大功率降压同步DC/DC控制器CXSD6278驱动外部N通道mosfet的300kHz恒频电压模式同步开关控制器。 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
目录7.相关产品 产品概述 返回TOP The CXSD6278 is a 300kHz constant frequency voltagemode synchronous switching controller that drives exter-nal N-channel MOSFETs. When the input supply dropsclose to output, the upper MOSFET remains on, achiev-ing 100% duty cycle. Internal loop compensation is opti-mized for fast transient response, eliminating externalcompensation network. The precision 0.8V referencemakes this part suitable for a wide variety of low voltageapplications. Soft-start is internally set to 2ms, limitingthe input in-rush current and preventing the output fromovershoot during powering up.The CXSD6278 has over current and short circuitprotections. Over current protection is achieved by moni-toring the voltage drop across the high side MOSFET,eliminating the need for a current sensing resistor andshort circuit condition is detected through the FB pin. Ifeither fault conditions occur, the CXSD6278 would initiatethe soft-start cycle. After three cycles and if the fault condi-tion persists, the controller will be shut down. To restartthe controller, either recycle the VCC supply or momen-tarily pull the OSCSET pin below 1.25V.The CXSD6278 can be shutdown by pulling the OCSETpin below 1.25V. In shutdown, both gate drive signals willbe low. The controller is available in a small SOP-8package.产品特点 返回TOP • Operates from +5V Input • 0.8V Internal Reference Voltage - ±1.5% Accuracy Over Line, Load and Temperature • 0.8V to VCC Output Range • Full Duty Cycle Range - 0% to 100% • Internal Loop Compensation • Internal Soft-Start - Typical 2ms • Programmable Over-Current Protection - Lossless Sensing Using MOSFET RDS (ON) • Under-Voltage Protection • Drives External N-Channel MOSFETs • Shutdown Control • Small SOP-8 Package • Lead Free and Green Devices Avaliable (RoHS Compliant) 应用范围 返回TOP • Motherboard • Graphics Cards • Cable or DSL Modems, Set Top Boxes • DSP Supplies • Memory Supplies • 5V Input DC-DC Regulators • Distributed Power Supplies 技术规格书(产品PDF) 返回TOP 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!
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