LTC3853_15 Datasheet, PDF (5/36 Pages) Linear Technology – Triple Output, Multiphase Synchronous Step-Down Controller

TYPICAL PERFORMANCE CHARACTERISTICS
LTC3853
Efficiency vs Output Current
and Mode
100
90
80
70
BURST
60
50
DCM _CCM
40
30
20
10
0
0.01
V_IN = 12V
V_OUT = 1.8V
FIGURE 15 MODIFIED
WITH DCR SENSING
0.1
1
LOAD CURRENT (A)
10
3853 G01
Efficiency vs Output Current
and Mode
100
90
80
BURST
70
60
50
CCM
40
DCM
30
20
10
0
0.01
V_IN = 12V
V_OUT = 3.3V
FIGURE 15 MODIFIED
WITH DCR SENSING
0.1
1
LOAD CURRENT (A)
10
3853 G02
Efficiency and Power Loss
vs Input Voltage
100
2.0
95
1.8
1.6
90
EFFICIENCY
1.4
85
1.2
80
1.0
75
POWER LOSS
0.8
0.6
70
65
V_OUT = 3.3V
I_OUT = 2A
0.4
FIGURE 15 MODIFIED _0.2
WITH DCR SENSING
60
0
0
5 10 15 20 25 30
INPUT VOLTAGE (V)
3853 G03
Load Step
(Burst Mode Operation)
I_LOAD
2A/DIV
I_L
2A/DIV
V_OUT
100mV/DIV
AC COUPLED
V_IN = 12V
40µs/DIV
V_OUT = 3.3V
I_LOAD = 0A TO 3A
FIGURE 15 CIRCUIT
3853 G04
Load Step
(Forced Continuous Mode)
I_LOAD
2A/DIV
I_L
2A/DIV
V_OUT
100mV/DIV
AC COUPLED
V_IN = 12V
40µs/DIV
V_OUT = 3.3V
I_LOAD = 0A TO 3A
FIGURE 15 CIRCUIT
3853 G05
Load Step
(Pulse Skip Mode)
I_LOAD
2A/DIV
I_L
2A/DIV
V_OUT
100mV/DIV
AC COUPLED
V_IN = 12V
40µs/DIV
V_OUT = 3.3V
I_LOAD = 0A TO 3A
FIGURE 15 CIRCUIT
3853 G06
Inductor Current at Light Load
FORCED
CONTINUOUS
MODE
2A/DIV
Burst Mode
OPERATION
2A/DIV
PULSE SKIPPING
MODE
2A/DIV
V_IN = 12V
1µs/DIV
V_OUT = 1.8V
I_LOAD = 100mA
FIGURE 15 CIRCUIT
3853 G07
For more information www.linear.com/LTC3853
3853fc
5