参数资料
型号: L6599D
厂商: STMICROELECTRONICS
元件分类: 稳压器
英文描述: 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
封装: LEAD FREE, SOP-16
文件页数: 10/36页
文件大小: 636K
代理商: L6599D
Application information
L6599
18/36
7.2
Operation at no load or very light load
When the resonant half-bridge is lightly loaded or unloaded at all, its switching frequency will
be at its maximum value. To keep the output voltage under control in these conditions and to
avoid losing soft-switching, there must be some significant residual current flowing through
the transformer's magnetizing inductance. This current, however, produces some
associated losses that prevent converter's no-load consumption from achieving very low
values.
To overcome this issue, the L6599 enables the designer to make the converter operate
intermittently (burst-mode operation), with a series of a few switching cycles spaced out by
long idle periods where both MOSFETs are in OFF-state, so that the average switching
frequency can be substantially reduced. As a result, the average value of the residual
magnetizing current and the associated losses will be considerably cut down, thus
facilitating the converter to comply with energy saving recommendations.
The device can be operated in burst-mode by using pin 5 (STBY): if the voltage applied to
this pin falls below 1.25 V the IC will enter an idle state where both gate-drive outputs are
low, the oscillator is stopped, the soft-start capacitor CSS keeps its charge and only the 2 V
reference at RFmin pin stays alive to minimize IC's consumption and VCC capacitor's
discharge. The IC will resume normal operation as the voltage on the pin exceeds 1.25 V by
50 mV.
To implement burst-mode operation the voltage applied to the STBY pin needs to be related
to the feedback loop. Figure 24 shows the simplest implementation, suitable with a narrow
input voltage range (e.g. when there is a PFC front-end).
Figure 24. Burst-mode implementation: narrow input voltage range
Figure 25. Burst-mode implementation: wide input voltage range
L6599
STBY
4
5
RFmin
RFmin
RFmax
RFmin
RFmax
L6599
STBY
4
5
RFmin
RFmin
RFmax
7
LINE
RA
B+
RB
RC
RD
RA + RB >> RC
RC
RD
相关PDF资料
PDF描述
L6599N 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDIP16
L6599TR 0.8 A SWITCHING CONTROLLER, 500 kHz SWITCHING FREQ-MAX, PDSO16
L6610D 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO24
L6610N 6-CHANNEL POWER SUPPLY SUPPORT CKT, PDIP24
L6611DTRT POWER SUPPLY SUPPORT CKT, PDSO20
相关代理商/技术参数
参数描述
L6599DTR 功能描述:软开关 PWM 控制器 Hi Vltg resonant Controller RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
L6599N 功能描述:软开关 PWM 控制器 Hi Vltg resonant Controller RoHS:否 制造商:Fairchild Semiconductor 输出端数量: 输出电流: 开关频率: 工作电源电压:30 V 电源电流: 最大工作温度:+ 105 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8 封装:Reel
L6599NR 功能描述:电压模式 PWM 控制器 HV resonant CNTRL RoHS:否 制造商:Texas Instruments 输出端数量:1 拓扑结构:Buck 输出电压:34 V 输出电流: 开关频率: 工作电源电压:4.5 V to 5.5 V 电源电流:600 uA 最大工作温度:+ 125 C 最小工作温度:- 40 C 封装 / 箱体:WSON-8 封装:Reel
L6599TR 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:High-voltage resonant controller
L65B 制造商:Electro-Mech 功能描述: