LTC3729_15 Datasheet, PDF (5/30 Pages) Linear Technology – 550kHz, PolyPhase, High Efficiency, Synchronous Step-Down Switching Regulator

TYPICAL PERFORMANCE CHARACTERISTICS
LTC3729
Efficiency vs Output Current
(Figure 12)
100
80
V_IN = 5V
V_IN = 8V
60
V_IN = 12V
V_IN = 20V
40
20
0
0.1
V_OUT = 3.3V
V_EXTVCC = 5V
I_OUT = 20A
f = 250kHz
1
10
100
OUTPUT CURRENT (A)
3729 G01
Supply Current vs Input Voltage
and Mode
1000
800
600
ON
400
200
SHUTDOWN
0
0 5 10 15 20 25 30 35
INPUT VOLTAGE (V)
3729 G04
Internal 5V LDO Line Reg
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)
3729 G07
Efficiency vs Output Current
(Figure 12)
100
V_EXTVCC = 5V
90
V_EXTVCC = 0V
80
70
60
V_OUT = 3.3V
f = 250kHz
50
1
10
100
OUTPUT CURRENT (A)
3729 G02
EXTV_CC Voltage Drop
250
200
150
100
50
0
0
10
20
30
40
50
CURRENT (mA)
3729 G05
Maximum Current Sense Threshold
vs Duty Factor
75
50
25
0
0
20
40
60
80
100
DUTY FACTOR (%)
3729 G08
Efficiency vs Input Voltage
(Figure 12)
100
V_OUT = 3.3V
V_EXTVCC = 5V
I_OUT = 20A
f = 250kHz
90
80
70
5
10
15
V_IN (V)
INTV_CC and EXTV_CC Switch
Voltage vs Temperature
5.05
INTV_CC VOLTAGE
5.00
20
3729 G03
4.95
4.90
4.85
4.80
EXTV_CC SWITCHOVER THRESHOLD
4.75
4.70
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3729 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 (%)
3729 G09
3729fb
5