Datasheet

LTC3869/LTC3869-2
6
38692fa
For more information www.linear.com/LTC3869
Typical perForMance characTerisTics
Current Sense Threshold
vs I
TH
Voltage
Maximum Current Sense
Threshold vs Common Mode
Voltage
Maximum Current Sense
Threshold vs Duty Cycle
Maximum Current Sense Voltage
vs Feedback Voltage (Current
Foldback)
Tracking Up and Down
with External Ramp
Quiescent Current without EXTV
CC
vs Temperature INTV
CC
Line Regulation
V
IN
= 12V
V
OUT1
= 1.8V, 1.5Ω LOAD
V
OUT2
= 1.2V, 1Ω LOAD
10ms/DIV
3869 G10
TK/SS1
TK/SS2
2V/DIV
V
OUT1
V
OUT2
500mA/DIV
V
OUT1
V
OUT2
INTV
CC
VOLTAGE (V)
5.5
5.0
4.5
4.0
3.0
3.5
2.5
2.0
INPUT VOLTAGE (V)
0 10 30
3869 G12
4020
V
ITH
(V)
0
–40
V
SENSE
(mV)
–20
0
20
40
60
80
0.5 1 1.5 2
3869 G13
I
LIM
= GND
I
LIM
= FLOAT
I
LIM
= INTV
CC
V
SENSE
COMMON MODE VOLTAGE (V)
0
CURRENT SENSE THRESHOLD (mV)
30
40
50
12
20
10
0
2 6
8 10
4
60
70
80
3869 G14
I
LIM
= GND
I
LIM
= FLOAT
I
LIM
= INTV
CC
60
80
40
20
50
70
30
10
0
DUTY CYCLE (%)
0
CURRENT SENSE THRESHOLD (mV)
60
100
20 40 80
3869 G15
I
LIM
= GND
I
LIM
= FLOAT
I
LIM
= INTV
CC
FEEDBACK VOLTAGE (V)
0
MAXIMUM CURRENT SENSE THRESHOLD (mV)
30
40
50
0.6
20
10
0
0.1 0.3
0.4 0.5
0.2
60
70
90
80
3869 G16
I
LIM
= GND
I
LIM
= FLOAT
I
LIM
= INTV
CC
T
A
= 25°C, unless otherwise noted.
QUIESCENT CURRENT (mA)
4.0
3.0
2.0
1.0
3.5
2.5
1.5
0.5
0
TEMPERATURE (°C)
–50 500 100
3869 G11
12525–25 75
Coincident Tracking
5ms/DIV
3869 G09
RUN
2V/DIV
V
OUT1
V
OUT2
1V/DIV
V
OUT1
V
OUT2
V
OUT1
= 1.8V, 1.5Ω LOAD
V
OUT2
= 1.2V, 1Ω LOAD