LT3505 Datasheet, PDF (4/24 Pages) Linear Technology – 1.2A, Step-Down Switching Regulator in 3mm × 3mm DFN

LT3505
TYPICAL PERFORMANCE CHARACTERISTICS
Efficiency (V_OUT = 5V, L = 10µH,
f_SW = 750kHz)
95 _{TA = 25°C}
90
85
80
75
70
65
60
55
50
0
V_IN = 8V
V_IN = 12V
V_IN = 24V
0.2 0.4 0.6 0.8 1.0 1.2
LOAD CURRENT (A)
Efficiency (V_OUT = 5V, L = 4.7µH,
f_SW = 2.2MHz)
95
T_A = 25°C
90
85
80
75
70
65
60
55
50
0
V_IN = 8V
V_IN = 12V
0.2 0.4 0.6 0.8 1.0 1.2
LOAD CURRENT (A)
Max Load Current (V_OUT = 3.3V,
L = 2.2µH, f_SW = 2.2MHz)
1.8
1.7 ^{TA = 25°C}
1.6
TYPICAL
1.5
1.4
1.3
MINIMUM
1.2
1.1
1.0
*10% DROPOUT
0.9
0.8
5 6 7 8 9 10 11 12
INPUT VOLTAGE (V)
3505 G07
Efficiency (V_OUT = 3.3V, L = 10µH,
f_SW = 750kHz)
95 _{TA = 25°C}
90
85
80
75
70
65
60
55
50
0
V_IN = 8V
V_IN = 12V
V_IN = 24V
0.2 0.4 0.6 0.8 1.0 1.2
LOAD CURRENT (A)
Max Load Current (V_OUT = 3.3V,
L = 6.8µH, f_SW = 750kHz)
1.7
T_A = 25°C
1.6
TYPICAL
1.5
1.4
MINIMUM
1.3
1.2
1.1
*10% DROPOUT
1.0
0.9
0.8
5 7 9 11 13 15 17 19
INPUT VOLTAGE (V)
3505 G05
Max Load Current (V_OUT = 5V,
L = 3.3µH, f_SW = 2.2MHz)
1.80
1.70 ^{TA = 25°C}
1.60
1.50
TYPICAL
1.40
1.30
MINIMUM
1.20
1.10
1.00
*10% DROPOUT
0.90
0.80
7 8 9 10 11 12 14 16 18
INPUT VOLTAGE (V)
3505 G08
4
Efficiency (V_OUT = 3.3V,
L = 4.7µH, f_SW = 2.2MHz)
95
T_A = 25°C
90
85
80
75
70
65
60
55
50
0
V_IN = 8V
V_IN = 12V
0.2 0.4 0.6 0.8 1.0 1.2
LOAD CURRENT (A)
Max Load Current (V_OUT = 5V,
f_SW = 750kHz)
1.7
1.6 ^{TA = 25°C TYPICAL, L = 22µH}
1.5
TYPICAL, L = 10µH
1.4
1.3
MINIMUM, L = 10µH
1.2
1.1
*10% DROPOUT
1.0
0.9
0.8
6 8 10 12 14 16 18 20 22 24 26 28 30
INPUT VOLTAGE (V)
3505 G06
Switch Voltage Drop
500
450
400
T_A = 85°C
350
300
T_A = 25°C
250
200
T_A = –45°C
150
100
50
0
0
300 600 900 1200 1500
SWITCH CURRENT (mA)
3505 G09
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