ML4826
TYPICAL PERFORMANCE CHARACTERISTICS
250
250
200
200
150
150
100
100
50
50
0
0
1
2
3
4
5
VFB (V)
Voltage Error Amplifier (VEA) Transconductance (gm)
400
0
-500
0
500
IEA Input Voltage (mV)
Current Error Amplifier (IEA) Transconductance (gm)
300
200
100
0
0
1
2
3
4
5
VRMS (mV)
Variable Gain Control Transfer Characteristic
20
VEAO
1
IEAO
VFB
19
VEA
-
3.5kΩ IEA
-
2.5V +
+
IAC
+
-
2
VRMS
4
ISENSE
GAIN
MODULATOR
8V
3.5kΩ
3
RAMP 1
8
RTCT
7
OSCILLATOR
x2
2.7V
OVP
+
-
-1V +
-
PFC ILIMIT
VCCZ
13.5V
17
VCC
7.5V
REFERENCE
VREF
18
SQ
RQ
SQ
RQ
PFC OUT
15
VCCZ
Figure 1. PFC Section Block Diagram.
UVLO
6