lt3688fe Linear Technology Corporation, lt3688fe Datasheet - Page 6

• Manufacturer Part Number: lt3688fe
• Description: Lt3688 - Dual 800ma Step-down Switching Regulator With Power-on Reset And Watchdog Timer
• Manufacturer: Linear Technology Corporation

LT3688
TYPICAL PERFORMANCE CHARACTERISTICS
10mV/DIV
6
0.2A/DIV
5V/DIV
V
V
2.5
2.0
1.5
1.0
0.5
OUT
25
20
15
10
SW
0
5
0
I
L
0
0
EN/UVLO Pin Current
Switching Frequency vs R
V
I
Switching Waveforms,
Burst Mode Operation
LOAD
IN
5
= 12V; FRONT PAGE APPLICATION
= 7mA
50
10
PIN VOLTAGE (V)
15
R
T
100
5μs/DIV
20
(kΩ)
25
150
30
T
35
3688 G13
3688 G17
3688 G20
200
40
10mV/DIV
0.2A/DIV
5V/DIV
V
V
OUT
1.50
1.40
1.30
1.20
1.10
1.00
SW
1.2
1.0
0.8
0.6
0.4
0.2
0.0
I
L
–50 –25
–50 –25
EN/UVLO Pin Threshold
Switching Frequency
vs Temperature
Switching Waveforms,
Transition from Burst Mode
to Full Frequency
V
I
LOAD
IN
R
THRESHOLD FALLING
T
= 12V; FRONT PAGE APPLICATION
= 49.9k
= 40mA
0
0
TEMPERATURE (°C)
TEMPERATURE (°C)
25
25
5μs/DIV
50
50
75
75
100 125
100 125
T
3688 G14
3688 G18
3688 G21
A
= 25°C unless otherwise noted.
150
150
10mV/DIV
0.2A/DIV
5V/DIV
V
V
OUT
SW
200
150
100
900
800
700
600
500
400
300
200
100
I
50
L
0
0
–50 –20
0
Boost Diode Forward Voltage
V
I
Minimum Switch On-Time
Switching Waveforms, Full
Frequency Continuous Operation
LOAD
I
IN
SW
= 12V; FRONT PAGE APPLICATION
= 700mA
= 160mA
10
0
TEMPERATURE (°C)
CURRENT (mA)
25
20
5μs/DIV
50
30
75
100 125
40
3688 G16
3688 G19
3688 G22
3688f
150
50