LTC3649
TA = 25°C, unless otherwise noted.
TYPICAL PERFORMANCE CHARACTERISTICS
RDS(ON) vs Temperature
Transient Response, CCM
Transient Response, Burst Mode
200
160
120
80
V
V
OUT
OUT
MTOP
MBOT
100mV/DIV
100mV/DIV
AC-COUPLED
AC-COUPLED
I
I
L
2A/DIV
L
2A/DIV
40
3649 G08
3649 G09
20µs/DIV
20µs/DIV
= 5V
V
OUT
R
= 24V, V
= 5V
V
= 24V, V
OUT
OUT
ITH
IN
OUT
IN
0
I
= 0A TO 4A, L = 2.2µH, f = 1MHz
I
= 0.2A TO 4A, L = 2.2µH, f = 1MHz
SW
SW
–55 –35 –15
5
25 45 65 85 105 125
= 4kΩ, C = 2.2nF, C
= 47pF
R
= 4kΩ, C = 2.2nF, C
= 47pF
ITHP
ITH
ITH
= 2× 47µF
ITHP
ITH
FC MODE, C
BURST MODE, C
= 2× 47µF
TEMPERATURE (°C)
OUT
OUT
3649 G07
Switching Frequency/Period
vs RT
Switching Frequency
vs Temperature
Output Regulation with VIN Slew
1010
1005
1000
995
3.0
2.5
2.0
1.5
1.0
0.5
0
3500
3000
2500
2000
1500
1000
500
I
L
1A/DIV
FREQUENCY
V
PERIOD
OUT
2V/DIV
V
IN
50V/DIV
990
3649 G12
10ms/DIV
= 12V TO 60V, V = 5V
V
IN
OUT
985
0
I
= 0A, L = 2.2µH, f = 2.25MHz
SW
OUT
–55 –35 –15
5
25 45 65 85 105 125
0
50 100 150 200 250 300 350
R
= 4kΩ, C = 2.2nF, C
= 47pF
ITHP
ITH
ITH
= 2× 47µF
FC MODE, C
TEMPERATURE (°C)
RT RESISTOR (kΩ)
OUT
3649 G11
3649 G10
Continuous Conduction Mode
Operation
Run Rising Threshold
vs Temperature
Burst Mode Operation
1.210
1.205
1.200
1.195
1.190
1.185
1.180
I
I
L
L
1A/DIV
1A/DIV
SW
10V/DIV
SW
10V/DIV
3649 G13
3649 G14
2µs/DIV
500ns/DIV
V
OUT
R
= 24V, V
= 5V
V
OUT
R
= 24V, V
= 5V
OUT
IN
OUT
IN
I
= 100mA, L = 2.2µH, f = 1MHz
I
= 0A, L = 2.2µH, f = 1MHz
SW
SW
–55 –35 –15
5
25 45 65 85 105 125
= 4kΩ, C = 2.2nF, C
= 47pF
= 4kΩ, C = 2.2nF, C
= 47pF
ITH
ITH
OUT
ITHP
= 2× 47µF
ITH
ITH
ITHP
BURST MODE, C
FC MODE, C
= 2× 47µF
TEMPERATURE (°C)
OUT
3649 G15
3649fb
5
For more information www.linear.com/LTC3649
Linear [ Linear ]
