LTC3858 Linear Technology, LTC3858 Datasheet - Page 5

• Manufacturer Part Number: LTC3858
• Description: Synchronous Step-Down Controller
• Manufacturer: Linear Technology

Typical perForMance characTerisTics
100mV/DIV
COUPLED
2A/DIV
94
92
88
86
84
80
98
96
90
82
V
OUT
AC-
0
I
Efficiency vs Input Voltage
L
Load Step (Pulse-Skipping Mode)
V
FIGURE 12 CIRCUIT
OUT
5
= 3.3V
10
INPUT VOLTAGE (V)
100
90
80
70
60
50
40
30
20
10
0.0001
15
0
Efficiency and Power Loss
vs Output Current
FIGURE 12 CIRCUIT
V
V
20µs/DIV
IN
OUT
20
= 12V
0.001
FIGURE 12 CIRCUIT
V
I
= 3.3V
OUT
OUT
25
= 4A
OUTPUT CURRENT (A)
= 3.3V
30
0.01
35
3858 G03
3858 G06
0.1
40
100mV/DIV
Burst Mode
OPERATION
PULSE-
SKIPPING
MODE
FORCED
CONTINUOUS
MODE
CONTINUOUS
COUPLED
OPERATION
Burst Mode
2A/DIV
SKIPPING
1
FORCED
V
PULSE-
OUT
AC-
2A/DIV
MODE
MODE
I
3858 G01
L
Load Step (Burst Mode Operation)
V
FIGURE 12 CIRCUIT
OUT
10
Inductor Current at Light Load
V
I
FIGURE 12 CIRCUIT
LOAD
10000
1000
100
10
1
0.1
OUT
= 3.3V
= 3.3V
= 200µA
20µs/DIV
2µs/DIV
100
3858 G04
90
80
70
60
50
40
30
20
10
0.0001
0
3858 G07
Efficiency vs Output Current
V
IN
100mV/DIV
COUPLED
0.001
= 5V
2A/DIV
V
Soft-Start
FIGURE 12 CIRCUIT
OUT
AC-
OUTPUT CURRENT (A)
V
I
L
IN
0.01
Load Step
(Forced Continuous Mode)
V
FIGURE 12 CIRCUIT
= 12V
OUT
= 3.3V
V
FIGURE 12 CIRCUIT
0.1
OUT
www.DataSheet4U.com
20ms/DIV
= 3.3V
20µs/DIV
1
LTC3858
3858 G02
10
3858 G08
3858 G05
V
2V/DIV
V
2V/DIV
3858fa

OUT2
OUT1