ML4803IP-1 Micro Linear, ML4803IP-1 Datasheet - Page 10

• Manufacturer Part Number: ML4803IP-1
• Description: 8-Pin PFC and PWM Controller Combo
• Manufacturer: Micro Linear

ML4803
inductor. The V
voltage exceeds 16V, and terminates the PFC output drive
while disabling the VEAO current sink. Once the VEAO
current sink is disabled, the VEAO voltage will charge
unabated, except for a diode clamp to V
PFC pulse width. Once the V
below 16.2V the VEAO sink will be enabled, discharging
external VEAO compensation components until the steady
state voltage is reached. Given that 15V on V
corresponds to 400V on the PFC output, 16V on V
corresponds to an OVP level of 426V.
10
TYPICAL APPLICATIONS
CC
OVP comparator senses when this
C ZERO
R COMP
CC
V OUT = 400V
rail has decreased to
C COMP
RP
Figure 10. Typical Peak Current Mode Waveforms
(Continued)
CC
, reducing the
4
3
Figure 11. ML4803 PFC Control
VEAO
I SENSE
CC
CC
35µA
COMPONENT REDUCTION
Components associated with the V
typical PFC controller such as the ML4824 have been
eliminated. The PFC power limit and bandwidth does vary
with line voltage. Double the power can be delivered from
a 220 V AC line versus a 110 V AC line. Since this is a
combination PFC/PWM, the power to the load is limited
by the PWM stage.
February 1999
R1
V ISENSE
OUTPUT
V C1 RAMP
DRIVE
GATE
5V
–4
C 1
30pF
V I SENSE
V C1
+
–
COMP
RMS
GATE
OUTPUT
and I
RMS
pins of a