LTC3411 Datasheet, PDF (4/20 Pages) Linear Technology – 1.25A, 4MHz, Synchronous Step-Down DC/DC Converter

LTC3411
PI FU CTIO S
PIN
NAME
DESCRIPTION
1
SHDN/R_T Shutdown/Timing Resistor
2
SYNC/MODE Mode Select/Sychronization Pin
3
SGND
Signal Ground
4
SW
Switch Node
5
PGND
Main Power Ground
6
PV_IN
Main Power Supply
7
SV_IN
Signal Power Supply
8
PGOOD
Power Good Pin
9
V_FB
Output Feedback Pin
10
I_TH
Error Amplifier Compensation and Run Pin
NOMINAL (V)
MIN TYP MAX
– 0.3
0.8
SV_IN
0
SV_IN
0
0
PV_IN
0
– 0.3
5.5
2.5
5.5
0
SV_IN
0
0.8
1.0
0
1.5
ABSOLUTE MAX (V)
MIN
MAX
– 0.3
SV_IN + 0.3
– 0.3
SV_IN + 0.3
– 0.3
PV_IN + 0.3
– 0.3
SV_IN + 0.3
– 0.3
6
– 0.3
6
– 0.3
SV_IN + 0.3
– 0.3
SV_IN + 0.3
TYPICAL PERFOR A CE CHARACTERISTICS
Burst Mode Operation
Pulse Skipping Mode
V_OUT
10mV/
DIV
V_OUT
10mV/
DIV
Forced Continuous Mode
V_OUT
10mV/
DIV
I_L1
100mA/
DIV
V_IN = 3.3V
2µs/DIV
V_OUT = 2.5V
I_LOAD = 50mA
CIRCUIT OF FIGURE 7
3411 G01.eps
I_L1
100mA/
DIV
V_IN = 3.3V
2µs/DIV
V_OUT = 2.5V
I_LOAD = 50mA
CIRCUIT OF FIGURE 7
Efficiency vs Load Current
100
Burst Mode
95 ^OPERATION
90
85
PULSE SKIP FORCED CONTINUOUS
80
75
70
V_IN = 3.3V
65
V_OUT = 2.5V
CIRCUIT OF FIGURE 7
60
1
10
100
1000 10000
LOAD CURRENT (mA)
3411 G04
Efficiency vs V_IN
100
I_OUT = 400mA
95
90
I_OUT = 1.25A
85
80
75
70
65 _{VOUT = 2.5V}
CIRCUIT OF FIGURE 7
60
2.5
3.5
4.5
V_IN (V)
3411 G02.eps
I_L1
100mA/
DIV
V_IN = 3.3V
2µs/DIV
V_OUT = 2.5V
I_LOAD = 50mA
CIRCUIT OF FIGURE 7
Load Step
V_OUT
100mV/
DIV
5.5
3411 G05
I_L1
0.5A/
DIV
V_IN = 3.3V
40µs/DIV
V_OUT = 2.5V
I_LOAD = 0.25mA TO 1.25A
CIRCUIT OF FIGURE 7
3411 G03.eps
3411 G06.eps
4
sn3411 3411fs