Datasheet

LTC3861-1
5
38611fa
For more information www.linear.com/LTC3861-1
Typical perFormance characTerisTics
Load Step Transient Response
(4-Phase Using TDA21220
DrMOS)
Line Step Transient Response
(2-Phase Using LTC4449)
Efficiency vs Load Current
Feedback Voltage V
FB
vs Temperature
Load Step Transient Response
(Single Phase Using LTC4449)
Load Step Transient Response
(2-Phase Using D12S1R845A
Power Block)
Load Step Transient Response
(3-Phase Using FDMF6707B
DrMOS)
LOAD CURRENT (A)
0
EFFICIENCY (%)
90
95
85
80
75
70
65
60
20 30 50
10
40 60 70
55
50
100
38611 G07
V
IN
= 12V
V
OUT
= 1.2V
2-PHASE, LTC4449
f
SW
= 300kHz
20µs/DIV
38611 G01
V
OUT
50mV/DIV
AC-COUPLED
V
IN
= 12V
V
OUT
= 1.2V
I
LOAD
STEP = 3A TO 18A TO 3A
f
SW
= 300kHz
I
L
10A/DIV
40µs/DIV
38611 G02
I
LOAD
20A/DIV
V
OUT
50mV/DIV
AC-COUPLED
V
IN
= 12V
V
OUT
= 1.2V
I
LOAD
STEP = 0A TO 20A TO 0A
f
SW
= 300kHz
I
L1
10A/DIV
I
L2
10A/DIV
50µs/DIV
38611 G03
V
OUT
50mV/DIV
AC-COUPLED
V
IN
= 12V
V
OUT
= 1.2V
I
LOAD
STEP = 4A TO 20A TO 4A
f
SW
= 400kHz
I
LOAD
20A/DIV
50µs/DIV
38611 G04
V
OUT
100mV/DIV
AC-COUPLED
V
IN
= 12V
V
OUT
= 1.2V
I
LOAD
STEP = 0A TO 30A TO 0A
f
SW
= 500kHz EXTERNAL CLOCK
I
L2
10A/DIV
I
L1
10A/DIV
I
L3
10A/DIV
40µs/DIV
38611 G05
V
OUT
50mV/DIV
AC-COUPLED
V
IN
= 12V
V
OUT
= 1V
I
LOAD
STEP = 40A TO 80A TO 40A
f
SW
= 500kHz EXTERNAL CLOCK
I
LOAD
40A/DIV
20µs/DIV
38611 G06
V
IN
10V/DIV
V
OUT
50mV/DIV
AC-COUPLED
V
IN
= 7V TO 14V IN 20µs
V
OUT
= 1.2V
I
LOAD
= 20A
f
SW
= 300kHz
I
L1
10A/DIV
I
L2
10A/DIV
Load Step Transient Response
(2-Phase Using LTC4449)
TEMPERATURE (°C)
–50
REGULATED V
FB
VOLTAGE (V)
600.50
600.75
600.25
600.00
0 25 75
–25
50 100 125 150
599.75
599.50
601.00
38611 G09
Efficiency vs Load Current
0
86
90
70
82
78
20 40
10 90
30 50
80
60 100
74
70
94
88
92
84
80
76
72
96
38611 G08
LOAD CURRENT (A)
EFFICIENCY (%)
V
IN
= 12V, V
OUT
= 1V
4-PHASE TDA21220 DrMOS
f
SW
= 500kHz EXTERNAL CLOCK