Datasheet

LTC3773
5
3773fb
LOAD CURRENT (A)
0
ΔV
OUT
(mV)
NORMALIZED ΔV
OUT
(%)
–10
–5
5
0
3773 G04
–15
–20
–25
–0.4
–0.2
0.2
0.0
–0.6
–0.8
–1.0
5
10
15
20
V
IN
= 12V, V
CC
= 5V, V
OUT
= 2.5V
CONTINUOUS MODE
DISCONTINUOUS MODE
Burst Mode OPERATION
TYPICAL PERFORMANCE CHARACTERISTICS
Effi ciency vs Load Current,
Shutdown CH2 and CH3
CHANNEL 1 LOAD CURRENT (A)
V
IN
= 12V, V
CC
= 5V, V
OUT1
= 2.5V
f
SW
= 220kHz
20
CHANNEL 1 EFFICIENCY (%)
POWER LOSS (mW)
40
30
10
60
80
70
50
90
100
0.001 0.01 0.1 1 10 100
3773 G01
0
1
10
100
1000
10000
0.1
EFFICIENCY
POWER LOSS
CONTINUOUS
MODE
DISCONTINUOUS
MODE
Burst Mode
OPERATION
Effi ciency vs V
IN
Shutdown CH2 and CH3 Load Regulation
V
IN
(V)
0
CHANNEL 1 EFFICIENCY (%)
POWER LOSS (W)
90
95
100
20
3773 G03
85
80
75
2.4
3.2
4.0
1.6
0.8
0.0
5
10
15
25
PLLFLTR = 5V
f
SW
= 560kHz
PLLFLTR FLOATS
f
SW
= 400kHz
PLLFLTR = 0V
f
SW
= 220kHz
EFFICIENCY
POWER LOSS
V
CC
= 5V, V
OUT1
= 2.5V, I
OUT1
= 5A
SHUTDOWN CH2 AND CH3
CHANNEL 1 LOAD CURRENT (A)
V
IN
= 12V, V
CC
= 5V, V
OUT1
= 2.5V
V
OUT2
= 1.8V (NO LOAD), V
OUT3
= 1.2V (NO LOAD)
f
SW
= 220kHz
20
CHANNEL 1 EFFICIENCY (%)
POWER LOSS (mW)
40
30
10
60
80
70
50
90
100
0.001 0.01 0.1 1 10 100
3773 G02
0
1
10
100
1000
10000
0.1
EFFICIENCY
POWER LOSS
DISCONTINUOUS
MODE
Burst Mode
OPERATION
CONTINUOUS
MODE
V
IN
(V)
0
ΔV
OUT
(mV)
NOMALIZED ΔV
OUT
(mV/V)
0.5
1.5
1.0
2.0
2.5
20
3773 G05
–0.5
–1.0
0
–1.5
–2.0
–2.5
0.2
0.6
0.4
0.8
1.0
–0.2
–0.4
0
–0.6
–0.8
–1.0
5
10
15
25
V
CC
= 5V, V
OUT
= 2.5V, I
OUT
= 5A
Current Limit vs V
IN
V
IN
(V)
0
MAXIMUM LOAD CURRENT (A)
15
20
25
20
3773 G06
10
5
0
5
10
15
25
V
CC
= 5V, V
OUT
= 2.5V, f
SW
= 220kHz
R
SENSE
= 3mΩ
R
SENSE
= 5mΩ
Effi ciency vs Load Current,
Power-Up CH2 and CH3
Line Regulation