Datasheet

LT3690
6
3690fa
Typical perForMance characTerisTics
Catch Diode Voltage Drop
(V
GND
– V
SW
) vs I
SW
Minimum Input Voltage
vs Load Current
Minimum Input Voltage
vs Load Current
Switch Voltage Drop vs I
SW
BST Pin Current vs I
SW
Boost Diode Drop (V
BIAS
– V
BST
)
vs I
BST
T
A
= 25°C, unless otherwise noted.
SWITCH CURRENT (A)
0
HS SWITCH VOLTAGE DROP (V)
0.6
0.2
0
0.3
0.4
0.5
0.1
2 4 531
3690 G10
6
SWITCH CURRENT (A)
0
BST PIN CURRENT (mA)
120
40
0
60
80
100
20
2 4 531
3690 G11
6
BST DIODE CURRENT (A)
0
BST DIODE VOLTAGE DROP (V)
1.4
0.4
0
0.6
0.8
1.0
1.2
0.2
1 21.50.5
3690 G12
2.5
VOLTAGE DROP (V)
0
SWITCH CURRENT (A)
8
2
0
3
4
5
6
7
1
0.4 1.41.21.00.6 0.80.2
3690 G13
1.6
LOAD CURRENT (mA)
1
INPUT VOLTAGE (V)
6.5
5.0
4.0
5.5
6.0
4.5
100010010
3690 G14
10000
V
OUT
= 5V
L = 4.7µH
ƒ = 600kHz
LOAD CURRENT (mA)
1
INPUT VOLTAGE (V)
5.0
3.5
2.5
4.0
4.5
3.0
100010010
3690 G15
10000
V
OUT
= 3.3V
L = 4.7µH
ƒ = 600kHz
Maximum V
IN
for Fixed Frequency
SWITCH CURRENT (A)
0
INPUT VOLTAGE (V)
40
5
0
25
30
35
20
10
15
321
3690 G16
4
LIMITED BY
T
J
= 125°C
V
SYNC
> 0.8V, T
A
= 25°C
V
SYNC
> 0.8V, T
A
= 85°C
V
SYNC
< 0.4V, T
A
= 25°C
V
SYNC
< 0.4V, T
A
= 85°C
V
OUT
= 3.3V
L = 3.3µH
ƒ = 600kHz
Switch Current Limit
vs Duty Cycle
Switch Current Limit
vs Temperature
DUTY CYCLE (%)
0
HS SWITCH CURRENT LIMIT (A)
8
6
5
7
4
20 60 8040
3690 G08
100
V
FB
> 0.75V
V
FB
= 0V
TEMPERATURE (°C)
–50
HS SWITCH CURRENT LIMIT (A)
8.0
4.0
6.0
5.0
3.0
4.5
6.5
7.0
7.5
5.5
3.5
50 1000 7525–25
3690 G09
150125
DUTY CYCLE = 10%
DUTY CYCLE = 90%