HCD-MX500i/MX550i
46
– POWER Board –
IC601 MIP2F20MS1SO
CONSTANT
CURRENT
SOURCE
2
FB
1
VDD
4
VCC
5 DRAIN
8 SOURCE
7 SOURCE
3
CL
VCL
CLAMP CIRCUIT
(ILIMIT SETTING)
IN
ICL.LOW
VCL.OUT
ILIMIT VARIABLE
CIRCUIT
+
–
+
–
+
–
7.2V
+
–
2.4V
VCC UV
VCC OVP
OVERHEAT
PROTECTION
S
R
Q
Q
RESTARTING
TRIGGER
R
S
Q
Q
+
–
27%
22%
FOR LIGHT LOAD
DETECTION INTERMITTENT
OSCILLATION CONTROL
GENERATOR
CLOCK
12kHz
MAXDC
5.7V
5.0V
VDD UV
5.7V
REGULATOR
VDD CLAMP
CIRCUIT
6.6V
+
–
ILIMIT
CORRECTION
CIRCUIT
FOR
DRAIN CURRENT
DETECT
GATE DRIVER
POWER
MOSFET
AT TURNING ON
BLANKING PULSE
GENERATION CIRCUIT
IC904 SI-8001FFEK
IC905 SI-3010KFEK
IN
1
SW
2
SS
5
ADJ
4
LATCH
&
DRIVER
ERROR AMP
COMPARATOR
OSCILLATOR
RESET
OVERCURRENT
PROTECTION
THERMAL
PROTECTION
REFERENCE
VOLTAGE
GND
3
ON/OFF
SOFT
START
PREG
+
+
+
–
–
1
VC
TSD
2
VIN
3
GND
4
VOUT
5
ADJ
+
–
REF