MIC2172/3172
Micrel, Inc.
Typical Performance Characteristics
MIC2172 Minimum
Operating Voltage
2.9
Minimum Operating Voltage (V)
Feedback Bias Current (nA)
2.8
2.7
2.6
Switch Current = 1A
2.5
2.4
2.3
-100
-50
0
50
100
Temperature (°C)
150
Feedback Bias Current
700
600
500
400
300
200
100
0
-100
-50
0
50
100
Temperature (°C)
150
Feedback Voltage Change (mV)
Feedback Voltage
Line Regulation
5
4
3
2
1
0
-1
-2
-3
-4
-5
0
TJ = -40°C
10
20
30
V
IN
Operating (V)
40
TJ = 125°C
800
TJ = 25°C
Supply Current
15
Supply Current (mA)
14
13
12
11
10
9
8
7
6
5
D.C. = 90%
ISW = 0
Supply Current (µA)
8
7
6
5
4
3
2
1
0
10
20
30
V
IN
Operating Voltage (V)
40
0
-100
Supply Current
(Shutdown Mode)
Enable Pin Voltage (mV)
MIC3172
V
IN
= 40V
1.4
1.3
Enable Thresholds
MIC3172
ON
1.2
1.1
OFF
1
0.9
0.8
-100
-50
0
50
100
Temperature (°C)
150
D.C. = 50%
D.C. = 0%
-50
0
50
100
Temperature (°C)
150
Supply Current
50
Average Supply Current (mA)
40
30
20
10
0
0.0
δ
= 90%
δ
= 50%
Switch ON Voltage (V)
1.6
1.4
Switch ON Voltage
Current Limit
4
TJ = –40°C
TJ = 25°C
Switch Current (A)
1.2
1.0
0.8
0.6
0.4
0.2
3
–40°C
2 25°C
125°C
1
TJ = 125°C
0.5
1.0
1.5
Switch Current (A)
2.0
0.0
0.0
0.5
1.0
Switch Current (A)
1.5
0
0
20
40
60
80
Duty Cycle (%)
100
Supply Current
10
Supply Current (mA)
9
8
7
6
5
4
3
2
1
0
-100
V
COMP
= 0.6V
Frequency (kHz)
120
110
Oscillator Frequency
140
Oscillator Frequency
MIC2172
130
100
f
OSC
(kHz)
0
50
100
Temperature (°C)
150
120
110
100
90
90
80
70
-50
0
50
100
Temperature (°C)
150
60
-50
1
10
100
R
ADJ
(kΩ)
1000
M9999-042205
6
April 2005
MICREL [ MICREL SEMICONDUCTOR ]
