LT3685 LINER [Linear Technology], LT3685 Datasheet - Page 6

• Manufacturer Part Number: LT3685
• Description: 36V, 4A, 1.5MHz Synchronous Step-Down Switching Regulator
• Manufacturer: LINER [Linear Technology]

LT3690
TYPICAL PERFORMANCE CHARACTERISTICS
6
120
100
6.5
6.0
5.5
5.0
4.5
4.0
80
60
40
20
8
7
6
5
4
0
0
0
1
Minimum Input Voltage
vs Load Current
BST Pin Current vs I
Switch Current Limit
vs Duty Cycle
V
L = 4.7µH
ƒ = 600kHz
OUT
= 5V
1
20
10
SWITCH CURRENT (A)
LOAD CURRENT (mA)
DUTY CYCLE (%)
V
2
V
FB
FB
40
> 0.75V
= 0V
100
3
60
SW
4
1000
80
5
3690 G08
3690 G11
3690 G14
10000
100
6
8.0
7.5
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
1.4
1.2
1.0
0.8
0.6
0.4
0.2
5.0
4.5
4.0
3.5
3.0
2.5
0
–50
1
0
Minimum Input Voltage
vs Load Current
Boost Diode Drop (V
vs I
Switch Current Limit
vs Temperature
V
L = 4.7µH
ƒ = 600kHz
OUT
–25
BST
= 3.3V
0.5
10
BST DIODE CURRENT (A)
LOAD CURRENT (mA)
0
TEMPERATURE (°C)
1
25
100
DUTY CYCLE = 10%
DUTY CYCLE = 90%
50
1.5
BIAS
75
1000
– V
2
100
BST
T
3690 G09
3690 G12
3690 G15
A
)
10000
= 25°C, unless otherwise noted.
125
2.5
0.6
0.5
0.4
0.3
0.2
0.1
40
35
30
25
20
15
10
8
7
6
5
4
3
2
1
0
0
5
0
0
0
0
Catch Diode Voltage Drop
(V
Maximum V
Switch Voltage Drop vs I
GND
0.2
1
– V
0.4
1
SWITCH CURRENT (A)
SWITCH CURRENT (A)
SW
VOLTAGE DROP (V)
2
0.6
IN
) vs I
for Fixed Frequency
0.8
V
V
V
V
3
2
SW
LIMITED BY
SYNC
SYNC
SYNC
SYNC
T
J
= 125°C
1.0
> 0.8V, T
> 0.8V, T
< 0.4V, T
< 0.4V, T
4
1.2
SW
V
L = 3.3µH
ƒ = 600kHz
3
OUT
A
A
A
A
5
= 25°C
= 85°C
= 25°C
= 85°C
1.4
= 3.3V
3690 G13
3690 G10
3690 G16
3690f
1.6
6
4