Datasheet

LTC3859A
8
3859af
Typical perForMance characTerisTics
Load Step (Boost)
Burst Mode Operation
Load Step (Boost)
Pulse-Skipping Mode
Load Step (Boost)
Forced Continuous Mode
Inductor Current at Light Load
(Boost) Soft Start-Up (Boost)
Boost Regulated Feedback
Voltage vs Temperature
Efficiency and Power Loss
vs Output Current (Boost)
Efficiency
vs Output Current (Boost) Efficiency vs Input Voltage (Boost)
OUTPUT CURRENT (A)
0.0001
EFFICIENCY (%)
POWER LOSS (mW)
100
90
70
50
30
10
80
60
40
20
0
10000
100
1
1000
10
0.1
1 100.01
3859A G10
0.10.001
FIGURE 12 CIRCUIT
V
IN
= 5V, V
OUT
= 10V, V
BIAS
= V
IN
FCM EFFICIENCY
PULSE-SKIPPING
EFFICIENCY
BURST LOSS
BURST
EFFICIENCY
FCM LOSS
PULSE-SKIPPING
LOSS
OUTPUT CURRENT (A)
0.0001
EFFICIENCY (%)
100
90
70
50
30
10
80
60
40
20
0
1 100.01
3859A G11
0.10.001
V
IN
= 5V
FIGURE 12 CIRCUIT
V
BIAS
= V
IN
V
OUT
= 10V
V
IN
= 8V
INPUT VOLTAGE (V)
2
EFFICIENCY (%)
100
99
97
95
91
92
93
98
96
94
90
6 7 8 9 1043
3859A G12
5
FIGURE 12 CIRCUIT
V
BIAS
= V
IN
V
OUT
= 10V
I
LOAD
= 2A
200µs/DIV
V
OUT
100mV/
DIV
AC-
COUPLED
I
L
5A/DIV
3859A G13
V
OUT
= 10V
V
IN
= 5V
FIGURE 12 CIRCUIT
200µs/DIV
V
OUT
100mV/DIV
AC-COUPLED
I
L
5A/DIV
3859A G14
V
OUT
= 10V
V
IN
= 5V
FIGURE 12 CIRCUIT
200µs/DIV
V
OUT
100mV/DIV
AC-COUPLED
I
L
5A/DIV
3859A G15
V
OUT
= 10V
V
IN
= 5V
FIGURE 12 CIRCUIT
2µs/DIV
FORCED
CONTINUOUS
MODE
Burst Mode
OPERATION
5A/DIV
PULSE-
SKIPPING
MODE
3859A G16
V
OUT
= 10V
V
IN
= 7V
I
LOAD
= 1mA
FIGURE 12 CIRCUIT
20ms/DIV
V
OUT3
2V/DIV
GND
3859A G17
V
IN
= 5V
FIGURE 12 CIRCUIT
TEMPERATURE (°C)
–75
REGULATED FEEDBACK VOLTAGE (V)
1.212
1.209
1.203
1.191
1.194
1.197
1.206
1.200
1.188
0 25 50 75 150120100–50
3859A G18
–25