Linear Technology Analog Devices LTM4636-1, Manual

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LTM4636
15
4636f
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applicaTions inForMaTion
accurate 4.99k resistor internally for the top feedback
resistor. Figure 5 shows an example of coincident tracking.
V
OUT(SLAVE)
= 1 +
4.99k
R
TA

 

• V
TRACK
V
TRACK
is the track ramp applied to the slave’s track pin.
V
TRACK
has a control range of 0V to 0.6V, or the internal
reference voltage. When the master’s output is divided
down with the same resistor values used to set the slave’s
output, then the slave will coincident track with the master
until it reaches its final value. The master will continue
to its final value from the slave’s regulation point (see
Figure 6). Voltage tracking is disabled when V
TRACK
is
more than 0.6V. R
TA
in Figure 5 will be equal to R
FB
for
coincident tracking.
The TRACK/SS pin of the master can be controlled by an
external ramp or the soft-start function of that regulator can
be used to develop that master ramp. The LTM4636 can
be used as a master by setting the ramp rate on its track
pin using a soft-start capacitor. A 1.25µA current source
is used to charge the soft-start capacitor. The following
equation can be used:
t
SOFT-START
= 0.6V •
C
SS
1.25µA

 

Figure 4. Phase Selection Examples
LTM4636
180 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
3/4 INTV
CC
LTM4636
240 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
3/4 INTV
CC
LTM4636
300 PHASE
MODE_PLLIN
PHMODE
4636 F04
CLKOUT
V
OUT
3/4 INTV
CC
LTM4636
0 PHASE
MODE_PLLIN
PHMODE
R2
10k
R1
30.1k
CLKOUT
V
OUT
LTM4636
0 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
LTM4636
90 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
LTM4636
180 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
LTM4636
270 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
3/4 INTV
CC
INTV
CC
LTM4636
60 PHASE
SIX PHASE
FOUR PHASE
LTM4636
0 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
LTM4636
120 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
LTM4636
240 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
THREE PHASE
LTM4636
0 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
LTM4636
180 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
FLOAT INTV
CC
TWO PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
3/4 INTV
CC
LTM4636
120 PHASE
MODE_PLLIN
PHMODE
CLKOUT
V
OUT
3/4 INTV
CC
V
OUT
PHASE
0
0
0
0
0
CLKOUT
PHASE
90
90
120
60
180
PHMODE
(V)
0
1/4 INTV
CC
FLOAT
3/4 INTV
CC
INTV
CC
PHASE SELECTION