LTC3859_15 Datasheet, PDF (10/42 Pages) Linear Technology – Low IQ, Triple Output, Buck/Buck/Boost Synchronous Controller

LTC3859
TYPICAL PERFORMANCE CHARACTERISTICS
Shutdown Current vs Temperature
22
20
18
16
14
12
10
8
–45 –20
5 30 55 80
TEMPERATURE (°C)
105 130
3859 G28
Buck Foldback Current Limit
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
0 100 200 300 400 500 600 700 800
FEEDBACK VOLTAGE (mV)
3859 G31
Shutdown (RUN) Threshold
vs Temperature
1.40
1.35
1.30
1.25
RUN2,3 FALLING
1.20
RUN2,3 RISING
RUN1 RISING
1.15 RUN1 FALLING
1.10
1.05
1.00
–45 –20
5 30 55 80
TEMPERATURE (°C)
105 130
3859 G34
10
Shutdown Current
vs Input Voltage
25
20
15
10
5
0
5 10 15 20 25 30 35 40
INPUT VOLTAGE (V)
3859 G29
Oscillator Frequency
vs Temperature
600
FREQ = INTV_CC
550
500
450
400
FREQ = GND
350
300
–45 –20
5 30 55 80
TEMPERATURE (°C)
105 130
3859 G32
Charge Pump Charging Current
vs Operating Frequency
100
V_BOOST3 = 16V
90 _{VSW3 = 12V}
80
–45°C
70
25°C
60
50
40
130°C
30
20
10
0
100 200 300 400 500 600 700 800
OPERATING FREQUENCY (kHz)
3859 G35
Quiescent Current vs Temperature
100
90
80
ALL CHANNELS ON
70
60
ONE CHANNEL ON
50
40
–45 –20
5 30 55 80
TEMPERATURE (°C)
105 130
3859 G30
Undervoltage Lockout Threshold
vs Temperature
4.4
4.3
4.2
RISING
4.1
4.0
3.9
FALLING
3.8
3.7
3.6
3.5
3.4
–45 –20
5 30 55 80
TEMPERATURE (°C)
105 130
3859 G33
Charge Pump Charging Current
vs Switch Voltage
100
V_BOOST3 – V_SW3 = 4V
90
80
FREQ = 0V
70
60
FREQ = INTV_CC
50
40
30
20
10
0
5 10 15 20 25 30 35 40
SWITCH VOLTAGE (V)
3859 G36
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