LTC3858-1 Linear Technology Corporation, LTC3858-1 Datasheet - Page 5

• Manufacturer Part Number: LTC3858-1
• Description: Dual 2-Phase Synchronous Step-Down Controller
• Manufacturer: Linear Technology Corporation

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TYPICAL PERFORMANCE CHARACTERISTICS
100mV/DIV
COUPLED
2A/DIV
94
92
88
86
84
80
98
96
90
82
V
OUT
AC
0
Effi ciency vs Input Voltage
I
L
Load Step (Pulse-Skipping Mode)
V
FIGURE 12 CIRCUIT
OUT
5
= 3.3V
10
100
20
10
90
80
70
60
50
40
30
0.0001
INPUT VOLTAGE (V)
0
15
Effi ciency and Power Loss vs
Output Current
FIGURE 12 CIRCUIT
V
V
IN
OUT
20μs/DIV
= 12V
20
0.001
= 3.3V
FIGURE 12 CIRCUIT
V
I
OUT
OUT
25
OUTPUT CURRENT (A)
= 4A
= 3.3V
0.01
30
35
3858 G03
0.1
3858 G06
40
Burst Mode
OPERATION
PULSE-
SKIPPING
MODE
FORCED
CONTINUOUS
MODE
100mV/DIV
CONTINUOUS
COUPLED
1
OPERATION
Burst Mode
2A/DIV
SKIPPING
V
3858 G01
FORCED
OUT
2A/DIV
PULSE
AC
MODE
MODE
I
L
10
Load Step (Burst Mode Operation)
V
FIGURE 12 CIRCUIT
1000
100
10
1
0.1
10000
OUT
Inductor Current at Light Load
V
I
FIGURE 12 CIRCUIT
LOAD
OUT
= 3.3V
= 3.3V
= 200μA
20μs/DIV
2μs/DIV
100
20
10
3858 G04
90
80
70
60
50
40
30
0.0001
0
Effi ciency vs Load Current
3858 G07
V
IN
0.001
100mV/DIV
= 5V
COUPLED
2A/DIV
Soft-Start
FIGURE 12 CIRCUIT
OUTPUT CURRENT (A)
V
V
OUT
IN
AC
I
0.01
L
= 12V
Load Step
(Forced Continuous Mode)
V
FIGURE 12 CIRCUIT
OUT
= 3.3V
V
FIGURE 12 CIRCUIT
0.1
OUT
20ms/DIV
= 3.3V
LTC3858-1
1
20μs/DIV
3858 G02
10
3858 G08
V
2V/DIV
V
2V/DIV
38581f
5
3858 G05
OUT2
OUT1