- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄68995 > FSGM0465RWDTU (FAIRCHILD SEMICONDUCTOR CORP) SWITCHING CONTROLLER, ZFM6 PDF資料下載
參數(shù)資料
| 型號： | FSGM0465RWDTU |
| 廠商： | FAIRCHILD SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | SWITCHING CONTROLLER, ZFM6 |
| 封裝： | LEAD FREE, TO-220, 6 PIN |
| 文件頁數(shù)： | 18/18頁 |
| 文件大?。?/td> | 903K |
| 代理商： | FSGM0465RWDTU |
2009 Fairchild Semiconductor Corporation
www.fairchildsemi.com
FSGM0465R Rev. 1.0.2
9
FSGM
0465R
—
Green-
M
ode
Fairchild
Power
Swit
ch
(
F
PS)
Functional Description
1. Startup: At startup, an internal high-voltage current
source supplies the internal bias and charges the
external capacitor (CVcc) connected to the VCC pin, as
illustrated in Figure 17. When VCC reaches 12V, the
FSGM0465R begins switching and the internal high-
voltage current source is disabled. The FSGM0465R
continues normal switching operation and the power is
supplied from the auxiliary transformer winding unless
VCC goes below the stop voltage of 7.5V.
Figure 17. Startup Block
2. Soft-Start: The FSGM0465R has an internal soft-
start circuit that increases PWM comparator inverting
input voltage, together with the SenseFET current,
slowly after it starts. The typical soft-start time is 15ms.
The pulse width to the power switching device is
progressively increased to establish the correct working
conditions for transformers, inductors, and capacitors.
The voltage on the output capacitors is progressively
increased to smoothly establish the required output
voltage. This helps prevent transformer saturation and
reduces stress on the secondary diode during startup.
3. Feedback Control: This device employs current-
mode control, as shown in Figure 18. An opto-coupler
(such as the FOD817) and shunt regulator (such as the
KA431) are typically used to implement the feedback
network. Comparing the feedback voltage with the
voltage across the RSENSE resistor makes it possible to
control the switching duty cycle. When the reference pin
voltage of the shunt regulator exceeds the internal
reference voltage of 2.5V, the opto-coupler LED current
increases, pulling down the feedback voltage and
reducing drain current. This typically occurs when the
input voltage is increased or the output load is decreased.
3.1 Pulse-by-Pulse Current Limit: Because current-
mode control is employed, the peak current through
the SenseFET is limited by the inverting input of PWM
comparator (VFB*), as shown in Figure 18. Assuming
that the 210μA current source flows only through the
internal resistor (3R + R =11.6k), the cathode
voltage of diode D2 is about 2.4V. Since D1 is
blocked when the feedback voltage (VFB) exceeds
2.4V, the maximum voltage of the cathode of D2 is
clamped at this voltage. Therefore, the peak value of
the current through the SenseFET is limited.
3.2 Leading-Edge Blanking (LEB): At the instant the
internal SenseFET is turned on, a high-current spike
usually occurs through the SenseFET, caused by
primary-side capacitance and secondary-side rectifier
reverse recovery. Excessive voltage across the
RSENSE resistor leads to incorrect feedback operation
in the current mode PWM control. To counter this
effect, the FSGM0465R employs a leading-edge
blanking (LEB) circuit. This circuit inhibits the PWM
comparator for tLEB (300ns) after the SenseFET is
turned on.
Figure 18. Pulse Width Modulation Circuit
相關PDF資料 |
PDF描述 |
|---|---|
| FSL106MR | 0.62 A SWITCHING CONTROLLER, 73 kHz SWITCHING FREQ-MAX, PDIP8 |
| FSL116HR | 1.24 A SWITCHING CONTROLLER, 110 kHz SWITCHING FREQ-MAX, DIP8 |
| FSL126HR | 1.68 A SWITCHING CONTROLLER, 110 kHz SWITCHING FREQ-MAX, PDIP8 |
| FSL126MR | 8 A SWITCHING CONTROLLER, 73 kHz SWITCHING FREQ-MAX, PDIP8 |
| FSL136HR | 2.41 A SWITCHING CONTROLLER, 110 kHz SWITCHING FREQ-MAX, PDIP8 |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| FSGM0565R | 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:Green-Mode Fairchild Power Switch (FPS?) |
| FSGM0565RB | 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:Green-Mode Fairchild Power Switch |
| FSGM0565RBLDTU | 功能描述:電源開關 IC - 配電 SMPS PWR SW, 5A 650V RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻（最大值）:85 mOhms 開啟時間（最大值）:400 us 關閉時間（最大值）:20 us 工作電源電壓:3.2 V to 6.5 V 電源電流（最大值）: 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:SOT-23-5 |
| FSGM0565RBUDTU | 功能描述:電源開關 IC - 配電 SMPS PWR SW, 5A 650V RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻（最大值）:85 mOhms 開啟時間（最大值）:400 us 關閉時間（最大值）:20 us 工作電源電壓:3.2 V to 6.5 V 電源電流（最大值）: 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:SOT-23-5 |
| FSGM0565RBWDTU | 功能描述:電源開關 IC - 配電 SMPS PWR SW, 5A 650V RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻（最大值）:85 mOhms 開啟時間（最大值）:400 us 關閉時間（最大值）:20 us 工作電源電壓:3.2 V to 6.5 V 電源電流（最大值）: 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:SOT-23-5 |
發(fā)布緊急采購，3分鐘左右您將得到回復。