Datasheet

LTC3728
5
3728fg
TYPICAL PERFORMANCE CHARACTERISTICS
Effi ciency vs Output Current and
Mode (Figure 13)
Effi ciency vs Output Current
(Figure 13)
Effi ciency vs Input Voltage
(Figure 13)
Supply Current vs Input Voltage
and Mode (Figure 13) EXTV
CC
Voltage Drop
INTV
CC
and EXTV
CC
Switch
Voltage vs Temperature
Internal 5V LDO Line Regulation
Maximum Current Sense
Threshold vs Duty Factor
Maximum Current Sense
Threshold vs Percent of Nominal
Output Voltage (Foldback)
OUTPUT CURRENT (A)
0.001
0
EFFICIENCY (%)
10
30
40
50
100
70
0.01
0.1
1
3728 G01
20
80
90
60
10
FORCED
CONTINUOUS
MODE (PWM)
CONSTANT
FREQUENCY
(BURST DISABLE)
Burst Mode
OPERATION
V
IN
= 15V
V
OUT
= 5V
f = 250kHz
OUTPUT CURRENT (A)
0.001
EFFICIENCY (%)
70
80
10
3728 G02
60
50
0.01
0.1
1
100
90
V
IN
= 10V
V
IN
= 15V
V
IN
= 7V
V
IN
= 20V
V
OUT
= 5V
f = 250kHz
INPUT VOLTAGE (V)
5
EFFICIENCY (%)
70
80
3728 G03
60
50
15
25
35
100
V
OUT
= 5V
I
OUT
= 3A
f = 250kHz
90
INPUT VOLTAGE (V)
05
0
SUPPLY CURRENT (μA)
400
1000
10
20
25
3728 G04
200
800
600
15
30
35
BOTH
CONTROLLERS ON
SHUTDOWN
CURRENT (mA)
0
EXTV
CC
VOLTAGE DROP (mV)
150
200
250
40
3728 G05
100
50
0
10
20
30
50
TEMPERATURE (°C)
–50
INTV
CC
AND EXTV
CC
SWITCH VOLTAGE (V)
4.95
5.00
5.05
25 75
3728 G06
4.90
4.85
–25 0
50 100 125
4.80
4.70
4.75
INTV
CC
VOLTAGE
EXTV
CC
SWITCHOVER THRESHOLD
INPUT VOLTAGE (V)
0
4.8
4.9
5.1
15 25
3728 G07
4.7
4.6
510
20 30 35
4.5
4.4
5.0
INTV
CC
VOLTAGE (V)
I
LOAD
= 1mA
DUTY FACTOR (%)
0
0
V
SENSE
(mV)
25
50
75
20 40 60 80
3728 G08
100
PERCENT ON NOMINAL OUTPUT VOLTAGE (%)
0
V
SENSE
(mV)
40
50
60
100
3728 G09
30
20
0
25
50
75
10
80
70