LT1506
TYPICAL PERFORMANCE CHARACTERISTICS
Frequency Foldback
SWITCHING FREQUENCY (kHz) OR CURRENT (µA)
500
550
540
400
FREQUENCY (kHz)
300
510
500
490
480
470
CORE LOSS (W)
SWITCHING
FREQUENCY
200
100
FEEDBACK PIN
CURRENT
0
0
0.5
1.5
2.0
1.0
FEEDBACK PIN VOLTAGE (V)
2.5
1506 G10
Maximum Load Current
at V
OUT
= 5V
4.4
L= 10µH
4.2
4.0
LOAD CURRENT (A)
3.8
3.6
3.4
3.2
3.0
2.8
2.6
5
7
11
9
INPUT VOLTAGE (V)
13
15
1506 G17
LOAD CURRENT (A)
4.0
3.8
3.6
3.4
L= 1.8µH
3.2
3.0
4
6
8
10
12
14
1506 G13
BOOST PIN CURRENT (mA)
L= 5µH
L= 3µH
L= 1.8µH
Current Limit Foldback
7
6
FOLDBACK
CHARACTERISTICS
THRESHOLD VOLTAGE (V)
5
4
3
2
SWITCH VOLTAGE (mV)
OUTPUT CURRENT (A)
POSSIBLE UNDESIRED
CURRENT
STABLE POINT FOR
SOURCE
CURRENT SOURCE
LOAD
LOAD*
RESISTOR
LOAD
MOS LOAD
1
0
0
20
40
60
80
100
1506 G18
OUTPUT VOLTAGE (%)
Kool Mµ is a registered trademark of Magnetics, Inc.
Metglas is a registered trademark of AlliedSignal Inc.
*See “More Than Just Voltage Feedback” in the Applications Information section.
U W
Switching Frequency
1.0
Inductor Core Loss for 3.3V Output
530
520
0.1
TYPE 52
Kool Mµ
®
0.01
PERMALLOY
µ
= 125
Metglas
®
460
450
– 50
–25
0
25
50
75
100
125
0.001
0
2
4
6
INDUCTANCE (µH)
8
10
TEMPERATURE (°C)
1506 G11
1506 G01
Maximum Load Current
at V
OUT
= 3.3V
4.4
L= 10µH
4.2
L= 5µH
100
90
80
70
60
50
40
30
20
10
0
BOOST Pin Current
DUTY CYCLE = 100%
L= 3µH
0
1
INPUT VOLTAGE (V)
3
2
4
SWITCH CURRENT (A)
5
1506 G14
V
C
Pin Shutdown Threshold
1.4
SHUTDOWN
1.2
Switch Voltage Drop
500
450
400
350
300
250
200
150
100
50
25°C
125°C
1.0
– 40°C
0.8
0.6
0.4
–50
0
–25
100
JUNCTION TEMPERATURE (°C)
0
25
50
75
125
0
1
4
3
SWITCH CURRENT (A)
2
5
1506 G16
1506 G15
5
LINER [ LINEAR TECHNOLOGY ]
