ltc3521fe Linear Technology Corporation, ltc3521fe Datasheet - Page 4

• Manufacturer Part Number: ltc3521fe
• Description: Ltc3521 Wide Vin, 1a Buck-boost Dc/dc And Dual 600ma Buck Dc/dc Converters Features
• Manufacturer: Linear Technology Corporation

LTC3521
Typical perForMance characTerisTics

160
120
100
140
80
60
40
20
0
–40
Buck-Boost Switches R
V
V
IN
OUT1
–20
= 3.6V
= 3.3V
0
TEMPERATURE (°C)
20
100
100
(SWITCHES A AND D)
(SWITCHES B AND C)
90
80
70
60
50
40
30
20
90
80
70
60
50
40
30
20
10
10
0
0
0.1
0.1
40
Buck Efficiency, Li-Ion to 1.8V
Buck-Boost Efficiency,
Li-Ion to 3.3V
OPERATION
OPERATION
Burst Mode
Burst Mode
PMOS
NMOS
60
V
V
V
V
IN
IN
IN
IN
DS(ON)
= 2.7V
= 4.2V
= 2.7V
= 4.2V
80
1
1
LOAD CURRENT (mA)
LOAD CURRENT (mA)
100
3521 G05
120
PWM MODE
POWER LOSS
10
10
Burst Mode
Burst Mode
POWER LOSS
PWM MODE
100
100
350
300
250
200
150
100
50
0
–40
Buck Switches R
V
IN
3521 G01
3521 G03
1000
1000
–20
= 3.6V
140
120
100
80
60
40
20
140
120
100
80
60
40
20
0
0
0
TEMPERATURE (°C)
20
NMOS
PMOS
40
DS(ON)
60
100
20
90
80
70
60
50
40
30
20
10
60
50
40
30
10
80
0
0
0.1
1.5
Buck Efficiency, Li-Ion to 2.5V
Buck Burst Mode Current Threshold
100
V
T
V
3521 G06
OUT
A
OUT
2
V
V
120
IN
IN
= 25°C, unless otherwise noted.
OPERATION
V
Burst Mode
= 1.8V
OUT
= 3.6V
= 4.2V
= 2.5V
2.5
1
LOAD CURRENT (mA)
= 1.2V
3
V
–0.2
–0.4
–0.6
–0.8
–1.0
IN
3.5
POWER LOSS
10
1.0
0.8
0.6
0.4
0.2
(V)
0
Burst Mode
–50
Switching Frequency
vs Temperature
4
–30
PWM MODE
100
4.5
–10
TEMPERATURE (°C)
5
10
3521 G04
3521 G02
1000
5.5
30
140
120
100
80
60
40
20
0
50
70
90 110
3521 G07
3521f