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ML4803IS-1 参数 Datasheet PDF下载

ML4803IS-1图片预览
型号: ML4803IS-1
PDF下载: 下载PDF文件 查看货源
内容描述: 8引脚PFC和PWM控制器组合 [8-Pin PFC and PWM Controller Combo]
分类和应用: 功率因数校正控制器
文件页数/大小: 13 页 / 185 K
品牌: MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
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February 1999
PRELIMINARY
ML4803
8-Pin PFC and PWM Controller Combo
GENERAL DESCRIPTION
The ML4803 is a space-saving controller for power factor
corrected, switched mode power supplies that offers very
low start-up and operating currents.
Power Factor Correction (PFC) offers the use of smaller,
lower cost bulk capacitors, reduces power line loading
and stress on the switching FETs, and results in a power
supply fully compliant to IEC1000-3-2 specifications. The
ML4803 includes circuits for the implementation of a
leading edge, average current “boost” type PFC and a
trailing edge, PWM.
The ML4803-1’s PFC and PWM operate at the same
frequency, 67kHz. The PFC frequency of the ML4803-2 is
automatically set at half that of the 134kHz PWM. This
higher frequency allows the user to design with smaller
PWM components while maintaining the optimum
operating frequency for the PFC. An overvoltage
comparator shuts down the PFC section in the event of a
sudden decrease in load. The PFC section also includes
peak current limiting for enhanced system reliability.
FEATURES
s
s
Internally synchronized PFC and PWM in one 8-pin IC
Patented one-pin voltage error amplifier with advanced
input current shaping technique
Peak or average current, continuous boost, leading
edge PFC (Input Current Shaping Technology)
High efficiency trailing-edge current mode PWM
Low supply currents; start-up: 150µA typ., operating:
2mA typ.
Synchronized leading and trailing edge modulation
Reduces ripple current in the storage capacitor
between the PFC and PWM sections
Overvoltage, UVLO, and brownout protection
PFC V
CC
OVP with PFC Soft Start
s
s
s
s
s
s
s
BLOCK DIAGRAM
7
VEAO
4
35µA
–1
7V
+
PFC OFF
VCC
17.5V
16.2V
+
REF
VCC OVP
COMP
VREF
GND
2
COMP
M3
M4
PFC
CONTROL
LOGIC
PFC OUT
1
M1
M2
R1
M7
C1
30pF
LEADING
EDGE PFC
ONE PIN ERROR AMPLIFIER
3
ISENSE
–4
+
+
PFC ILIMIT
VCC
COMP
SOFT START
TRAILING
EDGE PWM
–1V
PFC/PWM UVLO
OSCILLATOR
PFC – 67kHz
PWM – 134kHz
VREF
VDC
26k
DUTY CYCLE
LIMIT
5
PWM COMPARATOR
PWM
CONTROL
LOGIC
PWM OUT
8
40k
1.2V
6
ILIMIT
M6
COMP
+
COMP
+
1.5V
+
DC ILIMIT
1