Datasheet

LTC3859A
10
3859af
Typical perForMance characTerisTics
Buck Foldback Current Limit
Oscillator Frequency
vs Temperature
Undervoltage Lockout Threshold
vs Temperature
Shutdown (RUN) Threshold
vs Temperature
Charge Pump Charging Current
vs Operating Frequency
Charge Pump Charging Current
vs Switch Voltage
Shutdown Current vs Temperature
Shutdown Current
vs Input Voltage Quiescent Current vs Temperature
TEMPERATURE (°C)
–75
SHUTDOWN CURRENT (µA)
22
20
16
14
10
18
12
8
0 25 50 75 100 125 150–50
3859A G28
–25
V
BIAS
= 12V
V
BIAS
INPUT VOLTAGE (V)
5
SHUTDOWN CURRENT (µA)
25
20
15
5
10
0
20 25 30 35 4010
3859A G29
15
TEMPERATURE (°C)
–75
QUIESCENT CURRENT (µA)
100
90
80
50
60
70
40
0 25 50 75 100 125 150–50
3859A G30
–25
ONE CHANNEL ON
ALL CHANNELS ON
V
BIAS
= 12V
FEEDBACK VOLTAGE (mV)
0
MAXIMUM CURRENT SENSE VOLTAGE (mV)
70
60
50
20
10
30
40
65
55
45
15
5
25
35
0
300 400 500 600 700 800100
3859A G31
200
TEMPERATURE (°C)
–75
FREQUENCY (kHz)
600
550
500
350
400
450
300
0 25 50 75 100 125 150–50
3859A G32
–25
FREQ = INTV
CC
FREQ = GND
TEMPERATURE (°C)
–75
INTV
CC
VOLTAGE (V)
4.4
4.3
4.2
3.6
3.8
4.0
3.4
3.5
3.7
3.9
4.1
0 25 50 75 100 125 150–50
3859A G33
–25
RISING
FALLING
TEMPERATURE (°C)
–75
RUN PIN VOLTAGE (V)
1.40
1.35
1.30
1.20
1.00
1.15
1.10
1.05
1.25
0 25 50 75 100 125 150–50
3859A G34
–25
RUN1 RISING
RUN1 FALLING
RUN2,3 FALLING
RUN2,3 RISING
OPERATING FREQUENCY (kHz)
100
CHARGE PUMP CHARGING CURRENT (µA)
100
80
90
60
70
20
30
0
10
40
50
400 500 600 700 800200
3859A G35
300
–55°C
25°C
150°C
V
BOOST3
= 16V
V
SW3
= 12V
SWITCH VOLTAGE (V)
5
CHARGE PUMP CHARGING CURRENT (µA)
100
80
90
60
70
20
30
0
10
40
50
20 25 30 35 4010
3859A G36
FREQ = 0V
FREQ = INTV
CC
15
V
BOOST3
– V
SW3
= 4V