LTC3541-1 Datasheet, PDF (5/20 Pages) Linear Technology – High Efficiency Buck + VLDO Regulator

TYPICAL PERFOR A CE CHARACTERISTICS
LTC3541-1
VLDO Dropout Voltage vs
Load Current
100
V_OUT = 1.5V
80
V_IN = 3V
V_IN = 3.6V
60
V_IN = 4.2V
40
Buck (Burst) Plus VLDO Bias
Current vs VLDO Load Current
250
V_IN = 3.6V
I_LOAD(BUCK) = 0
200 ^{IBIAS = IVIN + ILVIN – ILOAD}
150
100
Output (Auto Start-Up Sequence,
Buck in Pulse Skip) vs Time
V_OUT
2V/DIV
LV_OUT
2V/DIV
V_IN
2V/DIV
20
0
0 50 100 150 200 250 300
LOAD CURRENT (mA)
35411 G07
Oscillator Frequency
vs Temperature
2.50
V_IN = 3.6V
2.45
2.40
2.35
2.30
2.25
2.20
2.15
2.10
2.05
2.00
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
35411 G10
Buck Reference vs Temperature
0.820
0.816 ^{VIN = 3.6V}
0.812
0.808
0.804
0.800
0.796
0.792
0.788
0.784
0.780
–50 –25
0 25 50 75 100 125
TEMPERATURE (°C)
53411 G13
50
0
0.1
1
10
100
LOAD CURRENT (mA)
1000
35411 G08
I_VOUT = 400mA 4ms/DIV
I_LVOUT = 30mA
35411 G09
Oscillator Frequency
vs Supply Voltage
2.5
V_IN = 3.6V
2.4
2.3
2.2
2.1
2.0
3
4
5
SUPPLY VOLTAGE (V)
6
35411 G11
VLDO/Linear Regulator Reference
vs Temperature
0.410
0.408 ^{VIN = 3.6V}
0.406
0.404
0.402
0.400
0.398
0.396
0.394
0.392
0.390
–50 –25
0 25 50 75 100 125
TEMPERATURE (°C)
53411 G12
R_DS(ON) vs Temperature
0.700
Buck (Burst) and VLDO Output
0.600
0.500
0.400
SYNCH SWITCH
0.300
LV_OUT
10mV/DIV
AC COUPLED
V_OUT
10mV/DIV
AC COUPLED
0.200
0.100 ^{MAIN SWITCH}
0
–50 –25 0 25 50
V_IN = 2.5V
V_IN = 3.6V
V_IN = 5.5V
75 100 125
TEMPERATURE (°C)
35411 G14
V_IN = 3.6V
2µs/DIV
LV_OUT = 1.5V
V_OUT = 1.8V
I_LOAD = 50mA
Burst Mode OPERATION
35411 G15
35411fa