LTC3520 Datasheet, PDF (7/24 Pages) Linear Technology – Synchronous 1A Buck-Boost and 600mA Buck Converters

TYPICAL PERFORMANCE CHARACTERISTICS
LTC3520
Buck-Boost Maximum
Output Current, PWM Mode
1800
1600
V_OUT = 3.3V
1400
1200
1000
V_OUT = 5V
800
600
400
200
0
2.2 2.7 3.2 3.7 4.2 4.7 5.2
V_IN (V)
3520 G16
Buck-Boost PWM Mode
Efficiency vs Frequency
100
L = 8.2µH COILCRAFT
MSS6132
95
L = 4.7µH COILCRAFT
MSS7341
90
L = 2.2µH
85
COILCRAFT
1812PS
80
75 ^VIN ^{= 3.6V}
V_OUT = 3.3V
I_LOAD = 200mA
70
0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
SWITCHING FREQUENCY (MHz)
3520 G18
Buck-Boost
Burst Mode Operation
Buck-Boost Maximum Output
Current, Burst Mode Operation
140
120
V_OUT = 3.3V
100
80
V_OUT = 5V
60
40
20
0
2.2 2.7 3.2 3.7 4.2 4.7 5.2
V_IN (V)
3520 G17
Buck Efficiency vs Frequency
100
95
L = 8.2µH
COILCRAFT
90 MSS6132
85
L = 4.7µH SUMIDA
CDRH3D16NP
L = 2.2µH
SUMIDA
CDRH3D16NP
80
75 ^VIN ^{= 2.5V}
V_OUT = 1.8V
I_LOAD = 100mA
70
0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
SWITCHING FREQUENCY (MHz)
3520 G19
Buck Burst Mode Operation
V_OUT
50mV/DIV
INDUCTOR
CURRENT
200mA/DIV
20µs/DIV
C_OUT = 22µF I_LOAD = 25mA
L = 4.7µH V_IN = 3.6V
3520 G21
BUCK V_OUT
50mV/DIV
INDUCTOR
CURRENT
200mA/DIV
V_IN = 3.6V
V_OUT = 1.8V
I_LOAD = 10mA
10µs/DIV
R_BURST = 249k
C_OUT = 10µF
3520 G22
3520f
7