Bill of Materials
2
Bill of Materials
Designator
Description
Part Number
Qty
Manufacturer
U1
Synchronous Buck Regulator
LM20133
1
Texas Instruments
C
IN
47 µF, 1210, X5R, 6.3 V
GRM32ER60J476ME20
1
Murata
C
BYP
1 µF, 0603, X5R, 6.3 V
GRM188R60J105KA01
1
Murata
C
OUT
47 µF, 1210, X5R, 6.3 V
GRM32ER60J476ME20
1
Murata
L
2.5 µH, 10 m
Ω
MSS1038-252NL
1
Coilcraft
R
F
1
Ω
, 0603
CRCW06031R0J-e3
1
Vishay-Dale
C
F
100 nF, 0603, X7R, 16 V
GRM188R71C104KA01
1
Murata
C
EXT
1 µF, 0603, X5R, 6.3 V
GRM188R60J105KA01
1
Murata
R
PG
10 k
Ω
, 0603
CRCW06031002F-e3
1
Vishay-Dale
R
C1
1 k
Ω
, 0603
CRCW06031001F-e3
1
Vishay-Dale
C
C1
5.6 nF, 0603, X7R, 25 V
VJ0603Y562KXXA
1
Vishay-Vitramon
C
C2
OPEN
OPEN
0
N/A
C
SS
33 nF, 0603, X7R, 25 V
VJ0603Y333KXXA
1
Vishay-Vitramon
R
FB1
4.99 k
Ω
, 0603
CRCW06034991F-e3
1
Vishay-Dale
R
FB2
10 k
Ω
, 0603
CRCW06031002F-e3
1
Vishay-Dale
Test Points
Test Points
160-1026-02-01-00
8
Cambion
3
Connection Descriptions
Terminal Silkscreen
Description
V
IN
This terminal is the input voltage to the device. The device will operation over the input voltage
range of 2.95 V to 5.5 V. The absolute maximum voltage rating for this pin is 6 V.
GND
This terminal is the ground connection to the device. There are two different GND connections
on the PCB. One should be used for the input supply and the other for the load.
V
OUT
This terminal connects to the output voltage of the power supply and should be connected to
the load.
EN
This terminal connects to the enable pin of the device. This terminal should be connected to V
IN
or driven externally. If driven externally, a voltage typically greater than 1.18 V will enable the
device. The operating voltage for this pin should not exceed 5.5 V. The absolute maximum
voltage rating on this pin is 6 V.
SS/TRACK
This terminal provides access to the SS/TRK pin of the device. Connections to this terminal are
not needed for most applications. The feedback pin of the device will track the voltage on the
SS/TRK pin if it is driven with an external voltage source that is below the 0.8 V reference. The
voltage on this pin should not exceed 5.5 V during normal operation. The absolute maximum
voltage rating on this pin is 6 V.
PGOOD
This terminal connects to the power good output of the device. There is a 10 k
Ω
pull-up resistor
from this pin to the input voltage. The voltage on this pin should not exceed 5.5 V during
normal operation and has an absolute maximum voltage rating of 6 V.
SYNC
This terminal connects to the SYNC pin of the device. If this pin is left open the switching
frequency will default to approximately 400kHz. The voltage on this pin should not exceed 5.5
V during normal operation and has an absolute maximum voltage rating of 6 V.
2
AN-1688 LM20133 Evaluation Board
SNVA274B – October 2007 – Revised May 2013
Copyright © 2007–2013, Texas Instruments Incorporated