SC4524B_08 Datasheet, PDF (7/18 Pages) Semtech Corporation – 18V 2A Step-Down Switching Regulator

(2)
(3)
SC4524B
Typical Characteristics
SC4524A/B
SC4524A/B
SS270 REV 6-7
90
85
80
75
70
65
60
55
5₍0₅₎
45
40
0
SS270 REV 6-7
Efficiency
90
V _O=5V
V _O=3.3V
85
V _O=2.5V
80
75
70
V _O=1.5V
65
60
1MHz, V_IN =12V
D₂ =20BQ030
55
50₍₆₎
45
40
0.5
1
1.5
2
0
Load Current (A)
SS270 REV 6-7
Efficie ncy
V _O=3.3V
V _O=2.5V
V _O=1.5V
V_O=1.0V
1MHz, V_IN=5V
D₂ =20BQ030
0.5
1
1.5
2
Load Current (A)
Feedback Voltage vs Temperature
1.02
V_IN =12V
1.01
1.00
0.99
0.98
0.97
-50 -25 0 25 50 75 100 125
Tempe rature (^oC)
1000
Frequency Setting Resistor
vs Frequency
V_IN =12V
100
10
(8)
1
0
0.5
1
1.5
2
2.5
Frequency (MHz)
Frequency vs Temperature
1.2
R_OSC=93.1k
1.1
1.0
R_OSC=12.1k
0.9
(9)
0.8
-50 -25
0 25 50 75 100 125
Temperature (^oC)
Foldback Frequency vs V_FB
1.25
1
0.75
R_OSC=93.1k
0.5
0.25
T_A =25^oC
R_OSC=12.1k
0
0.0 0.2 0.4 0.6 0.8 1.0
VFB (V)
SS270 REV 6-7
SS270 REV 6-7
SS270 REV 6-7
Switch Saturation Voltage
vs Switch Current
300
250
Switch Current Limit vs Temperature
4.5
4.0
BST Pin Current vs Switch Current
100.0
75.0
V_IN =12V
V_BST =15V
200
-40^oC
3.5
150
125^oC
25^oC
3.0
100
50.0
-40^oC
125^oC
25.0
50
0.0 0.5 1.0 1.5 2.0 2.5
Switch Current (A)
2.5
-50 -25
0 25 50 75 100 125
Temperature (^oC)
0.0
0 0.5 1 1.5 2 2.5 3
Switch Current (A)