長效行動電源的解決設計

2011/12
Power Management
E
T
Sean Hung
99
(wh/kg)
(NiCd)
(Ni-MH)
DC/DC
(Ni-MH)
DC/DC
DC/DC
DC/DC
(Switch Frequency)
RDS(ON)
DC/DC
Power Management
2011/12
E
T
1
100
2
DC/DC
1
(Buck Convector)
DC/DC
(Boost Convector)
DC/DC
AIC2341
(Buck-Boost Convector)
2
3.3V
0V
(Buck Circuit)
(Boost
Circuit)
2.5MHZ
(Switch Frequency)
1A
(Output
Current)
(1)
(2)
2011/12
Power Management
(5)
(Switch Frequency, fsw)
2.5MHz
(6)
(Duty Cycle, D)
(Inductor Current Ripple,
IL)
E
T
(1)
3
1
(2)
101
PCB Layout
(Saturation
Current)
(3)
IC
(4)
(EMI)
(Maximum Peak Current of
(Power GND)
Inductor)
(GND)
IC
(3)
(MODE)
(4)
(Jumper-SW2)
(5)
(Output Ripple,
(5)
(Pulse Skip Modulation, PSM)
(6)
(Pulse Width
VOUT)
Modulation, PWM)
(6)
(Jumper-SW1)
(Enable)
(Switch Frequency, fsw)
(Duty Cycle, D)
PCB Layout
2.5MHz
(Inductor, L)
(Output
capacitance, COUT)
X5R
X7R
(ESR)
3
PCB Layout
Power Management
3
1
2011/12
(BOM)
E
T
102
5 (Buck-Boost)
4 (Buck)
(VIN=3.3V,VOUT=3.3V/100mA)
(VIN=4.2V,VOUT=3.3V/100mA)
4.2V
4
IC
4.2V
SW1
6 (Boost)
3.3V
(VIN=2.5V,VOUT=3.3V/100mA)
SW2
DC
3.3V
SW1
SW1
DC
SW2
90.2%
20mV
89.6%
3.3V
5
50mV
(MODE)
IC
3.3V
SW1
(Jumper-SW2)
GND
(Pulse Skip Modulation, PSM)
SW2
92.3%
7
50mV
2.5V
6
IC
2.5V
SW2
2011/12
7 (Power Save Mode, PSM)
Power Management
E
T
(VIN=3.3V,VOUT=3.3V/10mA)
8 AIC234
103
AIC2341
3.3V
BUCK
7
BOOST
8
BUCK-BOOST
8
D(t)
D(t)
DC/DC
Vg
?
L
L
R
C
R
D(t)
R
D(t)
R