LTC3125_15 Datasheet, PDF (5/18 Pages) Linear Technology – 1.2A Synchronous Step-Up DC/DC Converter with Input Current Limit

LTC3125
TYPICAL PERFORMANCE CHARACTERISTICS (T_A = 25°C unless otherwise noted)
R_DS(ON) vs V_OUT
0.450
0.400
0.350
0.300
0.250
PMOS
0.200
0.150
NMOS
0.100
0.050
1.5 2
2.5 3 3.5 4 4.5 5
V_OUT (V)
3125 G12
Feedback vs Temperature
0.50
NORMALIZED TO 25°C
0.25
0
–0.25
–0.50
–0.75
–1.00
–50 –30
–10 10 30 50
TEMPERATURE (°C)
70 90
3125 G15
R_DS(ON) vs Temperature
240
V_OUT = 4V
220
PMOS
200
180
160
140
NMOS
120
100
–50 –30
–10 10 30 50
TEMPERATURE (°C)
70 90
3125 G13
Current Sense Voltage (V_RPROG)
vs Temperature
0.50
NORMALIZED TO 25°C
0.25
0
–0.25
–0.50
–0.75
–1.00
–50 –30
–10 10 30 50
TEMPERATURE (°C)
70 90
3125 G15
Oscillator Frequency
vs Temperature
10
NORMALIZED TO 25°C
8
6
4
2
0
–2
–4
–6
–8
–10
–50 –25 0
25 50
TEMPERATURE (°C)
75 100
3125 G14
Burst Mode Current vs V_OUT
16.0
15.5
15.0
14.5
14.0
13.5
13.0
1.5 2
2.5 3 3.5 4
V_OUT (V)
4.5 5
3125 G17
V_OUT and I_IN During Soft-Start
V_OUT
2V/DIV
SHDN
5V/DIV
INPUT
CURRENT
200mA/DIV
V_IN = 3.3V
V_OUT = 4.5V
C_OUT = 4.4mF
L = 2.7μH
BURST
CURRENT
20ms/DIV
3125 G18
V_OUT and I_IN During Soft-Start
V_OUT
2V/DIV
SHDN
5V/DIV
INPUT
CURRENT
200mA/DIV
V_IN = 3.3V
V_OUT = 4.5V
C_OUT = 0.47F
L = 2.7μH
1s/DIV
3125 G19
3125fa
5