전자부품 데이터시트 검색엔진
  Korean  ▼
ALLDATASHEET.CO.KR

X  

ML4805CP 데이터시트(PDF) 10 Page - Micro Linear Corporation

부품명 ML4805CP
상세설명  Variable Feedforward PFC/PWM Controller Combo
Download  13 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
제조업체  MICRO-LINEAR [Micro Linear Corporation]
홈페이지  http://www.microlinear.com
Logo MICRO-LINEAR - Micro Linear Corporation

ML4805CP 데이터시트(HTML) 10 Page - Micro Linear Corporation

Back Button ML4805CP Datasheet HTML 5Page - Micro Linear Corporation ML4805CP Datasheet HTML 6Page - Micro Linear Corporation ML4805CP Datasheet HTML 7Page - Micro Linear Corporation ML4805CP Datasheet HTML 8Page - Micro Linear Corporation ML4805CP Datasheet HTML 9Page - Micro Linear Corporation ML4805CP Datasheet HTML 10Page - Micro Linear Corporation ML4805CP Datasheet HTML 11Page - Micro Linear Corporation ML4805CP Datasheet HTML 12Page - Micro Linear Corporation ML4805CP Datasheet HTML 13Page - Micro Linear Corporation  
Zoom Inzoom in Zoom Outzoom out
 10 / 13 page
background image
ML4805
10
Generating VCC
The ML4805 is a voltage-fed part. It requires an external
15V±10% or better Zener shunt voltage regulator, or some
other controlled supply, to regulate the voltage supplied
to the part at 15V nominal. This allows a low power
dissipation while at the same time delivering 13V
nominal of gate drive at the PWM OUT and PFC OUT
outputs. If using a Zener diode, 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 ML4805
itself (8.5mA max.) plus the current required by the two
gate driver outputs.
EXAMPLE:
With a VBIAS of 20V, a VCC limit of 16.5V (max) and
driving a total gate charge of 110nC at 100kHz (1 IRF840
MOSFET and 2 IRF830 MOSFETs), the gate driver current
required is:
IkHz
nC
mA
GATEDRIVE
=
100
110
11
R
VV
mA
mA
BIAS =
-
+
=
20
165
75
11
180
.
.
The ML4805 should be locally bypassed with a 10nF and
a 1
µF ceramic capacitor. In most applications, an
electrolytic capacitor of between 100
µF and 330µF is also
required across the part, both for filtering and as part of
the start-up bootstrap circuitry.
LEADING/TRAILING MODULATION
Conventional Pulse Width Modulation (PWM) techniques
employ trailing edge modulation in which the switch will
turn on right after the trailing edge of the system clock.
The error amplifier output voltage is then compared with
the modulating ramp. When the modulating ramp reaches
the level of the error amplifier output voltage, the switch
will be turned OFF. When the switch is ON, the inductor
current will ramp up. The effective duty cycle of the
trailing edge modulation is determined during the ON
time of the switch. Figure 3 shows a typical trailing edge
control scheme.
In the case of leading edge modulation, the switch is
turned OFF right at the leading edge of the system clock.
When the modulating ramp reaches the level of the error
amplifier output voltage, the switch will be turned ON.
The effective duty-cycle of the leading edge modulation
is determined during the OFF time of the switch. Figure 4
shows a leading edge control scheme.
One of the advantages of this control technique is that it
requires only one system clock. Switch 1 (SW1) turns off
and switch 2 (SW2) turns on at the same instant to
minimize the momentary “no-load” period, thus lowering
ripple voltage generated by the switching action. With
such synchronized switching, the ripple voltage of the
first stage is reduced. Calculation and evaluation have
shown that the 120Hz component of the PFC’s output
ripple voltage can be reduced by as much as 30% using
this method.
FUNCTIONAL DESCRIPTION (Continued)
Figure 4. Leading/Trailing Edge Control Scheme
Figure 3. Typical Trailing Edge Control Scheme
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
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
VEAO
CMP
U2
RAMP
VEAO
TIME
VSW1
TIME


유사한 부품 번호 - ML4805CP

제조업체부품명데이터시트상세설명
logo
Fairchild Semiconductor
ML4805CP FAIRCHILD-ML4805CP Datasheet
125Kb / 13P
   Variable Feedforward PFC/PWM Controller Combo
More results

유사한 설명 - ML4805CP

제조업체부품명데이터시트상세설명
logo
Fairchild Semiconductor
ML4805 FAIRCHILD-ML4805 Datasheet
125Kb / 13P
   Variable Feedforward PFC/PWM Controller Combo
ML4801 FAIRCHILD-ML4801 Datasheet
160Kb / 14P
   Variable Feedforward PFC/PWM Controller Combo
logo
Micro Linear Corporatio...
ML4841 MICRO-LINEAR-ML4841 Datasheet
282Kb / 15P
   Variable Feedforward PFC/PWM Controller Combo
ML4801 MICRO-LINEAR-ML4801 Datasheet
248Kb / 14P
   Variable Feedforward PFC/PWM Controller Combo
logo
Fairchild Semiconductor
ML4841 FAIRCHILD-ML4841 Datasheet
129Kb / 15P
   Variable Feedforward PFC/PWM Controller Combo
logo
Champion Microelectroni...
CM6800T CHAMP-CM6800T Datasheet
852Kb / 27P
   EPA/85 PFCPWM COMBO CONTROLLER
CM6903 CHAMP-CM6903 Datasheet
257Kb / 14P
   Low Pin Count PFC/PWM Controller Combo
logo
Fairchild Semiconductor
FAN4803CP2 FAIRCHILD-FAN4803CP2 Datasheet
116Kb / 12P
   8-Pin PFC and PWM Controller Combo
FAN4803CP1 FAIRCHILD-FAN4803CP1 Datasheet
109Kb / 12P
   8-Pin PFC and PWM Controller Combo
ML4802 FAIRCHILD-ML4802 Datasheet
285Kb / 15P
   PFC/PWM Controller Combo with Green Mode
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13


데이터시트 다운로드

Go To PDF Page


링크 URL




개인정보취급방침
ALLDATASHEET.CO.KR
ALLDATASHEET 가 귀하에 도움이 되셨나요?  [ DONATE ] 

Alldatasheet는?   |   광고문의   |   운영자에게 연락하기   |   개인정보취급방침   |   링크교환   |   제조사별 검색
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com