Datasheet

LT3689/LT3689-5
6
3689fe
For more information www.linear.com/LT3689
TYPICAL PERFORMANCE CHARACTERISTICS
Switching Frequency vs R
T
Switching Frequency
Frequency Foldback
Minimum Switch On-Time
Overvoltage Lockout V
IN
Fixed Undervoltage Lockout
BST Pin Current Feedback Voltage
SWITCH CURRENT (mA)
0
BST PIN CURRENT (mA)
15
20
10
5
400 800
200
600 1000
0
25
3689 G13
T
A
= 125°C
T
A
= –50°C
T
A
= 25°C
TEMPERATURE (°C)
0.790
FEEDBACK VOLTAGE (V)
0.795
0.800
0.805
0.810
3689 G14
–50 –25
0
25 50 10075 125 150
FREQUENCY (MHz)
0
0
R
T
(k)
10
20
30
40
50
0.4
0.8 1.2 1.6
3689 G16
2 2.4
T
A
= 25°C
TEMPERATURE (°C)
500
600
700
800
550
650
750
850
3689 G17
–50 25 75
–25 0
50 100 150125
R
T
= 20.5k
FB VOLTAGE (mV)
0
SWITCHING FREQUENCY (kHz)
800
1000
600
400
200 300 500
100
400 600
800
700 900
200
0
1200
3689 G18
T
A
= 25°C
R
T
= 12.7k
TEMPERATURE (°C)
0
20
60
100
40
80
120
3689 G19
–50 25 75
–25 0
50 100 150125
I
LOAD
= 700mA
TEMPERATURE (°C)
36
OVERVOLTAGE LOCKOUT (V)
37
38
39
40
3689 G20
–50 –25
0
25 50 10075 125 150
TEMPERATURE (°C)
3.1
V
IN
UVLO (V)
3.2
3.3
3.4
3.5
3689 G21
V
IN
FALLING
V
IN
RISING
–50 –25
0
25 50 10075 125 150
Output Voltage
TEMPERATURE (°C)
OUTPUT VOLTAGE (V)
3689 G15
–50 –25
0
25 50 10075 125 150
4.95
4.97
4.99
5.01
5.03
5.05
4.96
4.98
5.00
5.02
5.04