Datasheet

LTC3522
4
3522fa
TYPICAL PERFORMANCE CHARACTERISTICS
Buck-Boost Effi ciency,
Li-Ion to 3.3V
Buck Effi ciency, Li-Ion to 2.5V
Buck Effi ciency, Li-Ion to 1.8V
Buck Burst Mode Threshold
Buck Switch R
DS(0N)
Switching Frequency vs
Temperature
LOAD CURRENT (mA)
1
0
EFFICIENCY (%)
POWER LOSS (mW)
20
30
40
50
60
70
10
100
3522 G01
80
90
100
0
20
40
60
80
100
120
140
160
10
1000
Burst Mode
OPERATION
Burst Mode
POWER LOSS
PWM Mode
V
IN
= 4.2V
V
IN
= 2.7V
L: COILCRAFT
MSS6132-4.7μH
LOAD CURRENT (mA)
1
0
EFFICIENCY (%)
POWER LOSS (mW)
20
30
40
50
60
70
10
100
3522 G02
80
90
100
0
20
40
80
60
100
120
140
160
10
1000
V
IN
= 3.7V
V
IN
= 4.2V
Burst Mode
OPERATION
Burst Mode
POWER LOSS
PWM Mode
L: COILCRAFT
MSS6132-8.2μH
LOAD CURRENT (mA)
1
0
EFFICIENCY (%)
POWER LOSS (mW)
20
30
40
50
60
70
10
100
3522 G03
80
90
100
0
20
40
60
80
100
120
140
160
10
1000
Burst Mode
OPERATION
Burst Mode
POWER LOSS
PWM Mode
V
IN
= 4.2V
V
IN
= 2.7V
L: COILCRAFT
MSS6132-8.2μH
Buck-Boost Switch R
DS(0N)
V
IN
(V)
2.4
0
LOAD CURRENT (mA)
5
15
20
25
50
35
3.4
4.4
4.9
3522 G04
10
40
45
30
2.9
3.9
5.4
V
OUT
= 1.2V
V
OUT
= 1.8V
V
OUT
= 2.5V
L = 4.7μH
TEMPERATURE (°C)
–40
R
DS(ON)
(mΩ)
200
250
300
120
3522 G05
150
100
0
0
40
80
–20
20
60
100
50
400
PMOS
(SWITCHES A AND D)
NMOS
(SWITCHES B AND C)
350
TEMPERATURE (°C)
–40
R
DS(ON)
(mΩ)
400
500
120
3522 G06
300
200
0
0
40
80
–20
20
60
100
100
600
PMOS
NMOS
TEMPERATURE (°C)
–50
–10
CHANGE FROM 25°C (%)
–8
–4
–2
0
10
4
–10
30
50
3522 G07
–6
6
8
2
–30 10
70
90
110
Switching Frequency vs V
IN
V
IN
(V)
2.5
–10
CHANGE FROM V
IN
= 3.6V (%)
–8
–4
–2
0
10
4
3.4
4.4
4.9
3522 G08
–6
6
8
2
2.9
3.9
5.4
(T
A
= 25°C unless otherwise noted)