LTC3890 Datasheet, PDF (6/36 Pages) Linear Technology – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

LTC3890
TYPICAL PERFORMANCE CHARACTERISTICS
Total Input Supply Current vs
Input Voltage
300
250
200
300μA
150
100
NO LOAD
50
0
5 10 15 20 25 30 35 40 45 50 55 60 65
INPUT VOLTAGE (V)
3890 G10
Maximum Current Sense Voltage
vs I_TH Voltage
80
60
PULSE SKIPPING MODE
40
Burst Mode
OPERATION
20
I_LIM = GND
0
I_LIM = INTV_CC
–20
I_LIM = FLOAT
FORCED CONTINUOUS MODE
–40
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
V_ITH (V)
3890 G13
EXTV_CC Switchover and INTV_CC
Voltages vs Temperature
6.0
5.8
5.6
5.4
5.2
INTV_CC
5.0
EXTV_CC RISING
4.8
4.6
EXTV_CC FALLING
4.4
4.2
4.0
–45 –20
5 30 55 80 105 130
TEMPERATURE (°C)
3890 G11
SENSE^– Pin Input Bias Current
0
–100
–200
–300
–400
–500
–600
–700
–800
0
5 10 15 20 25
V_SENSE COMMON MODE VOLTAGE (V)
3890 G14
INTV_CC Line Regulation
5.2
5.1
5.0
4.9
4.8
5 10 15 20 25 30 35 40 45 50 55 60 65
INPUT VOLTAGE (V)
3890 G12
Maximum Current Sense
Threshold vs Duty Cycle
80
70
I_LIM = FLOAT
60
50
I_LIM = INTV_CC
40
I_LIM = GND
30
20
0 10 20 30 40 50 60 70 80 90 100
DUTY CYCLE (%)
3890 G15
Foldback Current Limit
80
I_LIM = FLOAT
70
60
I_LIM = INTV_CC
50
40
30
I_LIM = GND
20
10
0
0 100 200 300 400 500 600 700 800
FEEDBACK VOLTAGE (MV)
3890 G16
6
Quiescent Current vs Temperature
80
75
70
65
60
55
50
45
40
–45 –20
5 30 55 80
TEMPERATURE (°C)
105 130
3890 G17
INTV_CC vs Load Current
5.20
V_IN = 12V
5.15
5.10
EXTV_CC = 0V
5.05
EXTV_CC = 8.5V
5.00
4.95
0 20 40 60 80 100 120 140 160 180 200
LOAD CURRENT (mA)
3890 G18
3890f