LTC3642 Datasheet, PDF (4/20 Pages) Linear Technology – High Effi ciency, High Voltage 50mA Synchronous Step-Down Converter

LTC3642
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency vs Load Current
100
FIGURE 10 CIRCUIT
95 ^ISET ^OPEN
V_OUT = 5V
90 _{VIN = 15V}
V_IN = 10V
85
80
V_IN = 45V
75
V_IN = 24V
V_IN = 36V
70
65
60
0.1
1
10
LOAD CURRENT (mA)
100
3642 G01
Feedback Comparator Voltage vs
Temperature
0.801
V_IN = 10V
0.800
0.799
0.798
–40
–10 20 50 80
TEMPERATURE (°C)
110
3642 G04
Peak Current Trip Threshold
vs R_ISET
120
110 ^{VIN = 10V}
100
90
80
70
60
50
40
30
20
10
0 200 400 600 800 1000 1200
R_SET (kΩ)
3642 G07
Line Regulation
0.30
I_LOAD = 25mA
FIGURE 10 CIRCUIT
0.20
0.10
0
–0.10
–0.20
–0.30
5
10 15 20 25 30 35 40 45
V_IN VOLTAGE (V)
3642 G02
Feedback Comparator Hysteresis
vs Temperature
5.6
V_IN = 10V
5.4
5.2
5.0
4.8
4.6
4.4
–40
–10 20 50 80
TEMPERATURE (°C)
110
3642 G05
Quiescent Supply Current vs
Input Voltage
14
12
SLEEP
10
8
6
4
SHUTDOWN
2
0
5
15
25
35
45
V_IN VOLTAGE (V)
3642 G08
Load Regulation
5.05
V_IN = 10V
5.04 _{FIGURE 10 CIRCUIT}
5.03 ^{ISET OPEN}
5.02
5.01
5.00
4.99
4.98
4.97
4.96
4.95
0
10
20
30
40
50
LOAD CURRENT (mA)
3642 G03
Peak Current Trip Theshold vs
Temperature
130
120 ^{VIN = 10V}
110
I_SET OPEN
100
90
80
70
60
R_ISET = 500k
50
40
30
I_SET = GND
20
10
0
–40 –10 20 50 80 110
TEMPERATURE (°C)
3642 G06
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
3642 G09
3642f
4