ltc1629-6 Linear Technology Corporation, ltc1629-6 Datasheet - Page 7

• Manufacturer Part Number: ltc1629-6
• Description: Polyphase, Synchronous Step-down Switching Regulator
• Manufacturer: Linear Technology Corporation

RUN/SS (Pin 1): Combination of Soft-Start, Run Control
Input and Short-Circuit Detection Timer. A capacitor 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
Differential Current Comparators. The I
built-in offsets between SENSE
conjunction with R
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
3.50
3.45
3.40
3.35
3.30
3.25
3.20
0
TEMPERATURE ( C)
–50
Undervoltage Lockout
vs Temperature
25
–25
SENSE
+
U
50
(Pins 2,14): The (+) Input to the
0
TEMPERATURE ( C)
set the current trip threshold.
75
W
25
100
1629 G23
50
–
U
125
and SENSE
75
TH
100
pin voltage and
1629 G26
10
6
8
4
2
0
125
–50 –25
EXTV
vs Temperature
+
pins in
CC
Switch Resistance
0
TEMPERATURE ( C)
25
SENSE1
Differential Current Comparators.
EAIN (Pin 4): Input to the Error Amplifier that compares
the feedback voltage to the internal 0.6V reference voltage.
This pin is normally connected to a resistive divider from
the output of the differential amplifier (DIFFOUT).
PLLFLTR (Pin 5): The Phase-Locked Loop’s Low Pass
Filter is tied to this pin. Alternatively, this pin can be driven
with an AC or DC voltage source to vary the frequency of
the internal oscillator.
50
75
–
, SENSE2
100
1629 G24
4.5
3.5
3.0
2.5
2.0
1.0
4.0
1.5
0.5
125
0
–50
Shutdown Latch Thresholds
vs Temperature
–25
–
(Pins 3, 13): The (–) Input to the
350
200
300
250
150
100
50
0
0
TEMPERATURE ( C)
– 50
Oscillator Frequency
vs Temperature
THRESHOLD
LATCHOFF
25
– 25
LATCH ARMING
50
0
TEMPERATURE ( C)
LTC1629-6
75
V
25
V
PLLFLTR
PLLFLTR
100
50
1629 G27
= 2.4V
= 0V
125
75
100
1629 G25
16296f
7
125