ML4821
OFF-LINE START-UP AND BIAS SUPPLY GENERATION
The circuit in Figure 11 supplies V power to the
CC
ML4821. Start-up current is delivered via R10. The IC
starts when V reaches 15.5V. After that time running
CC
power is delivered through the tap on L1. The
configuration shown delivers a voltage proportional to the
PFC output bus voltage.
R10
TO B+
39kΩ
2W
TO IC
PIN 15
L1
1µF
1µF
1000µF
N
N
S
P
N
V
OUT
P
≈
N
14V
S
Figure 11. Bias and Start-up Circuit.
9
Micro Linear