LTC3856 Datasheet, PDF (7/40 Pages) Linear Technology – 2-Phase Synchronous Step-Down DC/DC Controller with Diffamp

Typical Performance Characteristics
LTC3856
Load Step without AVP
V_OUT
50mV/DIV
Load Step with AVP
108mV
V_OUT
50mV/DIV
50A
I_L
20A/DIV
25A
V_IN = 12V
V_OUT = 1.5V
100µs/DIV
50A
3856 G07
I_L
20A/DIV
25A
V_IN = 12V
V_OUT = 1.5V
100µs/DIV
54mV
3856 G07a
INTV_CC Line Regulation
5.25
5.00
4.75
4.50
4.25
4.00
3.75
3.50
3.25
3.00
0
5 10 15 20 25 30 35 40
INPUT VOLTAGE (V)
3856 G09
Maximum Current Sense Voltage
vs Duty Cycle
100
90
80
I_LIM = INTV_CC
70
60
I_LIM = FLOAT
50
40
I_LIM = GND
30
20
10
0
0 10 20 30 40 50 60 70 80 90 100
DUTY CYCLE (%)
3856 G12
Current Sense Threshold
vs I_TH Voltage
80
I_LIM = INTV_CC
60
40
I_LIM = FLOAT
20
I_LIM = GND
0
–20
–40
0
0.5
1
1.5
2
V_ITH (V)
3856 G10
Maximum Current Sense Voltage
vs Feedback Voltage
(Current Foldback)
100
90
80
I_LIM = INTV_CC
70
60
I_LIM = FLOAT
50
40
I_LIM = GND
30
20
10
0
0 0.1 0.2 0.3 0.4 0.5 0.6
FEEDBACK VOLTAGE (V)
3856 G13
Quiescent Current vs Input
Voltage without EXTV_CC
4.5
4.3
4.1
3.9
3.7
3.5
3.3
3.1
2.9
2.7
2.5
5
10 15 20 25 30 35 40
INPUT VOLTAGE (V)
3856 G08
Maximum Current Sense Threshold
vs Common Mode Voltage
80
70
I_LIM = INTV_CC
60
I_LIM = FLOAT
50
40
30
I_LIM = GND
20
10
0
0
1
2
3
4
5
VSENSE COMMON MODE VOLTAGE (V)
3856 G11
TK/SS Pull-Up Current
vs Temperature
1.5
1.4
1.3
1.2
1.1
1.0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3856 G14
3856f