LTC3425_15 Datasheet, PDF (6/24 Pages) Linear Technology – 5A, 8MHz, 4-Phase Synchronous Step-Up DC/DC Converter

LTC3425
TYPICAL PERFOR A CE CHARACTERISTICS
Maximum Output Current
in Burst Mode Operation
350
T_A = 25°C
300
V_OUT = 3.3V
250
200
V_OUT = 5V
150
100
50
0
1 1.5 2 2.5 3 3.5 4 4.5 5
V_IN (V)
3425 G20
Automatic Burst Mode Thresholds
vs V_IN
100
V_OUT = 5V
90
V_OUT = 3.3V
80
LEAVE Burst Mode OPERATION
70
60
ENTER Burst Mode OPERATION
V_OUT = 3.3V
50
40
1.5
V_OUT = 5V
T_A = 25°C
R_BURST = 33k
2
2.5
3
3.5
4
V_IN (V)
3425 G23
Minimum Start-Up Voltage
vs Temperature
1.00
0.95
0.90
0.85
0.80
0.75
0.70
–45 –25 –5 15 35 55 75 95 115
TEMPERATURE (°C)
3425 G26
6
Maximum Start-Up Load vs V_IN
(Constant Current Load)
0.7
T_A = 25°C
0.6
0.5
V_OUT = 3.3V
0.4
V_OUT = 5V
0.3
0.2
0.1
0
0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6
V_IN (V)
3425 G21
Soft-Start Charging Current
vs Temperature
3.0
V_IN > 2.3V
2.5
2.0
V_IN < 2.3V
1.5
(START-UP MODE)
1.0
0.5
0
–45 –25 –5 15 35 55 75 95 115
TEMPERATURE (°C)
3425 G24
PGOOD Threshold vs Temperature
11.8
11.7
11.6
11.5
11.4
11.3
11.2
11.1
11.0
10.9
10.8
–45 –25 –5 15 35 55 75 95 115
TEMPERATURE (°C)
3425 G27
Automatic Burst Mode Current
Thresholds vs R_BURST
100
T_A = 25°C
LEAVE
Burst Mode
OPERATION
ENTER
Burst Mode
10
OPERATION
1
10
100
1000
BURST RESISTOR (kΩ)
3425 G22
Shutdown Voltage vs Temperature
0.450
0.425
0.400
0.375
0.350
0.325
0.300
–45 –25 –5 15 35 55 75 95 115
TEMPERATURE (°C)
3425 G25
PMOS Reverse Current in Forced
CCM vs Temperature
800
750
700
650
600
550
500
450
400
350
300
–45 –25 –5 15 35 55 75 95 115
TEMPERATURE (°C)
3425 G28
3425f