SC4524A_08 Datasheet, PDF (7/19 Pages) Semtech Corporation – 28V 2A Step-Down Switching Regulator

Curve 2
Curve 3
SC4524A
Typical Characteristics
SC4524A/B
SC4524A
SS270 REV 6-7
Efficie ncy
90
85
V_O=5V
V_O=3.3V
80
V_O=2.5V
75
70
V_O=1.5V
65
Efficiency
90
85
80
V_O=5V
75
V_O=3.3V
70
V_O=2.5V
65
60
60
55
Curve 5^{1MHz, VIN =12V}
50
D₂ =20BQ030
45
55
Curve 6 ⁵⁰
1MHz, V_IN =24V
D₂ =20BQ030
45
40
40
0
0.5
1
1.5
2
0
0.5
1
1.5
Load Current (A)
Load Current (A)
SS270 REV 6-7
SS270 REV 6-7
Feedback Voltage vs Temperature
1.02
V_IN =12V
1.01
1.00
0.99
0.98
0.97
2
-50 -25 0 25 50 75 100 125
Te mperature (^oC)
Frequency Setting Resistor
vs Frequency
1000
V_IN =12V
100
10
Curve 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
Curve 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
25.0
-40^oC
125^oC
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)