LTM4601AIV-1#PBF Linear Technology, LTM4601AIV-1#PBF Datasheet - Page 21

• Manufacturer Part Number: LTM4601AIV-1#PBF
• Description: IC DC/DC UMODULE 12A 133-LGA
• Manufacturer: Linear Technology
• Series: µModuler
• Type: Point of Load (POL) Non-Isolatedr

Specifications of LTM4601AIV-1#PBF

• Design Resources: LTM4601A-1 Spice Model
• Output: 0.6 ~ 5 V
• Number Of Outputs: 1
• Power (watts): 60W
• Mounting Type: Surface Mount
• Voltage - Input: 4.5 ~ 20V
• Package / Case: 133-LGA
• 1st Output: 0.6 ~ 5 VDC @ 12A
• Size / Dimension: 0.59" L x 0.59" W x 0.11" H (15mm x 15mm x 2.8mm)
• Power (watts) - Rated: 60W
• Operating Temperature: -40°C ~ 85°C
• Efficiency: 95%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• 3rd Output: -
• 2nd Output: -

APPLICATIONS INFORMATION
Solution
Lower the switching frequency at lower input voltages
to allow for higher duty cycles, and meet the 400ns
minimum off time at 4.5V input voltage. The off time
should be about 500ns with 100ns guard band. The duty
cycle for (3.3V/4.5) ≈ 73%. Frequency = (1 – DC)/t
(1 – 0.73)/500ns = 540kHz. The switching frequency needs
to be lowered to 540kHz at 4.5V input. t
or 1.35μs. The f
the I
fSET
current equates to 38μA with the internal 39.2k.
10V TO 20V
SET
FOR 12V INPUT
pin voltage compliance is 1/3 of V
10μF
V
25V
IN
C2
EFFICIENCY
IMPROVE
5% MARGIN
C1
10μF
25V
100k
392k
1%
R2
R1
CMSSH-3C
V
Figure 16. 5V at 8A Design Without Differential Amplifi er
OUT
100k
R4
ON
= DC/frequency,
SOT-323
PGOOD
MPGM
RUN
COMP
INTV
DRV
CC
CC
SGND
V
IN
LTM4601A-1
IN
OFF
PLLIN
PGND
, and
MARGIN CONTROL
, or
TRACK/SS
f
V
SET
OUT_LCL
MARG0
MARG1
R
100k
The I
A resistor can be placed from V
effective I
pin is 4.5V/3 =1.5V and V
source 14μA into the f
rent to 24μA. This enables the 540kHz operation and the
4.5V to 20V input operation for down converting to 3.3V
output. The frequency will scale from 540kHz to 1.1MHz
over this input range. This provides for an effective output
current of 8A over the input range.
V
fSET
NC3
NC1
NC2
OUT
V
FB
fSET
TRACK/SS CONTROL
C6 100pF
REVIEW TEMPERATURE
LTM4601A/LTM4601A-1
current needs to be 24μA for 540kHz operation.
DERATING CURVE
fSET
8.25k
R
SET
current out of the f
4601A F16
+
SET
C3
100μF
6.3V
SANYO POSCAP
OUT
node and lower the I
V
5V
8A
= 3.3V, therefore 130k will
OUT
SET
OUT
REFER TO
TABLE 2
pin to 24μA. The f
to f
SET
to lower the
fSET
21
4601afb
cur-
SET