LTC3789 Datasheet, PDF (7/28 Pages) Linear Technology – High Efficiency, Synchronous, 4-Switch Buck-Boost Controller

LTC3789
Typical Performance Characteristics T_A = 25°C unless otherwise noted.
Maximum Current Sense
Threshold vs Duty Factor (Boost)
150
140
130
120
110
100
90
80
70
60
50
0
20
40
60
80
DUTY FACTOR (%)
100
3789 G19
Maximum Current Sense
Threshold vs Duty Factor (Buck)
150
140
130
120
110
100
90
80
70
60
50
0
20
40
60
80
DUTY FACTOR (%)
100
3789 G20
Maximum Current Limit
vs Temperature
150
BOOST
140
130
120
110
100
BUCK
90
80
70
60
–50 –30 –10 10 30 50 70 90 110 130
TEMPERATURE (°C)
3789 G21
Peak Current Threshold
vs V_ITH (Boost)
200
150
100
50
0
–50
–100
–150
–200
0 0.5 1 1.5 2
V_ITH (V)
2.5 3
3789 G22
Valley Current Threshold
vs V_ITH (Buck)
200
150
100
50
0
–50
–100
0
0.5
1
1.5
V_ITH (V)
2
2.5
3789 G23
Current Foldback Limit
160
140
120
100
80
60
40
20
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
V_FB (V)
3789 G24
Load Step
Load Step
Load Step
V_OUT
200mV/DIV
V_OUT
200mV/DIV
V_OUT
200mV/DIV
I_L
2A/DIV
400µs/DIV
V_IN = 6V
V_OUT = 12V
LOAD STEP = 200mA TO 2A
3789 G25
I_L
2A/DIV
400µs/DIV
V_IN = 12V
V_OUT = 12V
LOAD STEP = 300mA TO 3A
3789 G26
I_L
2A/DIV
400µs/DIV
V_IN = 18V
V_OUT = 12V
LOAD STEP = 300mA TO 3A
3789 G27
3789f
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