LTC3568_15 Datasheet, PDF (4/18 Pages) Linear Technology – 1.8A, 4MHz, Synchronous Step-Down DC/DC Converter

LTC3568
Typical Performance Characteristics
Burst Mode Operation
V_OUT
10mV/
DIV
S_W
2V/DIV
I_L
500mA/
DIV
V_IN = 3.3V
V_OUT = 2.5V
I_LOAD = 100mA
10µs/DIV
Pulse Skipping Mode
V_OUT
10mV/
DIV
S_W
2V/DIV
3568 G01
I_L
200mA/
DIV
V_IN = 3.3V
V_OUT = 2.5V
I_LOAD = 100mA
2µs/DIV
Forced Continuous Mode
V_OUT
10mV/
DIV
S_W
2V/DIV
3568 G02
I_L
500mA/
DIV
V_IN = 3.3V
V_OUT = 2.5V
I_LOAD = 100mA
2µs/DIV
3568 G03
Efficiency vs Load Current
100
Burst Mode
OPERATION
95
90
85
80
PULSE SKIP _{FORCED CONTINUOUS}
75
V_IN = 3.3V
V_OUT = 2.5V
CIRCUIT OF FIGURE 7
70
1
10
100
1000
10000
LOAD CURRENT (mA)
3568 G04
Efficiency vs V_IN
100
I_OUT = 500mA
95
90
85
I_OUT = 1.8A
80
75
70
65 _{VOUT = 2.5V}
CIRCUIT OF FIGURE 7
60
2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
V_IN (V)
3568 G05
Load Step
V_OUT
100mV/
DIV
I_L
1A/
DIV
V_IN = 3.3V
50µs/DIV
V_OUT = 2.5V
I_LOAD = 180mA TO 1.8A
3568 G06
Load Regulation
0.6
0.5
Burst Mode
0.4
OPERATION
V_IN = 3.3V
V_OUT = 1.8V
0.3
PULSE SKIP
0.2
0.1
0 FORCED
–0.1 ^CONTINUOUS
–0.2
–0.3
–0.4
1
10
100
1000
LOAD CURRENT (mA)
10000
3568 G07
Line Regulation
0.20
V_OUT = 1.8V
0.15
0.10
0.05
I_OUT = 1.8A
0
I_OUT = 500mA
–0.05
–0.10
–0.15
–0.20
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0
V_IN (V)
3568 G08
Frequency vs V_IN
10
8
V_OUT = 1.8V
I_OUT = 1.25A
6 ^{TA = 25°C}
4
2
0
–2
–4
–6
–8
–10
2
3
4
V_IN (V)
5
6
3568 G09
3568fa