LTC3834-1 Datasheet, PDF (4/28 Pages) Linear Technology – 30μA IQ Synchronous Step-Down Controller

LTC3834-1
TYPICAL PERFOR A CE CHARACTERISTICS T_A = 25ºC, unless otherwise noted.
Efficiency and Power Loss vs
Output Current
100
Burst Mode OPERATION
90
FORCED CONTINUOUS MODE
PULSE SKIPPING MODE
80 _{VIN = 12V}
70 ^VOUT ^{= 3.3V}
10000
1000
60
100
50
40
10
30
20
1
10
0
0.000001
FIGURE 10 CIRCUIT
0.1
0.0001
0.01
1
OUTPUT CURRENT (A)
38341 G01
Load Step (Burst Mode Operation)
Efficiency vs Load Current
100
V_IN = 12V
V_IN = 5V
90 _{VOUT = 3.3V}
80
70
60
50
40
0.000001
FIGURE 10 CIRCUIT
0.0001
0.01
OUTPUT CURRENT (A)
1
38341 G02
Load Step (Forced Continuous
Mode)
Efficiency vs Input Voltage
98
96
94
92
90
88
86
84
V_OUT = 3.3V
82
FIGURE 10 CIRCUIT
80
0 5 10 15 20 25 30
INPUT VOLTAGE (V)
35 40
38341 G03
Load Step (Pulse Skipping Mode)
V_OUT
100mV/DIV
AC
COUPLED
V_OUT
100mV/DIV
AC
COUPLED
V_OUT
100mV/DIV
AC
COUPLED
IL
2A/DIV
IL
2A/DIV
IL
2A/DIV
20μs/DIV
V_OUT = 3.3V
FIGURE 10 CIRCUIT
38341 G04
Inductor Current at Light Load
FORCED
CONTINUOUS
MODE
2A/DIV
Burst Mode
OPERATION
20μs/DIV
V_OUT = 3.3V
FIGURE 10 CIRCUIT
Soft Start-Up
38341 G05
V_OUT
1V/DIV
20μs/DIV
V_OUT = 3.3V
FIGURE 10 CIRCUIT
38341 G06
Tracking Start-Up
MASTER
2V/DIV
V_OUT
2V/DIV
PULSE
SKIPPING
MODE
2μs/DIV
V_OUT = 3.3V
I_LOAD = 100μA
FIGURE 10 CIRCUIT
38341 G07
20ms/DIV
FIGURE 10 CIRCUIT
38341 G08
20ms/DIV
FIGURE 10 CIRCUIT
38341 G09
38341f
4