MIC4685
Micrel
Typical Characteristics
(T
A
= 25°C unless otherwise noted)
Efficiency
vs. Output Current
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
Standard
Configuration
V
OUT
= 5.0V
V
IN
= 8V
V
IN
= 30V
100
V
IN
= 12V
EFFICIENCY (%)
90
80
70
60
50
40
30
20
Efficiency
vs. Output Current
V
IN
= 8V
EFFICIENCY (%)
100
Efficiency
vs. Output Current
90 V
IN
= 8V
80
V
IN
= 24V
V
IN
= 30V
V
IN
= 12V
70
60
50
40
30
20
V
IN
= 30V
V
IN
= 12V
10
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
10
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
Standard
Configuration
V
OUT
= 3.3V
10
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
Standard
Configuration
V
OUT
= 2.5V
Efficiency
vs. Output Current
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
Standard
Configuration
V
OUT
= 1.8V
V
IN
= 30V
V
IN
= 12V
V
IN
= 8V
EFFICIENCY (%)
V
IN
= 24V
100
90
80
70
60
50
40
30
20
Efficiency
vs. Output Current
V
IN
= 7.5V
EFFICIENCY (%)
100
90
80
V
IN
= 12V
70
60
50
40
30
20
Efficiency
vs. Output Current
V
IN
= 4.5V
V
IN
= 12V
V
IN
= 5V
V
IN
= 16V
V
IN
= 16V
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
10
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
Bootstrap
Configuration
V
OUT
= 5.0V
10
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
Bootstrap
Configuration
V
OUT
= 3.3V
Efficiency
vs. Output Current
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
Bootstrap
Configuration
V
OUT
= 2.5V
V
IN
= 5V
V
IN
= 12V
EFFICIENCY (%)
90
80
70
60
50
40
30
20
10
Efficiency
vs. Output Current
V
IN
= 5V
6.3
INPUT CURRENT (mA)
V
IN
= 12V
6.2
6.1
6
5.9
5.8
Quiescent Current
vs. Input Voltage
V
IN
= 16V
V
IN
= 16V
10
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
OUTPUT CURRENT (A)
Bootstrap
Configuration
V
OUT
= 1.8V
V
EN
= 5V
5.7
0
5
10 15 20 25 30 35 40
INPUT VOLTAGE (V)
Bootstrap Voltage
vs. Input Voltage
7
BOOTSTRAP CURRENT (mA)
BOOTSTRAP VOLTAGE (V)
6
5
4
3
2
1
0
0
5
V
IN
= 12V
V
FB
= 1.5V
10 15 20 25
INPUT VOLTAGE (V)
30
350
300
250
200
150
100
50
Bootstrap Drive Current
vs. Input Voltage
12
10
DUTY CYCLE (%)
8
6
4
2
0
0
Minimum Duty Cycle
vs. Input Voltage
0
0 2 4 6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
V
IN
= 12V
V
FB
= 1.5V
V
OUT
= 1.8V
5
10 15 20 25
INPUT VOLTAGE (V)
30
September 2002
5
MIC4685
MICREL [ MICREL SEMICONDUCTOR ]
