– 39 –IC551 XC111256FTAEB
+
–
+
–
242322212019
VC VG
1
2
3
4
5
6
7
8
3PHASE
CONTROL
PRE
DRIVER
48
VC
VC VC
PRE
DRIVER
H-BRIDGE
CONTROL
VC
H-BRIDGE
CONTROL
VG
47 46 45 44 43 42 41 39 38 37
+
–
40
36
35
34
VC
PRE
DRIVER
VG
9
10
11
12
33
32
31
30
VC
VC
PRE
DRIVER
H-BRIDGE
CONTROL
VC
H-BRIDGE
CONTROL
VG
VC
PRE
DRIVER
VG
28
29
26
25
27
14 15 16 1713
BIAS
VC ROE
VG
18
VC
VI
UI
PWM
VM1
RO1
PGND1
FO1
VM12
RO2
PGND2
FO2
VM2
RI2
FI2
RI1
FI1
OE
VC
GND
VG
FI3
RI3
FI4
RI4
PWM24
FO4
PGND4
RO4
VM34
FO3
PGND3
RO3
VM3
CPWO
CPVO
CPUO
COM
CPWI
CPVI
CPUI
GNDW
WO
VMVW
VO
GNDUV
UO
VMU
WI
IC903 XC6383C601MR
1
2
3
CHIP
ENABLE
+
–
+
–
VREF
2STEP PFM CONTROL
OSC 100/180kHz
VLX LIMITER 5
4
VDD
CE
VOUT
NC VSS
LX
BUFFER
IC904, 907 XC6368B101MR
1
2
3
5
4
+
–+
–
PHASE
COMPENSATION
BUFFER,
DRIVER
PWM/PFM
CONTROLLER
REFERENCE VOLTAGE
WITH SOFT START,
CHIP ENABLE
RAMP WAVE
GENERATOR,
OSC
FB
VDD
CE
EXT
GND
ERROR AMP PWM
COMPARATOR