MIC2172 Datasheet, PDF (6/16 Pages) Micrel Semiconductor – 100kHz 1.25A Switching Regulators Preliminary Information

MIC2172/3172
Typical Performance Characteristics
MIC2172 Minimum
Operating Voltage
2.9
2.8
2.7
2.6
Switch Current = 1A
2.5
2.4
2.3
-100 -50 0 50 100 150
Temperature (°C)
Feedback Bias Current
800
700
600
500
400
300
200
100
0
-100 -50 0 50 100 150
Temperature (°C)
Supply Current
15
14
ISW = 0
13
12
D.C. = 90%
11
10
D.C. = 50%
9
8
D.C. = 0%
7
6
5
0
10
20
30
40
V_IN Operating Voltage (V)
Supply Current
(Shutdown Mode)
8
MIC3172
7 V_IN = 40V
6
5
4
3
2
1
0
-100 -50 0 50 100 150
Temperature (°C)
Supply Current
50
40
30
20
δ = 90%
10
δ = 50%
0
0.0 0.5 1.0 1.5 2.0
Switch Current (A)
Switch ON Voltage
1.6
1.4
1.2
TJ = –40°C
1.0 _{TJ = 25°C}
0.8
0.6
0.4
TJ = 125°C
0.2
0.0
0.0
0.5
1.0
1.5
Switch Current (A)
Supply Current
10
9 V_COMP = 0.6V
8
7
6
5
4
3
2
1
0
-100 -50 0 50 100 150
Temperature (°C)
Oscillator Frequency
120
110
100
90
80
70
60
-50
0
50 100 150
Temperature (°C)
4-18
Micrel
Feedback Voltage
Line Regulation
5
4
3
TJ = 125°C
2
1
0
TJ = 25°C
-1
-2
-3
-4
TJ = -40°C
-5
0
10
20
30
40
V_IN Operating (V)
Enable Thresholds
1.4
MIC3172
1.3
ON
1.2
1.1
OFF
1
0.9
0.8
-100 -50 0
50 100 150
Temperature (°C)
Current Limit
4
3
–40°C
2 ^25°C
125°C
1
0
0 20 40 60 80 100
Duty Cycle (%)
Oscillator Frequency
140
MIC2172
130
120
110
100
90
1
10
100
1000
R_ADJ (kΩ)
1997