Datasheet

LT3640
7
3640f
Typical perForMance characTerisTics
Full Frequency Waveforms Light Load Operation Waveforms
T
A
= 25°C, unless otherwise noted.
Watchdog Upper Boundary
Period vs C
WDT
Watchdog Upper Boundary
Period vs Temperature RST/WDO Pull-Up Current
200ns/DIV
SW1
10V/DIV
I
L1
0.5A/DIV
SW2
5V/DIV
I
L2
0.5A/DIV
3640 G18
V
IN1
= 12V
V
OUT1
= 3.3V/0.5A
V
IN2
= V
OUT1
V
OUT2
= 1.8V/0.5A
500ns/DIV
SW1
10V/DIV
I
L1
0.5A/DIV
SW2
5V/DIV
I
L2
0.5A/DIV
3640 G19
V
IN1
= 12V
V
OUT1
= 3.3V/25mA
V
IN2
= V
OUT1
V
OUT2
= 1.8V/30mA
C
WDT
CAPACITANCE (pF)
0
WATCHDOG UPPER BOUNDARY PERIOD (ms)
120
140
160
100
80
20001000 3000 4000 5000
20
0
60
180
40
3640 G20
TEMPERATURE (°C)
–50
WATCHDOG UPPER BOUNDARY PERIOD (ms)
20
25
30
15
10
50
0
100 150
5
0
35
3640 G21
RST/WDO VOLTAGE (V)
0
RST/WDO PULL-UP CURRENT (µA)
1
0.5
1.5 2
3640 G22
0
10
20
5
15