LTC3853_15 Datasheet, PDF (6/36 Pages) Linear Technology – Triple Output, Multiphase Synchronous Step-Down Controller

LTC3853
TYPICAL PERFORMANCE CHARACTERISTICS
Prebiased Output at 2V
50ms/DIV
V_OUT
1V/DIV
V_TK/SS
500mV/DIV
V_FB
500mV/DIV
Coincident Tracking
RUN1
2V/DIV
V_OUT1,2,3
1V/DIV
3853 G08
V_IN = 12V
V_OUT1 = 3.3V
V_OUT2 = 2.5V
V_OUT3 = 1.8V
10ms/DIV
Tracking Up and Down
with External Ramp
TK/SS1
TK/SS2
TK/SS3
2V/DIV
V_OUT1,2,3
1V/DIV
3853 G09
V_IN = 12V
V_OUT1 = 3.3V
V_OUT2 = 2.5V
V_OUT3 = 1.8V
5ms/DIV
3853 G10
Quiescent Current
vs Input Voltage Without EXTV_CC
6.0
5.5
5.0
4.5
4.0
5
10
15
20
INPUT VOLTAGE (V)
25
3853 G11
Internal V_CC Line Regulation
5.25
5.00
4.75
4.50
4.25
4.00
3.75
3.50
0
5
10
15
20
25
INPUT VOLTAGE (V)
3853 G12
Current Sense Threshold
vs I_TH Voltage
80
I_LIM = INTV_CC
60
I_LIM = FLOAT
40
20
I_LIM = GND
0
–20
–40
0
0.5
1
V_ITH (V)
1.5
2
3853 G13
Maximum Current Sense Threshold
vs Common Mode Voltage
80
70
I_LIM = INTV_CC
60
I_LIM = FLOAT
50
40
I_LIM = GND
30
20
10
0
0
1
2
3
4
5
V_SENSE COMMON MODE VOLTAGE (V)
3853 G14
Maximum Current Sense
Threshold 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
20
40
60
80 100
DUTY CYCLE (%)
3853 G15
Maximum Current Sense Voltage vs
Feedback Voltage (Current Foldback)
80
I_LIM = INTV_CC
70
60
50
I_LIM = FLOAT
40
30
I_LIM = GND
20
10
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
FEEDBACK VOLTAGE (V)
3853 G16
3853fc
6
For more information www.linear.com/LTC3853