LTC3866 Datasheet, PDF (6/36 Pages) Linear Technology – Current Mode Synchronous Controller for Sub Milliohm DCR Sensing

LTC3866
Typical Performance Characteristics T_A = 25°C, unless otherwise noted.
Load Step
(Burst Mode^® Operation)
I_LOAD
10A/DIV
1.5A TO 15A
0A
I_L
10A/DIV
0A
V_OUT
100mV/DIV
AC-COUPLED
V_IN = 12V
20µs/DIV
V_OUT = 1.5V
FRONT PAGE CIRCUIT
Load Step
(Continuous Conduction Mode)
I_LOAD
10A/DIV
1.5A TO 15A
0A
Load Step
(Pulse-Skipping Mode)
I_LOAD
10A/DIV
1.5A TO 15A
0A
I_L
10A/DIV
0A
V_OUT
100mV/DIV
AC-COUPLED
3866 G04
V_IN = 12V
20µs/DIV
V_OUT = 1.5V
FRONT PAGE CIRCUIT
I_L
10A/DIV
0A
V_OUT
100mV/DIV
AC-COUPLED
3866 G05
V_IN = 12V
20µs/DIV
V_OUT = 1.5V
FRONT PAGE CIRCUIT
3866 G06
Inductor Current at Light Load
Prebiased Output at 1.2V
CONTINUOUS
CONDUCTION _0A
MODE 5A/DIV
Burst Mode
OPERATION
5A/DIV _0A
PULSE-SKIPPING
MODE 0A
5A/DIV
V_IN = 12V
V_OUT = 1.5V
I_LOAD = 300mA
10µs/DIV
V_OUT
500mV/DIV
0V
V_FB
500mV/DIV
0V
TRACK/SS 500mV/DIV
3866 G07
V_IN = 12V
V_OUT = 1.5V
500µs/DIV
Tracking Up and Down with
TK/SS External Ramp
V_TK/SS
0.2V/DIV
V_OUT
0.5V/DIV
V_TK/SS
V_OUT
0V
3866 G08
V_IN = 12V
V_OUT = 1.5V
1Ω LOAD
2.5ms/DIV
3866 G09
INTV_CC Line Regulation
6
5
4
3
2
1
0
0 5 10 15 20 25 30 35 40
INPUT VOLTAGE (V)
3866 G10
Current Sense Threshold
vs ITH Voltage
40
35
I_LIM = 0V
I_LIM = 1/4 INTV_CC
30
I_LIM = 1/2 INTV_CC
I_LIM = 3/4 INTV_CC
25
I_LIM = INTV_CC
20
15
10
5
0
–5
–10
0
0.25 0.5
0.75 1.0 1.25 1.5 1.75 2.0
V_ITH (V)
3866 G11
Maximum Current Sense Threshold
vs Common Mode Voltage
40
35
I_LIM = INTV_CC
30
I_LIM = 3/4 INTV_CC
25
I_LIM = 1/2 INTV_CC
20
I_LIM = 1/4 INTV_CC
15
10
I_LIM = 0V
5
0
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
V_SENSE COMMON MODE VOLTAGE (V)
3866 G12
3866fa
6