FA5558 Fuji Electric holdings CO.,Ltd, FA5558 Datasheet - Page 23

• Manufacturer Part Number: FA5558
• Description: Green Mode Pwm Ic
• Manufacturer: Fuji Electric holdings CO.,Ltd

(11) Output unit
The push/pull structure output circuit drives the MOSFET
directly. The peak output current of the OUT terminal is
0.5A (source) and 1.0A (sink) in the maximum absolute
ratings.
In a state in which the IC is stopped in the undervoltage
lockout circuit or operation is suspended in the latch mode,
or in an auto reset wait state by overload protection
function, the OUT terminal is brought into the Low level,
and the MOSFET is interrupted.
(12) Brown out (low AC input voltage
protection)
This IC integrates a brown out function that stops the
output pulse of the OUT terminal when the AC input
voltage decreases to protect the circuit.
Integration of a high withstand voltage resistor eliminates
the need of external parts.
Switching is started when the peak of the AC input voltage
to the VH terminal reaches the brown in threshold voltage
(104V typ). (See Fig.19)
When the input voltage decreases down to brown out
threshold voltage (99V typ) or lower, the output is stopped
after 50ms (typ) of delay time. (See Fig.20)
The brown out function is actuated after the UVLO is reset.
While switching operation is suspended by the brown out
function, the startup circuit is subjected to ON/OFF control
to maintain the VCC voltage within the 15.5V to 18V (typ)
range.
AN-025E Rev.0.1
December-2008
FA5558/87/88/89
FA5581/82/83/84
23
Brown OUT
Fig. 20 Conceptual diagram of brown in and brown
Brown IN
Diod brige
Secondary
Diod brige
Secondary
Half wave
Half wave
Fig. 19 Brown in and brown out detection circuit
MOS gate
MOS gate
Vo
Vo
Fuji Electric Device Technology
out operations
50ms Delay time
Brown-IN Vth
Rating Vo
Rating Vo
0
0
0
Brown-OUT Vth
0
0
0