LTC3899_15 Datasheet, PDF (10/38 Pages) Linear Technology – 60V Low IQ, Triple Output, Buck/Buck/Boost Synchronous Controller

LTC3899
Typical Performance Characteristics
Shutdown Current vs Temperature
8
V_BIAS = 12V
7
6
5
4
3
2
1
0
-75 -50 -25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G28
Buck Foldback Current
100
90
80
70
60
50
40
30
20
10
0
0 100 200 300 400 500 600 700 800
FEEDBACK VOLTAGE (mV)
3899 G31
BOOST3 Charge Pump Output
Voltage vs SW3 Voltage
10
9
8
7
6
5
4
3
150°C
25°C
2
–55°C
1 ^{FREQ = 350kHz}
10MΩ LOAD BETWEEN BOOST3 AND SW3
0
5 10 15 20 25 30 35 40 45 50 55 60 65
SW3 VOLTAGE (V)
3899 G34
Shutdown Current vs
Input Voltage
14
12
10
8
6
4
2
0
0 5 10 15 20 25 30 35 40 45 50 55 60 65
INPUT VOLTAGE (V)
3899 G29
Oscillator Frequency vs
Temperature
600
550
FREQ = INTV_CC
500
450
400
FREQ = GND
350
300
-75 -50 -25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G32
BOOST3 Charge Pump Charging
Current vs Frequency
100
90
80
– 55°C
70
25°C
60
50
40
150°C
30
20
10 ^VBOOST3 ^{= 16.5V}
V_SW3 = 12V
0
100 200 300 400 500 600 700 800
OPERATING FREQUENCY (kHz)
3899 G35
10
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Quiescent Current vs Temperature
80
V_BIAS = 12V
70 ^{ONE CHANNEL ON}
Burst Mode OPERATION
60
DRVSET = 70kΩ
50
40
DRVSET = INTV_CC
30
DRVSET = GND
20
10
0
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G30
Undervoltage Lockout Threshold
vs Temperature
8
RISING
7.5
7
DRVSET = INTV_CC
6.5
FALLING
6
5.5
5
4.5
RISING
DRVSET = GND
4
3.5
FALLING
3
-75 -50 -25 0 25 50 75 100 125 150
TEMPERATURE (°C)
3899 G33
BOOST3 Charge Pump Charging
Current vs Switch Voltage
120
110
– 55°C
100
90
25°C
80
V_BOOST3 – V_SW3 = 4.5V
70
150°C
60
50
40
V_BOOST3 – V_SW3 = 7.0V _{–55°C}
30
25°C ^150°C
20
10
FREQ = 350kHz
0
0 5 10 15 20 25 30 35 40 45 50 55 60 65
SW3 VOLTAGE (V)
3899 G36
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