LTC3631 Datasheet, PDF (5/22 Pages) Linear Technology – High Effi ciency, High Voltage 100mA Synchronous Step-Down Converter

TYPICAL PERFORMANCE CHARACTERISTICS
LTC3631
Peak Current Trip Threshold
vs R_ISET
240
220 ^{VIN = 10V}
200
180
160
140
120
100
80
60
40
20
0
200 400 600 800 1000 1200
R_ISET (kΩ)
3631 G10
Quiescent Supply Current
vs Temperature
14
V_IN = 10V
12
SLEEP
10
8
6
4
SHUTDOWN
2
0
–40 –10 20 50 80
TEMPERATURE (°C)
110
3631 G13
Switch Leakage Current
vs Temperature
0.6
V_IN = 45V
0.5
0.4
0.3
0.2
0.1
0
–40
SW = 0V
SW = 45V
–10 20 50 80
TEMPERATURE (°C)
110
3631 G16
Peak Current Trip Threshold
vs Input Voltage
250
225
I_SET OPEN
200
175
150
125
R_SET = 500k
100
75
I_SET = GND
50
25
0
0 5 10 15 20 25 30 35 40 45 50
INPUT VOLTAGE (V)
3631 G11
Quiescent Supply Current
vs Input Voltage
14
12
SLEEP
10
8
6
SHUTDOWN
4
2
0
5
15
25
35
V_IN VOLTAGE (V)
Switch On-Resistance
vs Input Voltage
4.5
4.0
3.5
3.0
TOP
2.5
2.0
BOTTOM
1.5
1.0
0.5
0
0
10
20
30
V_IN VOLTAGE (V)
40
50
3631 G14
Switch On-Resistance
vs Temperature
5 _{VIN = 10V}
4
TOP
3
BOTTOM
2
1
0
–40 –10 20 50 80
TEMPERATURE (°C)
RUN Comparator Threshold
Voltages vs Temperature
1.300
1.250
RISING
Operating Waveforms
SWITCH
VOLTAGE
20V/DIV
1.200
1.150
1.100
1.050
FALLING
OUTPUT
VOLTAGE
50mV/DIV
INDUCTOR
CURRENT
100mA/DIV
45
3631 G12
110
3631 G15
1.000
–40
–10 20 50 80
TEMPERATURE (°C)
110
3631 G17
V_IN = 36V
V_OUT = 5V
I_LOAD = 35mA
20μs/DIV
3631 G18
3631fb
5