LT3976 Datasheet, PDF (5/28 Pages) Linear Technology – 40V, 5A, 2MHz Step-Down Switching Regulator with 3.3μA Quiescent Current

LT3976
Typical Performance Characteristics T_A = 25°C, unless otherwise noted.
Reference Voltage
1.230
1.225
1.220
1.215
1.210
1.205
1.200
1.195
1.190
1.185
1.180
1.175
1.170
–55 –25
5 35 65 95
TEMPERATURE (°C)
125 155
3976 G07
Load Regulation
0.5
V_IN = 12V
0.4 V_OUT = 3.3V
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
0
1
2
3
4
5
LOAD CURRENT (A)
3976 G08
Line Regulation
0.05
0.04
V_OUT = 5V
LOAD = 1A
0.03
0.02
0.01
0
–0.01
–0.02
–0.03
–0.04
–0.05
5
10 15 20 25 30
INPUT VOLTAGE (V)
35 40
3976 G09
Thermal Derating
6
5
12V
24V
4
36V
H-GRADE
3
I-GRADE
2
1 V_OUT = 3.3V
f_SW = 400kHz
2.5in × 2.5in 4-LAYER BOARD
0
0 25 50 75 100
TEMPERATURE (°C)
LIMITED BY MAXIMUM
JUNCTION TEMPERATURE
Θ_JA = 40°C/W
125 150
3976 G10
Switch Current Limit
12
30% DUTY CYCLE
10
30% DUTY CYCLE
9 VSS = 3V
8
7
6
5
4
3
2
1
0
0 0.2 0.4 0.6 0.8
FB PIN VOLTAGE (V)
1.0 1.2
3976 G14
11
10
9
8
7
6
–55 –25
5 35 65 95
TEMPERATURE (°C)
125 155
3976 G13
Thermal Derating
6
5
12V
4
24V
36V
H-GRADE
3
I-GRADE
2
1 V_OUT = 5V
f_SW = 400kHz
2.5in × 2.5in 4-LAYER BOARD
0
0 25 50 75 100
TEMPERATURE (°C)
LIMITED BY MAXIMUM
JUNCTION TEMPERATURE
Θ_JA = 40°C/W
Current Limit Foldback
10
30% DUTY CYCLE
9 V_SS = 3V
8
7
6
5
4
3
2
1
0
0 0.2 0.4 0.6 0.8
FB PIN VOLTAGE (V)
125 150
3976 G11
1.0 1.2
3976 G14
For more information www.linear.com/3976
Switch Current Limit
10.0
9.5
9.0
8.5
8.0
7.5
7.0
0
0.2
0.4
0.6
0.8
1.0
DUTY CYCLE
3976 G12
Soft-Start
10
30% DUTY CYCLE
9
8
V_FB = 1V
V_FB = 0V
7
6
5
4
3
2
1
0
0
0.5
1.0
1.5
2.0
2.5
SS PIN VOLTAGE (V)
3976 G15
3976f
5