LTC3822-1 Datasheet, PDF (4/24 Pages) Linear Technology – No RSENSE, Low Input Voltage, Synchronous Step-Down DC/DC Controller

LTC3822-1
TYPICAL PERFORMANCE CHARACTERISTICS T_A = 25°C unless otherwise noted.
Efficiency/Power Loss
vs Load Current
100
V_IN = 3.3V, V_OUT = 1.8V
90
80
EFFICIENCY
70
Load Step (Continuous Mode)
100
V_OUT
10 _{AC COUPLED}
200mV/DIV
Load Step (Pulse Skip Mode)
V_OUT
AC COUPLED
200mV/DIV
60
1
50
40
30
20
10
0
10
POWER LOSS
INDUCTOR
0.1
CURRENT
2A/DIV
FIGURE 10 CIRCUIT
0.01
Burst Mode OPERATION
PULSE SKIPPING
CONTINUOUS MODE _0.001
100
1000
10000
LOAD CURRENT (mA)
38221 G01
50µs/DIV
FIGURE 10 CIRCUIT
INDUCTOR
CURRENT
2A/DIV
38221 G02
50µs/DIV
FIGURE 10 CIRCUIT
38221 G04
Load Step (Burst Mode Operation)
V_OUT
AC COUPLED
200mV/DIV
INDUCTOR
CURRENT
2A/DIV
50µs/DIV
FIGURE 10 CIRCUIT
38221 G05
Regulated Feedback Voltage
vs Temperature
0.604
0.603
0.602
0.601
0.600
0.599
0.598
0.597
0.596
–50
0
50
TEMPERATURE (°C)
100
38212 G06
Undervoltage Lockout Threshold
vs Temperature
2.55
2.50
V_IN RISING
2.45
2.40
2.35
2.30
V_IN FALLING
2.25
2.20
2.15
–60 –40 –20 0 20 40 60
TEMPERATURE (°C)
80 100
38221 G07
Shutdown (RUN) Threshold
vs Temperature
1.20
1.15
Maximum Current Sense
Threshold vs Temperature
135
IPRG = FLOAT
130
1.10
125
1.05
120
1.00
–60 –40 –20 0 20 40 60
TEMPERATURE (°C)
80 100
38221 G08
115
–60 –40 –20 0 20 40 60
TEMPERATURE (°C)
80 100
3822 G09
Oscillator Frequency
vs Temperature
10
8
6
4
2
0
–2
–4
–6
–8
–10
–60 –40 –20 0 20 40 60
TEMPERATURE (°C)
80 100
38221 G10
38221f
4