MIC4684_10 Datasheet, PDF (5/16 Pages) Micrel Semiconductor – 2A High-Efficiency SuperSwitcher Buck Regulator

MIC4684
Typical Characteristics
(T_A = 25°C unless otherwise noted)
5V_OUT Efficiency without Feed
100
Forward Diode
95
90
V_IN
=
8V
85
80
V_IN = 12V
75
70
65
V_IN = 24V
60
55
500
0.2 0.4 0.6 0.8
V_OUT = 5V
1 1.2 1.4 1.6
OUTPUT CURRENT (A)
Efficiency vs. Output Current
with Feed Forward Diode
100
90
80
70
60
50
5V_OUT
3.3V_OUT
2.5V_OUT
1.8V_OUT
40
30
20
10
V_IN = 12V
00 _{0.5 1 1.5 2 2.5 3}
OUTPUT CURRENT (A)
Minimum Duty Cycle
vs. Input Voltage
10.9
V_IN = 12V
10.8 V_OUT = 5V
10.7 ^{VFB = 1.3V}
10.6
10.5
10.4
10.3_{0 5 10 15 20 25 30 35 40}
INPUT VOLTAGE (V)
200
180
160
140
120
100
80
60
40
20
00
Shutdown Current
vs. Input Voltage
V_EN = 0V
5 10 15 20 25 30 35 40
INPUT VOLTAGE (V)
January 2010
3.3V_OUT Efficiency without
100 ^{Feed Forward Diode}
95
90 _{VIN = 8V}
85
80
75
70
V_IN = 12V
65
V_IN = 24V
60
55
500
V_OUT = 3.3V
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
OUTPUT CURRENT (A)
Bootstrap Voltage
vs. Input Voltage
7
6
5
4
3
2
1
V_IN = 12V
V_FB = 1.5V
00 _{5 10 15 20 25 30}
INPUT VOLTAGE (V)
1.255
Reference Voltage
vs. Input Voltage
1.250
1.245
1.240
1.235
1.230
1.225₀
V_IN = 12V
V_OUT = V_REF
I_OUT = 500mA
5 10 15 20 25 30 35 40
INPUT VOLTAGE (V)
Saturation Voltage
vs. Input Voltage
605
600
595
590
585
580
575
570₀
I_OUT = 1A
V_OUT = 5V
5 10 15 20 25 30 35 40
INPUT VOLTAGE (V)
5
Micrel, Inc.
5V_IN Efficiency with Feed
Forward Diode
100
95
90 ^{VOUT = 3.3V}
85
80
V_OUT = 2.5V
75
70
65
60
V_OUT = 1.8V
55
500
0.5
V_IN = 5.0V
1
1.5
2
OUTPUT CURRENT (A)
Bootstrap Drive Current
vs. Input Voltage
350
300
250
200
150
100
50
V_IN = 12V
V_FB = 1.5V
00 _{2 4 6 8 10 12 14 16 18 20}
INPUT VOLTAGE (V)
Quiescent Current
vs. Input Voltage
6.3
6.2
6.1
6
5.9
5.8
V_EN= 5V
5.7_{0 5 10 15 20 25 30 35 40}
INPUT VOLTAGE (V)
Foldback Frequency
vs. Input Voltage
51.5
51
50.5
50
49.5
49
48.5₀
V_FB = 0V
5 10 15 20 25 30 35 40
INPUT VOLTAGE (V)
M9999-012610