ltc3729euh-trpbf Linear Technology Corporation, ltc3729euh-trpbf Datasheet - Page 7

• Manufacturer Part Number: ltc3729euh-trpbf
• Description: 550khz, Polyphase, High Efficiency, Synchronous Step-down Switching Regulator
• Manufacturer: Linear Technology Corporation

RUN/SS (Pin 1/Pin 28): Combination of Soft-Start, Run
Control Input and Short-Circuit Detection Timer. A capaci-
tor to ground at this pin sets the ramp time to full current
output. Forcing this pin below 0.8V causes the IC to shut
down all internal circuitry. All functions are disabled in
shutdown.
SENSE1
Input to the Differential Current Comparators. The I
voltage and built-in offsets between SENSE
PI FU CTIO S
TYPICAL PERFOR A CE CHARACTERISTICS
35
33
31
29
27
25
U
–50 –25
Current Sense Pin Input Current
vs Temperature
V
OUT
+
, SENSE2
= 5V
U
0
TEMPERATURE ( C)
3.50
3.45
3.30
3.20
3.40
3.35
3.25
25
–50
Undervoltage Lockout
vs Temperature
+
U
–25
50
(Pins 2,14/Pins 30, 12): The (+)
75
0
G Package/UH Package
TEMPERATURE ( C)
W
100
25
3729
G23
U
125
50
75
100
–
10
6
8
4
2
0
and SENSE
3729
–50 –25
EXTV
vs Temperature
G26
125
CC
TH
Switch Resistance
pin
0
TEMPERATURE ( C)
+
25
pins in conjunction with R
old.
SENSE1
Input to the Differential Current Comparators.
EAIN (Pin 4/Pin 1): Input to the Error Amplifier that
compares the feedback voltage to the internal 0.8V refer-
ence voltage. This pin is normally connected to a resistive
divider from the output of the differential amplifier
(DIFFOUT).
50
75
–
, SENSE2
100
4.5
4.0
3.5
3.0
2.5
2.0
1.0
1.5
0.5
0
3729
–50
Shutdown Latch Thresholds
vs Temperature
G24
125
–25
–
0
TEMPERATURE ( C)
(Pins 3, 13/Pins 31, 11): The (–)
700
400
600
500
300
200
100
0
THRESHOLD
– 50
LATCHOFF
25
SENSE
Oscillator Frequency
vs Temperature
LATCH ARMING
– 25
50
set the current trip thresh-
75
0
TEMPERATURE ( C)
V
V
100
25
V
PLLFLTR
PLLFLTR
PLLFLTR
3729
LTC3729
G27
50
125
= 1.2V
= 2.4V
= 0V
75
sn3729 3729fas
100
3729
7
G25
125