LTC3890-2 Datasheet, PDF (7/40 Pages) Linear Technology – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

TYPICAL PERFORMANCE CHARACTERISTICS
LTC3890-2
Total Input Supply Current
vs Input Voltage
300
V_OUT = 3.3V
FIGURE 13 CIRCUIT
250
200
300μA LOAD
150
100
NO LOAD
50
0
5 10 15 20 25 30 35 40 45 50 55 60 65
INPUT VOLTAGE (V)
38902 G10
Maximum Current Sense Voltage
vs I_TH Voltage
80
5% DUTY CYCLE
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)
38902 G13
Current Limit
vs Feedback Voltage
80
70
I_LIM = FLOAT
60
50
I_LIM = INTV_CC
40
30
I_LIM = GND
20
10
0
0 100 200 300 400 500 600 700 800
FEEDBACK VOLTAGE (MV)
38902 G16
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
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
38902 G11
SENSE^– Pin Input Bias Current
800
700
600
500
400
300
200
100
0
–100
0
5
10 15 20 25
V_SENSE COMMON MODE VOLTAGE (V)
38902 G14
Quiescent Current vs Temperature
80
V_IN = 12V
75
70
65
60
55
50
45
40
35
30
–75 –50 –25 0 25 50 75 100 125 150
TEMPERATURE (°C)
38902 G17
INTV_CC Line Regulation
5.5
5.0
4.5
4.0
3.5
3.0
I_LOAD = 10mA
0 5 10 15 20 25 30 35 40 45 50 55 60 65
INPUT VOLTAGE (V)
38902 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 (%)
38902 G15
INTV_CC vs Load Current
5.50
V_IN = 12V
5.25
EXTV_CC = 0V
5.00
EXTV_CC = 8.5V
4.75
4.50
EXTV_CC = 5V
4.25
4.00
0
20
40
60
80 100
LOAD CURRENT (mA)
38902 G18
38902f
7