LTM4608EV#PBF Linear Technology, LTM4608EV#PBF Datasheet - Page 13

• 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

APPLICATIONS INFORMATION
provide more output current without increasing input and
output voltage ripple. The CLKIN pin allows the LTC4608
to synchronize to an external clock (between 0.75MHz
and 2.25MHz) and the internal phase-locked loop allows
the LTM4608 to lock onto CLKIN’s phase as well. The
CLKOUT signal can be connected to the CLKIN pin of the
following LTM4608 stage to line up both the frequency
and the phase of the entire system. Tying the PHMODE
pin to SV
difference (between CLKIN and CLKOUT) of 180°, 120° or
90° respectively, which corresponds to a 2-phase, 3-phase
or 4-phase operation. A total of 6 phases can be cascaded
to run simultaneously with respect to each other by pro-
gramming the PHMODE pin of each LTM4608 to different
levels. For a 6-phase example in Figure 2, the 2nd stage
that is 120° out of phase from the 1st stage can generate
a 240° (PHMODE = 0) CLKOUT signal for the 3rd stage,
V
+
LTC6908-2
IN
OUT1
OUT2
, SGND or SV
CLKIN
PHMODE
PHASE 1
0
CLKOUT
CLKIN
PHMODE
CLKIN
PHMODE
+120
PHASE 1
PHASE 4
IN
90
0
/2 (floating) generates a phase
CLKOUT
CLKOUT
CLKIN
PHMODE
PHASE 3
120
+120
+120
CLKOUT
CLKIN
PHMODE
CLKIN
PHMODE
+120
PHASE 5
PHASE 8
S
VIN
120
210
CLKOUT
CLKOUT
Figure 3. 12-Phase Operation
CLKIN
PHMODE
Figure 2. 6-Phase Operation
PHASE 5
S
S
+120
+120
VIN
VIN
240
CLKOUT
CLKIN
PHMODE
CLKIN
PHMODE
PHASE 12
PHASE 9
+180
240
330
CLKOUT
CLKOUT
which then can generate a CLKOUT signal that’s 420°,
or 60° (PHMODE = SV
CLKIN input, the next two stages can shift 120° (PHMODE
= 0) for each to generate a 300° signal for the 6th stage.
Finally, the signal with a 60° phase shift on the 6th stage
(PHMODE is floating) goes back to the 1st stage. Figure
3 shows the configuration for a 12 phase configuration
A multiphase power supply significantly reduces the
amount of ripple current in both the input and output
capacitors. The RMS input ripple current is reduced by,
and the effective ripple frequency is multiplied by, the
number of phases used (assuming that the input voltage
is greater than the number of phases used times the output
voltage). The output ripple amplitude is also reduced by
the number of phases used.
CLKIN
PHMODE
PHASE 2
+180
+180
(420)
60
CLKOUT
CLKIN
PHMODE
CLKIN
PHMODE
PHASE 3
PHASE 6
(420)
(510)
+120
150
60
CLKOUT
CLKOUT
CLKIN
PHMODE
+120
+120
PHASE 4
IN
180
) for the 4th stage. With the 60°
CLKOUT
CLKIN
PHMODE
CLKIN
PHMODE
PHASE 10
PHASE 7
180
270
+120
CLKOUT
CLKOUT
CLKIN
PHMODE
+120
+120
LTM4608
PHASE 6
300
CLKOUT
CLKIN
PHMODE
CLKIN
PHMODE
PHASE 11
PHASE 2
(390)
300
30
CLKOUT
CLKOUT
4608 F02
13
4608fc
4608 F02
4608 F03