LTC3728_15 Datasheet, PDF (5/36 Pages) Linear Technology – Dual, 550kHz, 2-Phase Synchronous Step-Down Switching Regulator

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