高效率升压转换器提供48V的IP电话-High-Effici
ip phones require that data and power on the same cable. a high voltage power source of 48v is required, to reduce the voltage drop in the cable. this application note describes a dc-dc step-up converter that can deliver the required 48v supply, from the 12v source typically available in the host of such systems. it delivers low-voltage ripple, essential to prevent data errors.
isolation is provided by the 12v power-supply. for a system with one or two ports, a custom-designed dc-dc converter is more suitable than power modules, or bricks, since bricks tend to be bulkier and are more expensive. they are more suitable for systems that support more ports, where the power demand is higher.
the max668 is an excellent choice for the design of a dc-dc step-up converter. the max668, a current-mode controller, operates in the pwm mode at medium and heavy loads, providing high-efficiency and low-noise. with power levels greater than 20w, efficiencies of more than 90% are achievable.
figure 1.
the circuit of figure 2 has a 48v output and can deliver current up to 1 ampere, enough to power a system with two ports. l2 and c8 form a post filter to further reduce the ripple voltage below 50mv. a switching frequency of 400khz was chosen as a compromise between switching loss and the size of inductor l1. increasing the value of gate resistance r7 will reduce emi noise, but increase switching loss. a value of 2.0ω was chosen. at an input voltage of 12v, a full load of 1 ampere and an output of 48v, the peak-peak voltage ripple was 36mv with a conversion efficiency of 91%.
figure 2.
MIC4827制作EL发光片驱动
新一代蓝牙低功耗产品HS6621消费类电子产品方案
无锡集成电路企业盈利能力获得资本认可 未来有望培育出若干上市企业
电气控制柜布局应该注意什么？
曝苹果正在研发iOS14系统 将在2020年发布
高效率升压转换器提供48V的IP电话-High-Effici
使用Renesas RZ/G2进行嵌入式人工智能推理
制动电阻器的主要功能_制动电阻器的维护
电动玩具的电池充电器内部拆解报告分析
人工智能技术发展的方向：ML和DL
modbus转profinet网关连接5台台达ME300变频器案例
骁龙855对比a12
三星GalaxyS8怎样更换电池
华为在自动驾驶等领域正式成立了智能车解决方案BU部门
CPU正式退位 属于GPU的高光时刻来了
S-function详解与模型参考自适应仿真案例
视觉效果公司选择NVIDIA Omniverse开展远程实时协作
恒温孵育箱调控温电路
酒精生产线DCS控制系统的设计
是德科技推出USB4™2.0版解决方案，优化设计性能、确保标准合规性
isolation is provided by the 12v power-supply. for a system with one or two ports, a custom-designed dc-dc converter is more suitable than power modules, or bricks, since bricks tend to be bulkier and are more expensive. they are more suitable for systems that support more ports, where the power demand is higher.
the max668 is an excellent choice for the design of a dc-dc step-up converter. the max668, a current-mode controller, operates in the pwm mode at medium and heavy loads, providing high-efficiency and low-noise. with power levels greater than 20w, efficiencies of more than 90% are achievable.
figure 1.
the circuit of figure 2 has a 48v output and can deliver current up to 1 ampere, enough to power a system with two ports. l2 and c8 form a post filter to further reduce the ripple voltage below 50mv. a switching frequency of 400khz was chosen as a compromise between switching loss and the size of inductor l1. increasing the value of gate resistance r7 will reduce emi noise, but increase switching loss. a value of 2.0ω was chosen. at an input voltage of 12v, a full load of 1 ampere and an output of 48v, the peak-peak voltage ripple was 36mv with a conversion efficiency of 91%.
figure 2.
MIC4827制作EL发光片驱动
新一代蓝牙低功耗产品HS6621消费类电子产品方案
无锡集成电路企业盈利能力获得资本认可 未来有望培育出若干上市企业
电气控制柜布局应该注意什么？
曝苹果正在研发iOS14系统 将在2020年发布
高效率升压转换器提供48V的IP电话-High-Effici
使用Renesas RZ/G2进行嵌入式人工智能推理
制动电阻器的主要功能_制动电阻器的维护
电动玩具的电池充电器内部拆解报告分析
人工智能技术发展的方向：ML和DL
modbus转profinet网关连接5台台达ME300变频器案例
骁龙855对比a12
三星GalaxyS8怎样更换电池
华为在自动驾驶等领域正式成立了智能车解决方案BU部门
CPU正式退位 属于GPU的高光时刻来了
S-function详解与模型参考自适应仿真案例
视觉效果公司选择NVIDIA Omniverse开展远程实时协作
恒温孵育箱调控温电路
酒精生产线DCS控制系统的设计
是德科技推出USB4™2.0版解决方案，优化设计性能、确保标准合规性