LTM4614IV#PBF Linear Technology, LTM4614IV#PBF Datasheet - Page 11

• Manufacturer Part Number: LTM4614IV#PBF
• Description: IC UMODULE DC/DC DUAL 4A 144LGA
• Manufacturer: Linear Technology
• Series: µModuler
• Type: Point of Load (POL) Non-Isolatedr

Specifications of LTM4614IV#PBF

• Design Resources: LTM4614 Spice Model
• Output: 0.8 ~ 5 V
• Number Of Outputs: 2
• Power (watts): 12W
• Mounting Type: Surface Mount
• Voltage - Input: 2.38 ~ 5.5 V
• Package / Case: 144-LGA
• 1st Output: 0.8 ~ 5 VDC @ 4A
• 2nd Output: 0.8 ~ 5 VDC @ 4A
• Size / Dimension: 0.59" L x 0.59" W x 0.11" H (15mm x 15mm x 2.8mm)
• Power (watts) - Rated: 12W
• Operating Temperature: -40°C ~ 125°C
• Efficiency: 95%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• 3rd Output: -

APPLICATIONS INFORMATION
TRACK1 is the track ramp applied to the slave’s track pin.
TRACK1 applies the track reference for the slave output up
to the point of the programmed value at which TRACK1
proceeds beyond the 0.8V reference value. The TRACK1
pin must go beyond the 0.8V to ensure the slave output
has reached its fi nal value.
Ratiometric tracking can be achieved by a few simple
calculations and the slew rate value applied to the master’s
TRACK pin. As mentioned above, the TRACK pin has a
control range from 0V to 0.8V. The control ramp slew rate
applied to the master’s TRACK pin is directly equal to the
master’s output slew rate in Volts/Time.
The equation:
where MR is the master’s output slew rate and SR is the
slave’s output slew rate in Volts/Time. When coincident
tracking is desired, then MR and SR are equal, thus R
is equal to 4.99k. R
where V
tor, and V
R
MR
SR
TA
• 4.99k = R
=
FB
TRACK
4.99k
is the feedback voltage reference of the regula-
V
FB
is 0.8V. Since R
+
R
TB
0.8V
V
TA
FB
FB
is derived from equation:
–
V
TRACK
R
TB
TB
is equal to the 4.99k top
Figure 3. Output Voltage Coincident Tracking
TB
TIME
feedback resistor of the slave regulator in equal slew rate
or coincident tracking, then R
V
Figure 3 shows the output voltage tracking waveform for
coincident tracking.
In ratiometric tracking, a different slew rate maybe desired
for the slave regulator. R
slower than MR. Make sure that the slave supply slew rate
is chosen to be fast enough so that the slave output voltage
will reach it fi nal value before the master output.
For example, MR = 2.5V/ms and SR = 1.8V/1ms. Then
R
output must be greater than the slave output for the
tracking to work. Output load current must be present
for tracking to operate properly during power down.
Power Good
PGOOD1 and PGOOD2 are open-drain pins that can be
used to monitor valid output voltage regulation. These pins
monitor a ±7.5% window around the regulation point.
COMP Pin
This pin is the external compensation pin. The module has
already been internally compensated for all output voltages.
Table 4 is provided for most application requirements.
The Linear Technology μModule Power Design Tool will
be provided for other control loop optimization.
TRACK
TB
MASTER OUTPUT
SLAVE OUTPUT
= 6.98k. Solve for R
. Therefore R
4614 F03
TB
= 4.99k and R
TA
TB
to equal to 3.24k. The master
can be solved for when SR is
TA
is equal to R
TA
LTM4614
= 10k in Figure 2.
FB
with V
11
4614fa
FB
=