation, select the capacitor voltage rating to be at least 1.3 times higher than the maximum input voltage. The maximum RMS current rating requirement is approximately IOUT/2 , where IOUT is the load current. During power up, the input capaci-tors have to handle large amount of surge current. If tanta-lum capacitors are used, make sure they are surge tested by the manufactures. If in doubt, consult the capacitors manufacturer.For high frequency decoupling, a ceramic capacitor be-tween 0.1μF to 1μF can be connected between the VCC and the ground pin. inductance, the lower the inductor’s current ripple. This will translate into lower output ripple voltage. The ripple current and ripple voltage can be approximated by: ripple current and the regulator load transient response time. A smaller inductor will give the regulator a faster load tran-sient response at the expense of higher ripple current and vice versa. The maximum ripple current occurs at the maximum input voltage. A good starting point is to choose the ripple current to be approximately 30% of the maxi-mum output current.Once the inductance value has been chosen, select an inductor that is capable of carrying the required peak cur-rent without going into saturation. In some types of inductors, especially core that is make of ferrite, the ripple 180 degrees phase shift in the control loop. A compensation network between the COMP pin and the ground should be added. The simplest loop compensation network is shown in the LC filter is given by:
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发表时间：2020-04-21浏览次数：135
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