参数资料
| 型号： | RDK-236 |
| 厂商： | Power Integrations |
| 文件页数： | 5/30页 |
| 文件大小： | 0K |
| 描述： | KIT REF DESIGN PFS714EG |
| 标准包装： | 1 |
| 系列： | HiperPFS™ |
| 主要目的： | 电源管理，功率因数校正 |
| 嵌入式： | 否 |
| 已用 IC / 零件： | PFS714EG |
| 主要属性： | 347W，370 ~ 390V 输出，90 ~ 264VAC 输入 |
| 已供物品： | 板 |
| 其它名称： | 596-1418 |
第1页第2页第3页第4页当前第5页第6页第7页第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页
PFS704-729EG
Functional Description
The HiperPFS is a variable switching frequency boost PFC
V E
solution. More specifically, it employs a constant amp-second
on-time and constant volt-second off-time control algorithm.
This algorithm is used to regulate the output voltage and shape
the input current to comply with regulatory harmonic current
limits (high power factor). Integrating the switch current and
controlling it to have a constant amp-sec product over the
on-time of the switch allows the average input current to follow
the input voltage. Integrating the difference between the output
and input voltage maintains a constant volt-second balance
dictated by the electro-magnetic properties of the boost inductor
and thus regulates the output voltage and power.
Latch
RESET
Latch
SET
Gate
Drive (Q)
Maximum
ON-time
Minimum
OFF-time
V OFF
I S dt
(V OUT -V IN )dt
Timing
Supervisor
More specifically, the control technique sets constant volt-
seconds for the off-time (t OFF ). The off-time is controlled such
that:
Figure 4.
Idealized Converter Waveforms.
(1)
Since the volt-seconds during the on-time must equal the
volt-seconds during the off-time, to maintain flux equilibrium in
the PFC choke, the on-time (t ON ) is controlled such that:
(2)
The controller also sets a constant value of charge during each
on-cycle of the power MOSFET. The charge per cycle is varied
gradually over many switching cycles in response to load
changes so it can be regarded as substantially constant for a
half line cycle. With this constant charge (or amp-second)
control, the following relationship is therefore also true:
cycle on-time. Internally the difference between the input and
output voltage is derived and the resultant is scaled, integrated,
and compared to a voltage reference (V OFF ) to determine the
cycle off-time. Careful selection of the internal scaling factors
produce input current waveforms with very low distortion and
high power factor.
The input voltage is internally synthesized using the switch duty
cycle and a 7 kHz low pass filter. This synthesized input voltage
representation is subtracted from a fixed reference voltage (6 V)
to derive a current source proportional to (V O -V IN ). Please refer to
Figure 3.
Line Feed-Forward Scaling Factor (M ON )
The VOLTAGE MONITOR (V) pin current is used internally to
Substituting t ON from (2) into (3) gives:
(3)
(4)
derive the peak of the input line voltage which is used to scale
the gain of the current sense signal through the M ON variable.
This contribution is required to reduce the dynamic range of the
control feedback signal as well maintain a constant loop gain
over the operating input line range. This line-sense feed-
forward gain adjustment is proportional to the square of the
The relationship of (4) demonstrates that by controlling a constant
amp-second on-time and constant volt-second off-time, the input
current I IN is proportional to the input voltage V IN , therefore
providing the fundamental requirement of power factor correction.
This control produces a continuous mode power switch current
waveform that varies both in frequency and peak current value
across a line half-cycle to produce an input current proportional
to the input voltage.
Control Engine
The controller features a low bandwidth error-amplifier which
connects its non-inverting terminal to an internal voltage
reference of 6 V. The inverting terminal of the error-amplifier is
available on the external FEEDBACK pin which connects to the
external feedback resistor divider, transient load speed-up and
compensation networks to regulate the output voltage.
The internal sense-FET switch current is integrated and scaled
by the input voltage peak detector current sense gain (M ON ) and
compared with the error-amplifier signal (V E ) to determine the
www.powerint.com
peak rectified AC line voltage and is adjusted as a function of V
pin current. The line-sense feed-forward gain is also important
in providing a switch power limit over the input line range.
Besides modifying brown- in/out thresholds, the V pin resistor
also affects power limit of the device
This characteristic is optimized to maintain a relatively constant
internal error-voltage level at full load from an input line of 100
to 230 VAC input (PFS704-716).
Beyond the specified peak power rating of the device, the
internal power limit feature will regulate the output voltage
below the set regulation threshold as a function of output
overload beyond the peak power rating. Figure 5 illustrates the
typical regulation characteristic as function of load.
Soft-Start with Pin-to-Pin Short-Circuit Protection
Since the FEEDBACK pin is the interface for output voltage
regulation (resistor voltage divider to output voltage) as well as
loop compensation (series RC), the typical application circuit of
the HiperPFS requires an external transistor network to overcome
the inherently slow feedback loop response. Specifically, an
5
Rev. F 12/12
相关PDF资料 |
PDF描述 |
|---|---|
| RECE-20279-001E-01 | RCPT IPEX MHF |
| RF2594-000 | BD540-30 |
| RF2873-000 | POLYSWITCH 1.25A RESET FUSE RAD |
| RGEF1000-1 | POLYSWITCH PTC RESET 10A HOLD |
| RGEF1000-2 | POLYSWITCH PTC RESET 10A HLD T/R |
相关代理商/技术参数 |
参数描述 |
|---|---|
| RDK-239 | 功能描述:LED 照明开发工具 HV 150W RESONANT CONVERTER KIT RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: |
| RDK-242 | 功能描述:电源管理IC开发工具 TOPSwitch-JX REF. DESIGN KIT RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| RDK-248 | 功能描述:LED 照明开发工具 UNIVERSAL PFC 180W HiperPFS KIT RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: |
| RDK-249 | 功能描述:线性和开关式电源 HiperTFS Ref Des Kit 14.W Stby, 300W PS RoHS:否 制造商:TDK-Lambda 产品:Switching Supplies 开放式框架/封闭式:Enclosed 输出功率额定值:800 W 输入电压:85 VAC to 265 VAC 输出端数量:1 输出电压（通道 1）:20 V 输出电流（通道 1）:40 A 商用/医用: 输出电压（通道 2）: 输出电流（通道 2）: 安装风格:Rack 长度: 宽度: 高度: |
| RDK-251 | 功能描述:LED 照明开发工具 LinkSwitch-PL Ref Des Kit, 5W Dim RoHS:否 制造商:Fairchild Semiconductor 产品:Evaluation Kits 用于:FL7732 核心: 电源电压:120V 系列: 封装: |
发布紧急采购，3分钟左右您将得到回复。