Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF HTML

TC1313-1H1EMF Datasheet(PDF) 20 Page - Microchip Technology

Part No. TC1313-1H1EMF
Description  500 mA Synchronous Buck Regulator, 300 mA LDO
Download  32 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  MICROCHIP [Microchip Technology]
Homepage  http://www.microchip.com
Logo 

TC1313-1H1EMF Datasheet(HTML) 20 Page - Microchip Technology

Zoom Inzoom in Zoom Outzoom out
 20 / 32 page
background image
TC1313
DS21974B-page 20
© 2009 Microchip Technology Inc.
5.5
Inductor Selection
For
most
applications,
a
4.7 µH
inductor
is
recommended to minimize noise. There are many
different magnetic core materials and package options
to select from. That decision is based on size, cost and
acceptable radiated energy levels. Toroid and shielded
ferrite pot cores will have low radiated energy but tend
to be larger and more expensive. With a typical
2.0 MHz switching frequency, the inductor ripple
current can be calculated based on the following
formulas.
EQUATION 5-2:
Duty cycle represents the percentage of switch-on
time.
EQUATION 5-3:
The inductor ac ripple current can be calculated using
the following relationship:
EQUATION 5-4:
Solving for
ΔIL = yields:
EQUATION 5-5:
When considering inductor ratings, the maximum DC
current rating of the inductor should be at least equal to
the maximum buck regulator load current (IOUT1), plus
one half of the peak-to-peak inductor ripple current (1/
2*
ΔIL). The inductor DC resistance can add to the
buck converter I2R losses. A rating of less than 200 m
Ω
is recommended. Overall efficiency will be improved by
using lower DC resistance inductors.
TABLE 5-2:
TC1313 RECOMMENDED
INDUCTOR VALUES
5.6
Thermal Calculations
5.6.1
BUCK REGULATOR OUTPUT
(VOUT1)
The TC1313 is available in two different 10-pin
packages (MSOP and 3x3 DFN). By calculating the
power dissipation and applying the package thermal
resistance, (
θJA), the junction temperature is estimated.
The maximum continuous junction temperature rating
for the TC1313 is +125°C.
To quickly estimate the internal power dissipation for
the switching buck regulator, an empirical calculation
using measured efficiency can be used. Given the
measured efficiency (Section 2.0 “Typical Perfor-
mance Curves”
), the internal power dissipation is
estimated below.
EQUATION 5-6:
The first term is equal to the input power (definition of
efficiency, POUT/PIN = Efficiency). The second term is
equal to the delivered power. The difference is internal
power dissipation. This estimate assumes that most of
the power lost is internal to the TC1313. There is some
percentage of power lost in the buck inductor, with very
little loss in the input and output capacitors.
DutyCycle
V
OUT
V
IN
-------------
=
T
ON
DutyCycle
1
F
SW
----------
×
=
Where:
FSW
=
Switching Frequency
V
L
L
ΔI
L
Δt
--------
×
=
Where:
VL
=
voltage across the inductor
(VIN – VOUT)
Δt
=
on-time of P-channel MOSFET
ΔI
L
V
L
L
------
Δt
×
=
Part
Number
Value
(µH)
DCR
Ω
(max)
MAX
IDC (A)
Size
WxLxH (mm)
Coiltronics®
SD10
2.2
0.091
1.35 5.2, 5.2, 1.0 max.
SD10
3.3
0.108
1.24 5.2, 5.2, 1.0 max.
SD10
4.7
0.154
1.04 5.2, 5.2, 1.0 max.
Coiltronics
SD12
2.2
0.075
1.80 5.2, 5.2, 1.2 max.
SD12
3.3
0.104
1.42 5.2, 5.2, 1.2 max.
SD12
4.7
0.118
1.29 5.2, 5.2, 1.2 max.
Sumida Corporation®
CMD411
2.2
0.116
0.950 4.4, 5.8, 1.2 max.
CMD411
3.3
0.174 0.770 4.4, 5.8, 1.2 max.
CMD411
4.7
0.216 0.750 4.4, 5.8, 1.2 max.
Coilcraft®
1008PS
4.7
0.35
1.0
3.8, 3.8, 2.74 max.
1812PS
4.7
0.11
1.15 5.9, 5.0, 3.81 max.
V
OUT1
I
OUT1
×
Efficiency
-------------------------------------
⎝⎠
⎛⎞
V
OUT1
I
OUT1
×
()
P
Dissipation
=


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32 


Datasheet Download




Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn