Datasheet

7
LTC3727/LTC3727-1
3727fc
Undervoltage Lockout
vs Temperature
Shutdown Latch Thresholds
vs Temperature
TYPICAL PERFOR A CE CHARACTERISTICS
UW
TEMPERATURE (°C)
–50
UNDERVOLTAGE LOCKOUT (V)
3.40
3.45
3.50
25 75
3727 G25
3.35
3.30
–25 0
50 100 125
3.25
3.20
TEMPERATURE (°C)
–50 –25
0
SHUTDOWN LATCH THRESHOLDS (V)
0.5
1.5
2.0
2.5
75 10050
4.5
3727 G26
1.0
0 25 125
3.0
3.5
4.0
LATCH ARMING
LTC3727 ONLY
LATCHOFF
THRESHOLD
UU
U
PI FU CTIO S
RUN/SS1, RUN/SS2 (Pins 1, 15/Pins 28, 13): Combina-
tion 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).
SENSE1
+
, SENSE2
+
(Pins 2, 14/Pins 30, 12): The (+)
Input to the Differential Current Comparators. The I
TH
pin
voltage and controlled offsets between the SENSE
–
and
SENSE
+
pins in conjunction with R
SENSE
set the current
trip threshold.
SENSE1
–
, SENSE2
–
(Pins 3, 13/Pins 31, 11): The (–)
Input to the Differential Current Comparators.
V
OSENSE1
, V
OSENSE2
(Pins 4, 12/Pins 1, 9): Receives the
remotely-sensed feedback voltage for each controller from
an external resistive divider across the output.
Current Sense Pin Input Current
vs Temperature
EXTV
CC
Switch Resistance
vs Temperature
Oscillator Frequency
vs Temperature
TEMPERATURE (°C)
–50 –25
25
CURRENT SENSE INPUT CURRENT (μA)
29
35
0
50
75
3727 G22
27
33
31
25
100
125
V
OUT
= 5V
TEMPERATURE (°C)
–50 –25
0
EXTV
CC
SWITCH RESISTANCE (Ω)
4
10
0
50
75
3727 G23
2
8
6
25
100
125
TEMPERATURE (°C)
–50
400
500
700
25 75
3727 G24
300
200
–25 0
50 100 125
100
0
600
FREQUENCY (kHz)
V
PLLFLTR
= 5V
V
PLLFLTR
= 1.2V
V
PLLFLTR
= 0V
G Package/UH Package