LTM4608EV#PBF Linear Technology, LTM4608EV#PBF Datasheet - Page 15

• Manufacturer Part Number: LTM4608EV#PBF
• Description: IC DC/DC UMODULE 8A 68-LGA
• Manufacturer: Linear Technology
• Series: µModuler
• Type: Point of Load (POL) Non-Isolatedr

Specifications of LTM4608EV#PBF

• Design Resources: LTM4608 Spice Model
• Output: 0.6 ~ 5 V
• Number Of Outputs: 1
• Power (watts): 40W
• Mounting Type: Surface Mount
• Voltage - Input: 2.7 ~ 5.5 V
• Package / Case: 68-LGA
• 1st Output: 0.6 ~ 5 VDC @ 8A
• Size / Dimension: 0.59" L x 0.35" W x 0.11" H (15mm x 9mm x 2.8mm)
• Power (watts) - Rated: 40W
• Operating Temperature: -40°C ~ 85°C
• Efficiency: 95%
• Dc To Dc Converter Type: Step Down
• Pin Count: 68
• Input Voltage: 5.5V
• Output Voltage: 0.6 to 5V
• Switching Freq: 1.7MHz
• Output Current: 8A
• Package Type: LGA
• Output Type: Adjustable
• Switching Regulator: Yes
• Load Regulation: 0.75%
• Line Regulation: 0.2%/V
• Mounting: Surface Mount
• Input Voltage (min): 2.375V
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• 3rd Output: -
• 2nd Output: -
• Lead Free Status / Rohs Status: Compliant

peak noise. Spread spectrum operation is disabled if
CLKIN is tied to ground or if it’s driven by an external
frequency synchronization signal. A capacitor value of
0.01µF must be placed from the PLLLPF pin to ground to
control the slew rate of the spread spectrum frequency
change. Add a control ramp on the TRACK pin with R
and C
for spread spectrum operation.
Output Voltage Tracking
Output voltage tracking can be programmed externally
using the TRACK pin. The output can be tracked up and
down with another regulator. The master regulator’s output
is divided down with an external resistor divider that is the
APPLICATIONS INFORMATION
R
SR
SR
≥
referenced to V
− ln 1−






V
5V
IN
0.592
V
IN
OR APPLY AN EXTERNAL TRACKING RAMP
IN
1
t = –(ln (1 – 0.596/V

 • 500 • C

. Figure 21 shows an example
C
RAMP WITH R
SR
100µs SOFT-START
APPLY A CONTROL
R
TIED TO V
AND DEFAULT
FOR DISABLE
SR
TIE TO V
MASTER
Figure 5. Dual Outputs (3.3V and 1.5V) with Tracking
3.3V
SR
IN
IN
R
10k
R
6.65k
IN
C
SR
) • R
FB3
FB4



WHERE
SR
AND
SR
• C
RUN
RUN
TRACK
TRACK
SR
)
V
SV
SW
RUN
PLLLPF
TRACK
MODE
PHMODE
V
SV
SW
RUN
PLLLPF
TRACK
MODE
PHMODE
CLKOUT GND
CLKOUT GND
IN
IN
IN
IN
SR
LTM4608
LTM4608
CLKIN
CLKIN
same as the slave regulator’s feedback divider to implement
coincident tracking. The LTM4608 uses an accurate 10k
resistor internally for the top feedback resistor. Figure 5
shows an example of coincident tracking:
V
V
reference voltage. When the master’s output is divided down
with the same resistor values used to set the slave’s output,
this resistor divider is connected to the slave’s track pin.
The slave will then 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. Voltage tracking
is disabled when V
Figure 5 will be equal to R
SGND
SGND
PGOOD
PGOOD
TRACK
TRACK
BSEL
BSEL
V
V
MGN
MGN
I
I
Slave = 1+
THM
THM
OUT
OUT
4608 F05
I
I
FB
TH
FB
TH
has a control range of 0V to 0.596V, or the internal
is the track ramp applied to the slave’s track pin.



R
6.65k
R
2.21k
FB2
FB1
C2
100pF
V
IN
R
50k
50k
10k
FB4
TRACK
C1
100µF
C3
22pF

 • V

V
100µF
IN
+
50k
50k
TRACK
FB2
is more than 0.596V. R
MASTER
3.3V
7A
C4
100µF
POSCAP
for coincident tracking.
SLAVE
1.5V
8A
LTM4608
15
FB4
4608fc
in