Datasheet

LTC3822-1
4
38221f
TYPICAL PERFORMANCE CHARACTERISTICS
Effi ciency/Power Loss
vs Load Current
Load Step (Continuous Mode)
Regulated Feedback Voltage
vs Temperature
Undervoltage Lockout Threshold
vs Temperature
Shutdown (RUN) Threshold
vs Temperature
Maximum Current Sense
Threshold vs Temperature
Oscillator Frequency
vs Temperature
T
A
= 25°C unless otherwise noted.
TEMPERATURE (°C)
–50
0.596
FEEDBACK VOLTAGE (V)
0.597
0.598
0.600
0.599
0.601
0.602
100
38212 G06
0.603
0.604
050
TEMPERATURE (°C)
–60
2.15
2.20
2.25
INPUT VOLTAGE (V)
2.30
2.35
2.40
2.45
–20 20
60
100
38221 G07
2.50
2.55
–40 0
40
80
V
IN
RISING
V
IN
FALLING
TEMPERATURE (°C)
–60
1.00
RUN VOLTAGE (V)
1.05
–20 20
60
100
38221 G08
1.15
1.10
1.20
–40 0
40
80
TEMPERATURE (°C)
–60
115
120
MAXIMUM CURRENT SENSE THRESHOLD (mV)
125
130
135
–20 20
60
100
3822 G09
–40 0
40
80
IPRG = FLOAT
TEMPERATURE (°C)
–60
–10
–8
–6
NORMALIZED FREQUENCY SHIFT (%)
–4
–2
0
4
–20 20
60
100
38221 G10
8
2
6
10
–40 0
40
80
LOAD CURRENT (mA)
10
40
EFFICIENCY (%)
POWER LOSS (W)
50
60
70
80
100 1000 10000
38221 G01
30
20
10
0
90
100
1
10
0.1
0.01
0.001
100
FIGURE 10 CIRCUIT
Burst Mode OPERATION
PULSE SKIPPING
CONTINUOUS MODE
EFFICIENCY
POWER LOSS
V
IN
= 3.3V, V
OUT
= 1.8V
Load Step (Pulse Skip Mode)
V
OUT
AC COUPLED
200mV/DIV
INDUCTOR
CURRENT
2A/DIV
FIGURE 10 CIRCUIT
50µs/DIV
38221 G02
V
OUT
AC COUPLED
200mV/DIV
INDUCTOR
CURRENT
2A/DIV
FIGURE 10 CIRCUIT
50µs/DIV
38221 G04
Load Step (Burst Mode Operation)
V
OUT
AC COUPLED
200mV/DIV
INDUCTOR
CURRENT
2A/DIV
FIGURE 10 CIRCUIT
50µs/DIV
38221 G05