LTC3727-1 Linear Technology, LTC3727-1 Datasheet - Page 7

• Manufacturer Part Number: LTC3727-1
• Description: 2-Phase Synchronous Step-Down Switching Regulators
• Manufacturer: Linear Technology

TYPICAL PERFOR A CE CHARACTERISTICS
PI FU CTIO S
RUN/SS1, RUN/SS2 (Pins 1, 15): Combination of soft-
start, run control inputs and short-circuit detection timers
(LTC3727 only). A capacitor to ground at each of these
pins sets the ramp time to full output current. Forcing
either of these pins back below 1.0V causes the IC to shut
down the circuitry required for that particular controller.
Latchoff overcurrent protection is also invoked via this pin
as described in the Applications Information section
(LTC3727 only).
35
33
31
29
27
25
U
–50 –25
Current Sense Pin Input Current
vs Temperature
V
OUT
= 5V
U
0
TEMPERATURE ( C)
3.50
3.45
3.35
3.30
3.25
3.20
3.40
25
–50
Undervoltage Lockout
vs Temperature
U
50
–25
75
W
0
TEMPERATURE ( C)
100
3727 G22
25
U
125
50
75
10
6
0
8
4
2
100
–50 –25
EXTV
vs Temperature
3727 G25
125
CC
Switch Resistance
0
TEMPERATURE ( C)
25
SENSE1
Differential Current Comparators. The I
controlled offsets between the SENSE
in conjunction with R
SENSE1
Differential Current Comparators.
V
sensed feedback voltage for each controller from an
external resistive divider across the output.
50
OSENSE1
75
4.5
4.0
3.5
3.0
2.5
2.0
1.0
1.5
0.5
+
–
100
0
, SENSE2
, SENSE2
, V
–50
Shutdown Latch Thresholds
vs Temperature
3727 G23
LTC3727 ONLY
OSENSE2
125
–25
LTC3727/LTC3727-1
0
TEMPERATURE ( C)
+
–
(Pins 4, 12): Receives the remotely-
SENSE
(Pins 2, 14): The (+) Input to the
(Pins 3, 13): The (–) Input to the
THRESHOLD
700
400
300
200
600
500
100
LATCHOFF
25
0
– 50
Oscillator Frequency
vs Temperature
LATCH ARMING
50
set the current trip threshold.
– 25
75
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0
TEMPERATURE ( C)
100
3727 G26
V
25
V
V
PLLFLTR
–
PLLFLTR
PLLFLTR
th
125
and SENSE
50
pin voltage and
= 1.2V
= 5V
= 0V
75
100
+
3727 G24
pins
7
3727f
125