LTC3850-1_15 Datasheet, PDF (7/38 Pages) Linear Technology – Dual, 2-Phase Synchronous Step-Down Switching Controller

LTC3850/LTC3850-1
TYPICAL PERFORMANCE CHARACTERISTICS
Tracking Up and Down
with External Ramp
TK/SS1
TK/SS2
2V/DIV
V_OUT1
3.3V
3Ω LOAD
1V/DIV
V_OUT2
1.8V
1.5Ω LOAD
1V/DIV
10ms/DIV
38501 G10
Quiescent Current
vs Input Voltage without EXTV_CC
5
4
3
2
1
0
5
10
15
20
25
INPUT VOLTAGE (V)
38501 G11
INTV_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)
38501 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
1.5
2
V_ITH (V)
38501 G13
Maximum Current Sense Threshold
vs Common Mode Voltage
80
70
I_LIM = INTV_CC
60
50
I_LIM = FLOAT
40
I_LIM = GND
30
20
10
0
0
1
2
3
4
5
V_SENSE COMMON MODE VOLTAGE (V)
38501 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 (%)
38501 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)
38501 G16
TK/SS Pull-Up Current
vs Temperature
2.00
1.75
1.50
1.25
1.00
–50 –25
0 25 50
TEMPERATURE (°C)
75 100
38501 G17
38501fc
7