LTC3786_15 Datasheet, PDF (5/34 Pages) Linear Technology – Low IQ Synchronous Boost Controller

Typical Performance Characteristics
LTC3786
Efficiency and Power Loss
vs Output Current
100
10000
90
80
1000
70
60
50
40
30
20
10
0
0.01
100
V_IN = 12V
V_OUT = 24V
FIGURE 8 CIRCUIT ₁₀
CCM EFFICIENCY
CMM LOSS
BURST EFFICIENCY
BURST LOSS
1
PULSE-SKIPPING EFFICIENCY
PULSE-SKIPPING LOSS
0.1
0.1
1
10
OUTPUT CURRENT (A)
3786 G01
Efficiency and Power Loss
vs Output Current
100
10000
90
80
BURST
EFFICIENCY
70
60
BURST
LOSS
1000
100
50
40
10
30
20
10
0
0.00001 0.0001 0.001
V_IN = 12V
V_OUT = 24V
1
Burst Mode OPERATION
FIGURE 8 CIRCUIT
0.1
0.01 0.1 1 10
OUTPUT CURRENT (A)
3786 G02
Efficiency vs Input Voltage
100
I_LOAD = 2A
99 ^{FIGURE 8 CIRCUIT}
98
V_OUT = 12V
97
V_OUT = 24V
96
Load Step
Forced Continuous Mode
LOAD STEP
2A/DIV
INDUCTOR
CURRENT
5A/DIV
V_OUT
500mV/DIV
95
94
93
0
5
10
15
20
25
INPUT VOLTAGE (V)
3786 G03
V_IN = 12V
V_OUT = 24V
200µs/DIV
LOAD STEP FROM 200mA TO 2.5A
FIGURE 8 CIRCUIT
Load Step
Burst Mode Operation
LOAD STEP
2A/DIV
INDUCTOR
CURRENT
5A/DIV
V_OUT
500mV/DIV
3786 G04
V_IN = 12V
V_OUT = 24V
200µs/DIV
LOAD STEP FROM 200mA TO 2.5A
FIGURE 8 CIRCUIT
Load Step
Pulse-Skipping Mode
Inductor Current at Light Load
Soft Start-Up
LOAD STEP
2A/DIV
INDUCTOR
CURRENT
5A/DIV
V_OUT
500mV/DIV
V_IN = 12V
200µs/DIV
V_OUT = 24V
LOAD STEP FROM 200mA TO 2.5A
FIGURE 8 CIRCUIT
FORCED
CONTINUOUS
MODE
Burst Mode
OPERATION
5A/DIV
PULSE-
SKIPPING MODE
3786 G06
V_IN = 12V
5µs/DIV
V_OUT = 24V
I_LOAD = 200µA
FIGURE 8 CIRCUIT
V_OUT
5V/DIV
3786 G07
0V
V_IN = 12V
20ms/DIV
V_OUT = 24V
FIGURE 8 CIRCUIT
3786 G05
3786 G08
3786fa
5