mic4684 Micrel Semiconductor, mic4684 Datasheet - Page 5

• Manufacturer Part Number: mic4684
• Description: Mic4684 2a High-efficiency Buck Regulator
• Manufacturer: Micrel Semiconductor

Typical Characteristics
(T
February 2005
MIC4684
A
= 25°C unless otherwise noted)
100
200
180
160
140
120
100
100
10.9
10.8
10.7
10.6
10.5
10.4
10.3
95
90
85
80
75
70
65
60
55
50
90
80
70
60
50
40
30
20
10
80
60
40
20
5V
0
0
Efficiency vs. Output Current
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
0
0
0
V
OUT
with Feed Forward Diode
IN
V
V
V
IN
OUT
FB
5
0.5
= 8V
5
Minimum Duty Cycle
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
Shutdown Current
Efficiency without Feed
V
= 12V
vs. Input Voltage
INPUT VOLTAGE (V)
= 1.3V
vs. Input Voltage
INPUT VOLTAGE (V)
IN
10 15 20 25 30 35 40
Forward Diode
10 15 20 25 30 35 40
= 5V
= 24V
1
1.5
V
IN
= 12V
V
IN
V
2
V
OUT
= 12V
EN
5V
3.3V
2.5V
1.8V
2.5
= 0V
= 5V
OUT
OUT
OUT
OUT
3
7
6
5
4
3
2
1
0
1.255
1.250
1.245
1.240
1.235
1.230
1.225
100
605
600
595
590
585
580
575
570
0
95
90
85
80
75
70
65
60
55
50
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
0
3.3V
0
V
5
Bootstrap Voltage
IN
vs. Input Voltage
INPUT VOLTAGE (V)
5
Feed Forward Diode
= 8V
OUTPUT CURRENT (A)
Saturation Voltage
OUT
5
vs. Input Voltage
INPUT VOLTAGE (V)
V
Reference Voltage
10 15 20 25 30 35 40
10
IN
vs. Input Voltage
INPUT VOLTAGE (V)
10 15 20 25 30 35 40
Efficiency without
= 24V
15
5
V
IN
V
V
20
= 12V
IN
FB
V
V
V
I
I
V
OUT
OUT
OUT
IN
OUT
OUT
= 12V
= 1.5V
= 12V
25
= 500mA
= 1A
= 3.3V
= V
= 5V
REF
30
6.3
6.2
6.1
5.9
5.8
5.7
100
350
300
250
200
150
100
51.5
50.5
49.5
48.5
95
90
85
80
75
70
65
60
55
50
50
6
51
50
49
0
0
0
0
0
V
Bootstrap Drive Current
OUT
2 4 6 8
5V
5
Quiescent Current
5
OUTPUT CURRENT (A)
Foldback Frequency
vs. Input Voltage
INPUT VOLTAGE (V)
V
IN
vs. Input Voltage
INPUT VOLTAGE (V)
10 15 20 25 30 35 40
= 3.3V
OUT
0.5
vs. Input Voltage
INPUT VOLTAGE (V)
10 15 20 25 30 35 40
Efficiency with Feed
Forward Diode
= 1.8V
10 12 14 16 18 20
1
V
V
V
IN
FB
OUT
V
V
V
IN
1.5
= 12V
EN
= 1.5V
FB
= 5.0V
= 2.5V
= 5V
= 0V
M9999-021705
Micrel, Inc.
2