LTC3522_15 Datasheet, PDF (4/20 Pages) Linear Technology – Synchronous 400mA Buck-Boost and 200mA Buck Converters

LTC3522
TYPICAL PERFORMANCE CHARACTERISTICS (T_A = 25°C unless otherwise noted)
Buck-Boost Efficiency,
Li-Ion to 3.3V
100
160
90 ^{Burst Mode}
140
OPERATION
80
120
70
60
100
PWM Mode
50
80
40
30
20
10
0
1
Burst Mode
POWER LOSS
10
60
V_IN = 4.2V 40
V_IN = 2.7V
L: COILCRAFT ²⁰
MSS6132-4.7μH
0
100
1000
LOAD CURRENT (mA)
3522 G01
Buck Efficiency, Li-Ion to 2.5V
100
160
Burst Mode
90 OPERATION
140
80
120
70
PWM Mode
60
100
50
80
40
Burst Mode
POWER LOSS
60
30
V_IN = 3.7V
V_IN = 4.2V
40
20 _{L: COILCRAFT}
10 ^{MSS6132-8.2μH}
20
0
0
1
10
100
1000
LOAD CURRENT (mA)
3522 G02
Buck Efficiency, Li-Ion to 1.8V
100 _{Burst Mode}
160
90 OPERATION
140
80
120
70
PWM Mode
60
100
50
80
40
Burst Mode
POWER LOSS
60
30
V_IN = 4.2V
V_IN = 2.7V
40
20 _{L: COILCRAFT}
10 MSS6132-8.2μH
20
0
0
1
10
100
1000
LOAD CURRENT (mA)
3522 G03
Buck Burst Mode Threshold
50
L = 4.7μH
45
40
V_OUT = 1.2V
35
30
V_OUT = 1.8V
25
20
15
V_OUT = 2.5V
10
5
0
2.4 2.9 3.4 3.9 4.4 4.9 5.4
V_IN (V)
3522 G04
Buck-Boost Switch R_DS(0N)
400
350
PMOS
(SWITCHES A AND D)
300
250
200
NMOS
(SWITCHES B AND C)
150
100
50
0
–40 –20
0 20 40 60 80 100 120
TEMPERATURE (°C)
3522 G05
Buck Switch R_DS(0N)
600
500
PMOS
400
NMOS
300
200
100
0
–40 –20
0 20 40 60 80 100 120
TEMPERATURE (°C)
3522 G06
Switching Frequency vs
Temperature
10
8
6
4
2
0
–2
–4
–6
–8
–10
–50 –30 –10 10 30 50 70 90 110
TEMPERATURE (°C)
3522 G07
Switching Frequency vs V_IN
10
8
6
4
2
0
–2
–4
–6
–8
–10
2.5 2.9 3.4 3.9 4.4 4.9 5.4
V_IN (V)
3522 G08
3522fa
4