LTC3646-1_15 Datasheet, PDF (6/28 Pages) Linear Technology – 40V, 1A Synchronous Step-Down Converter

LTC3646/LTC3646-1
TYPICAL PERFORMANCE CHARACTERISTICS
T_A = 25°C, SVIN/PVIN = 12V, f_O = 1MHz unless otherwise noted.
No Load Quiescent Current vs
Temperature, Burst Mode Operation
200
Bottom Switch Current Limit
vs Temperature
1.5
180
1.4
160
1.3
140
1.2
120
1.1
100
–40 –20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
36461 G10
Output Voltage vs Time,
Burst Mode Operation
1.0
–40 –20 0 20 40 60 80 100 120 140
TEMPERATURE (°C)
36461 G11
Start-Up from Shutdown,
Burst Mode Operation
Load Regulation
1.6
V_OUT = 5V
1.2
0.8
0.4
0
–0.4
0
FORCED CONTINUOUS
Burst Mode OPERATION
0.2
0.4
0.6
0.8
1
LOAD CURRENT (A)
36461 G12
Start-Up from Shutdown,
Forced Continuous Mode
SW
10V/DIV
I_L
250mA/DIV
V_OUT
20mV/DIV
AC-COUPLED
V_IN = 12V
V_OUT = 5V
I_LOAD = 20mA
2µs/DIV
RUN
5V/DIV
I_L
250mA/DIV
V_OUT
5V/DIV
36461 G13
I_LOAD = 25mA ^100µs/DIV
RUN
5V/DIV
I_L
250mA/DIV
V_OUT
5V/DIV
36461 G14
I_LOAD = 25mA ^100µs/DIV
36461 G15
Load Step, Burst Mode Operation
Load Step,
Forced Continuous Operation
I_LOAD
1A/DIV
I_L
1A/DIV
V_OUT
AC-COUPLED
100mV/DIV
V_OUT = 1.2V
40µs/DIV
50mA to 1A STEP
f_O = 2.25MHz
R_COMP = 200kΩ
C_COMP = 33pF
C_F = 10pF
C_OUT = 15µF
I_LOAD
1A/DIV
I_L
1A/DIV
V_OUT
AC-COUPLED
100mV/DIV
36461 G16
V_OUT = 1.2V
10µs/DIV
50mA to 1A STEP
f_O = 2.25MHz
R_COMP = 200kΩ
C_COMP = 33pF
C_F = 10pF
C_OUT = 15µF
36461 G17
6
For more information www.linear.com/LTC3646
I_Q Shutdown vs Supply and
Temperature
60
V_IN = 40V
V_IN = 12V
50
40
30
20
10
0
–40 –20 0
20 40 60 80 100 120 140
TEMPERATURE (°C)
36461 G18
36461fb