LTC3549 Datasheet, PDF (5/16 Pages) Linear Technology – 250mA Low VIN Buck Regulator in 2mm × 3mm DFN

LTC3549
TYPICAL PERFOR A CE CHARACTERISTICS
(From Typical Application on the front page, except for the resistive divider resistor values)
Oscillator Frequency
vs Temperature
2.35
2.30
V_IN = 1.6V
V_IN = 2.7V
2.25
Oscillator Frequency Shift
vs Input Voltage
2.5
2.0
1.5
1.0
Output Voltage vs Load Current
V_IN = 1.6V, V_OUT = 1.2V
1.205
1.204
1.203
2.20
V_IN = 4.2V
2.15
2.10
2.05
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3549 G07
0.5
0
–0.5
–1.0
–1.5
1.5
2.5
3.5
4.5
INPUT VOLTAGE (V)
5.5
3549 G08
1.202
1.201
BURST
1.200 V_OUT
PULSE SKIP
1.199
0
100
200
LOAD CURRENT (mA)
300
3549 G09
R_DS(ON) vs Input Voltage
0.9
0.8
0.7
0.6
0.5
MAIN SWITCH
0.4
0.3
SYNCHRONOUS SWITCH
0.2
0.1
0
1.5
2.5
3.5
4.5
INPUT VOLTAGE (V)
Dynamic Supply Current vs
Temperature, V_IN = 3.6V,
V_OUT = 1.5V, No Load
350
5.5
3549 G10
R_DS(ON) vs Temperature
0.95
0.85
0.75
0.65
0.55
0.45
0.35
0.25
0.15
–50 –25 0 25 50 75 100 125
TEMPERATURE (°C)
3549 G11
MAIN SWITCH SYNCHRONOUS SWITCH
V_IN = 1.6V
V_IN = 2.7V
V_IN = 4.2V
V_IN = 1.6V
V_IN = 2.7V
V_IN = 4.2V
Switch Leakage vs Temperature
V_IN = 5.5V
250
300
PULSE SKIP
250
200
200
150
SYNCHRONOUS SWITCH
150
100
BURST
50
100
50
MAIN SWITCH
0
–50 –25
0 25 50 75 100 125
TEMPERATURE (°C)
3549 G13
0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3549 G14
Dynamic Input Current
V_OUT = 1.5V, 247kΩ Load
10000
70
Burst Mode
OPERATION
60
50
40
1000
30
20
PULSE SKIP MODE
10
100
0
1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
INPUT VOLTAGE (V)
3549 G12
Switch Leakage vs Input Voltage
1.6
1.4
1.2
1.0
MAIN SWITCH
0.8
0.6
0.4
0.2
0
0
SYNCHRONOUS
SWITCH
2
4
INPUT VOLTAGE (V)
6
3549 G15
3549f
5