- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄377970 > ML4800 (Fairchild Semiconductor Corporation) Power Factor Correction and PWM Controller Combo(功率因數(shù)校正器和PWM控制器組合芯片) PDF資料下載
參數(shù)資料
| 型號(hào)： | ML4800 |
| 廠商： | Fairchild Semiconductor Corporation |
| 元件分類： | 基準(zhǔn)電壓源/電流源 |
| 英文描述： | Power Factor Correction and PWM Controller Combo(功率因數(shù)校正器和PWM控制器組合芯片) |
| 中文描述： | 功率因數(shù)校正和PWM控制器組合（功率因數(shù)校正器和脈寬調(diào)制控制器組合芯片） |
| 文件頁數(shù)： | 11/14頁 |
| 文件大?。?/td> | 270K |
| 代理商： | ML4800 |
ML4800
FUNCTIONAL DESCRIPTION
(Continued)
C
t
A
V
SS
DELAY
=
×
25
125
.
μ
(6)
where C
SS
is the required soft start capacitance, and t
DELAY
is the desired start-up delay.
It is important that the time constant of the PWM soft-start
allow the PFC time to generate sufficient output power for
the PWM section. The PWM start-up delay should be at
least 5ms.
Solving for the minimum value of C
SS
:
C
ms
5
A
V
nF
SS
=
×
=
25
125
.
100
μ
(6a)
Generating V
CC
The ML4800 is a voltage-fed part. It requires an external
15V, ±10% (or better) shunt voltage regulator, or some
other V
CC
regulator, to regulate the voltage supplied to the
part at 15V nominal. This allows low power dissipation
while at the same time delivering 13V nominal gate drive
at the PWM OUT and PFC OUT outputs. If using a Zener
diode for this function, it is important to limit the current
through the Zener to avoid overheating or destroying it.
This can be easily done with a single resistor in series with
the Vcc pin, returned to a bias supply of typically 18V to
20V. The resistor’s value must be chosen to meet the
operating current requirement of the ML4800 itself
(8.5mA, max.) plus the current required by the two gate
driver outputs.
EXAMPLE:
With a V
BIAS
of 20V, a V
CC
of 15V and the ML4800 driving
a total gate charge of 90nC at 100kHz (e.g., 1 IRF840
MOSFET and 2 IRF820 MOSFETs), the gate driver current
required is:
I
kHz
nC
mA
9
GATEDRIVE
=
×
=
100
90
(7)
R
V
I
CC
V
+
I
I
BIAS
BIAS
CC
G
z
=
+
(8)
R
V
9
V
+
mA
6
mA
mA
5
BIAS
=
+
=
20
15
250
Choose R
BIAS
= 240
W.
The ML4800 should be locally bypassed with a 1.0μF
ceramic capacitor. In most applications, an electrolytic
capacitor of between 47μF and 220μF is also required
across the part, both for filtering and as part of the start-up
bootstrap circuitry.
RAMP
VEAO
TIME
VSW1
TIME
REF
EA
–
+
–
+
OSC
DFF
R
D
Q
Q
CLK
U1
RAMP
CLK
U4
U3
C1
RL
I4
SW2
SW1
+
DC
I1
I2
I3
VIN
L1
U2
Figure 4. Typical Trailing Edge Control Scheme
REV. 1.0 10/10/2000
11
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ML4801CP | Variable Feedforward PFC/PWM Controller Combo |
| ML4801CS | Variable Feedforward PFC/PWM Controller Combo |
| ML4801IP | Variable Feedforward PFC/PWM Controller Combo |
| ML4801IS | Variable Feedforward PFC/PWM Controller Combo |
| ML4801 | Variable Feedforward PFC/PWM Controller Combo(前饋可變PFC/PWM控制器組合芯片) |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ML4800_0109 | 制造商:FAIRCHILD 制造商全稱:Fairchild Semiconductor 功能描述:Power Factor Correction and PWM Controller Combo |
| ML4800CP | 功能描述:功率因數(shù)校正 IC PFC Controller PWM Combo RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel |
| ML4800CP | 制造商:Fairchild Semiconductor Corporation 功能描述:IC PFC/PWM COMBO 4800 DIP16 |
| ML4800CP_NL | 功能描述:功率因數(shù)校正 IC Power Factor PWM Contrl 0.2mA 81KHz RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel |
| ML4800CP_Q | 功能描述:功率因數(shù)校正 IC PFC Controller PWM Combo RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel |
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。
