访问电脑版页面

导航:老古开发网手机版其他

Allegromicro STR-X6757离线准谐振SMPS解决方案

导读:
关键字:
       Allegromicro 公司的STR-X6757是离线准谐振开关稳压器,具有比通常的PWM解决方案更低的EMI噪音特性,特别是频率大于2MHz时. STR-X6757采用TO-3P封装,包含控制器芯片(MIC)和650 VDSS/0.62Ω RDS(on)的MOSFET,230VAC输入时输出功率高达320W,通用电压输入达到165W,主要用于STB, LCD PC监视器,LCD TV,打印机和扫描仪.本文介绍STR-X6757主要特性和优势, 方框图和典型应用电路.

STR-X6757: Off-Line Quasi-Resonant Switching Regulators

The STR-X6757 is a quasi-resonant topology IC designed for SMPS applications. It shows lower EMI noise characteristics than conventional PWM solutions, especially at greater than 2 MHz. It also provides a soft-switching mode to turn on the internal MOSFET at close to zero voltage (VDS bottom point) by use of the resonant characteristic of primary inductance and a resonant capacitor.

The package is a fully molded TO-3P, which contains the controller chip (MIC) and MOSFET, enabling output power up to 320 W at 230 VAC and 165 W at universal input. The bottom-skip mode skips the first bottom of VDS and turns on the MOSFET at the second bottom point, to minimize an increase of operating frequency at light output load, improving systemlevel efficiency over the entire load range.

There are two standby modes available to reduce the input power under very light load conditions. The first is Auto-Standby mode, which is internally triggered by periodic sensing, and the other is a manual standby mode, which is executed by clamping the secondary output. In general applications, the manual standby mode reduces the input power further compared to Auto-Standby mode.

STR-X6757主要特性和优势:

? Quasi-resonant topology IC- Low EMI noise and soft switching

? Bottom-skip mode- Improved system efficiency over the entire output load by avoiding increase of switching frequency

? Auto-Standby mode- Lowers input power at very light output load condition

? Avalanche-guaranteed MOSFET- Improves system-level reliability and does not require VDSS derating

? 650 VDSS / 0.62 Ω RDS(on)

? Various protections - Improved system-level reliability

? Pulse-by-pulse drain overcurrent limiting

? Overvoltage Protection (bias winding voltage sensing),with latch

? Overload Protection with latch

? Maximum on-time limit

STR-X6757应用:

Set Top Box

LCD PC monitor, LCD TV

Printer, Scanner

SMPS power supplies



图1.STR-X6757方框图

图2.STR-X6757典型应用电路
来源:电子设计应用   作者:  2009/12/7 0:00:00
栏目: [ ]

相关阅读

安森美推出新的高功率图腾柱PFC控制器,满足具挑战的能效标准

动态功耗低至60μA/MHz!助力设备超长续航,首选国民技术低功耗MCU!