User's Guide
SNVA119C – September 2005 – Revised April 2013
AN-1391 LM3204 Evaluation Board
1
Introduction
The LM3204 evaluation board is a working demonstration of a buck converter. This document contains
information about the board. For further information on buck converter topology and component selection,
see the device-specific data sheet.
2
General Description
The LM3204 converts high input voltages to lower output voltages with high efficiency. It does this through
a inductor based switching topology, applying the input voltage to the inductor for a certain portion of the
cycle. The duty cycle in pulse width modulation (PWM) mode will be VOUT / VIN, which can be seen on the
SW pin.
There are three modes of operation. These are fixed frequency PWM, forced bypass, and shutdown
mode. Setting the BYP pin low (1.2 V) places the device in forced bypass mode. Setting the EN pin low (1.2 V) enables normal operation.
At the PWM mode, the output voltage is setting by the voltage of the VCON pin, as in Equation 1:
VOUT = 3 x VCON
3
(1)
Operating Conditions
The board will operate under the following conditions:
2.7 V ≤ VIN ≤ 5.5 V
0.267 V ≤ VCON ≤ 1.2 V
0mA ≤ IOUT ≤ 300mA (PWM mode)
0mA ≤ IOUT ≤ 500mA (Bypass mode)
4
Schematic
VIN
C4
0.1 PF
C1
PVIN
10 PF
VDD
BYPOUT
EN
L1
2.2 PH
VOUT
SW
BYP
LM3204
FB
VCON
VCON
PGND
SGND
C2
4.7 PF
0.267V to 1.20V
Figure 1. Typical Operating Circuit
All trademarks are the property of their respective owners.
SNVA119C – September 2005 – Revised April 2013
Submit Documentation Feedback
Copyright © 2005–2013, Texas Instruments Incorporated
AN-1391 LM3204 Evaluation Board
1
Board Layout
5
www.ti.com
Board Layout
2.2uH
4.7uF
10uF
LM3204
0.1uF
Vcon
BYP
EN
Figure 2. Top Layer
xxxxxxxxx-001 rev A
LM3204
R7
R6
C3 R1
C5
R3
R2
Figure 3. Bottom Layer
2
AN-1391 LM3204 Evaluation Board
SNVA119C – September 2005 – Revised April 2013
Submit Documentation Feedback
Copyright © 2005–2013, Texas Instruments Incorporated
Board Schematic
www.ti.com
6
Board Schematic
R4
R6
0:
VIN
VDD
C4
0.1 PF
BYPOUT
PVIN
C1
10 PF
EN
E
R5
L1
2.2 PH
LM3204
B
BYP
SW
VCON
FB
VOUT
R3
C
R1
0:
R2
C2
4.7 PF
C3
C5
SGND
R7
0:
PGND
GND
Figure 4. Complete Evaluation Board Schematic
7
PCB Guidelines
For your application circuit, proper layout for the buck regulator should be implemented by following a few
simple guidelines. (Also, see the Board Layout Considerations section in the device-specific data sheet.)
• Place C1 right next to the device between PVIN and PGND pin.
• Place C4 right next to the device between VDD and SGND pin.
• Make the traces drawn with heavy lines, which are Power lines, as short and as wide as possible.
• Making the traces drawn with heavy lines on the same layer should be good. However, place as many
vias as possible if traces are on multiple layers.
SNVA119C – September 2005 – Revised April 2013
Submit Documentation Feedback
Copyright © 2005–2013, Texas Instruments Incorporated
AN-1391 LM3204 Evaluation Board
3
Bill of Materials (BOM)
8
www.ti.com
Bill of Materials (BOM)
Table 1. Bill of Materials
Designator
Footprint
Manufacture
Manufacture #
Description
C1 (input C)
1206 (3216)
TDK
C3216JB1A106K
10 µF, 10 V, 20%
C2 (output C)
1206 (3216)
TDK
C2012JB0J475K
4.7 µF, 6.3 V, 20%
C3
0603 (1608)
optional
C4 (input C)
0402 (1005)
0.1 µF, 10 V, 20%
C5
0805 (2012)
optional
L1 (inductor)
Coilcraft
DO3314-222
2.2 µH inductor, 1.6A Isat, 0.2 Ωmax.
R1
0603 (1608)
0Ω
R2
0603 (1608)
optional
R3
0603 (1608)
optional
R4
Do not use
R5
0603 (1608)
optional
R6
0603 (1608)
0Ω
R7
0603 (1608)
0Ω
COMMON TO ALL
VIN banana jack - red
Johnson Components
108-0902-001
conn jack banana insul nylon red
VOUT banana jack - yellow
Johnson Components
108-0907-001
conn jack banana insul nylon yellow
GND banana jack - black
Johnson Components
108-0903-001
conn jack banana insul nylon black
9
Connection Diagrams
SGND
A2
SGND
A2
A3 BYPOUT
VDD A1
VCON B1
FB C1
B3 PVIN
PVIN B3
C3 SW
SW C3
D3 PGND
BYP D1
A1 VDD
BYPOUT A3
B1 VCON
C1 FB
D1 BYP
PGND D3
D2
EN
D2
EN
Figure 5. Top View
Figure 6. Bottom View
Figure 7. 10–Bump Thin DSBGA Package, Large Bump
4
AN-1391 LM3204 Evaluation Board
SNVA119C – September 2005 – Revised April 2013
Submit Documentation Feedback
Copyright © 2005–2013, Texas Instruments Incorporated
Connection Diagrams
www.ti.com
Table 2. Pin Descriptions
Pin No
Name
Description
A1
VDD
Analog Supply Input. A 0.1µF ceramic capacitor is recommended to be placed as close to this pin as
possible.
B1
VCON
Voltage Control Analog input. VCON controls VOUT in PWM mode.
Set: VOUT = 3 x VCON. Do not leave floating.
C1
FB
D1
BYP
Bypass. Use this digital input to command operation in Bypass mode. Set the BYP pin high (> 1.2 V )
for Bypass mode. Set BYP low (< 0.4 V ) for normal operation.
D2
EN
Enable Input. Set this digital input high (> 1.2 V) after VIN > 2.7 V for normal operation. For shutdown,
set low (< 0.4 V).
D3
PGND
C3
SW
Switching Node connection to the internal PFET switch and NFET synchronous rectifier. Connect to an
inductor with a saturation current rating that exceeds the maximum Switch Peak Current Limit
specification of the LM3204.
B3
PVIN
Power Supply Voltage Input to the internal PFET switch and Bypass FET.
A3
BYPOUT
Bypass FET Drain. Connect to the output capacitor. Do not leave floating.
A2
SGND
Feedback Analog Input. Connect to the output at the output filter capacitor.
Power Ground
Analog and Control Ground
SNVA119C – September 2005 – Revised April 2013
Submit Documentation Feedback
Copyright © 2005–2013, Texas Instruments Incorporated
AN-1391 LM3204 Evaluation Board
5
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other
changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest
issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and
complete. All semiconductor products (also referred to herein as “components”) are sold subject to TI’s terms and conditions of sale
supplied at the time of order acknowledgment.
TI warrants performance of its components to the specifications applicable at the time of sale, in accordance with the warranty in TI’s terms
and conditions of sale of semiconductor products. Testing and other quality control techniques are used to the extent TI deems necessary
to support this warranty. Except where mandated by applicable law, testing of all parameters of each component is not necessarily
performed.
TI assumes no liability for applications assistance or the design of Buyers’ products. Buyers are responsible for their products and
applications using TI components. To minimize the risks associated with Buyers’ products and applications, Buyers should provide
adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any patent right, copyright, mask work right, or
other intellectual property right relating to any combination, machine, or process in which TI components or services are used. Information
published by TI regarding third-party products or services does not constitute a license to use such products or services or a warranty or
endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the
third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of significant portions of TI information in TI data books or data sheets is permissible only if reproduction is without alteration
and is accompanied by all associated warranties, conditions, limitations, and notices. TI is not responsible or liable for such altered
documentation. Information of third parties may be subject to additional restrictions.
Resale of TI components or services with statements different from or beyond the parameters stated by TI for that component or service
voids all express and any implied warranties for the associated TI component or service and is an unfair and deceptive business practice.
TI is not responsible or liable for any such statements.
Buyer acknowledges and agrees that it is solely responsible for compliance with all legal, regulatory and safety-related requirements
concerning its products, and any use of TI components in its applications, notwithstanding any applications-related information or support
that may be provided by TI. Buyer represents and agrees that it has all the necessary expertise to create and implement safeguards which
anticipate dangerous consequences of failures, monitor failures and their consequences, lessen the likelihood of failures that might cause
harm and take appropriate remedial actions. Buyer will fully indemnify TI and its representatives against any damages arising out of the use
of any TI components in safety-critical applications.
In some cases, TI components may be promoted specifically to facilitate safety-related applications. With such components, TI’s goal is to
help enable customers to design and create their own end-product solutions that meet applicable functional safety standards and
requirements. Nonetheless, such components are subject to these terms.
No TI components are authorized for use in FDA Class III (or similar life-critical medical equipment) unless authorized officers of the parties
have executed a special agreement specifically governing such use.
Only those TI components which TI has specifically designated as military grade or “enhanced plastic” are designed and intended for use in
military/aerospace applications or environments. Buyer acknowledges and agrees that any military or aerospace use of TI components
which have not been so designated is solely at the Buyer's risk, and that Buyer is solely responsible for compliance with all legal and
regulatory requirements in connection with such use.
TI has specifically designated certain components as meeting ISO/TS16949 requirements, mainly for automotive use. In any case of use of
non-designated products, TI will not be responsible for any failure to meet ISO/TS16949.
Products
Applications
Audio
www.ti.com/audio
Automotive and Transportation
www.ti.com/automotive
Amplifiers
amplifier.ti.com
Communications and Telecom
www.ti.com/communications
Data Converters
dataconverter.ti.com
Computers and Peripherals
www.ti.com/computers
DLP® Products
www.dlp.com
Consumer Electronics
www.ti.com/consumer-apps
DSP
dsp.ti.com
Energy and Lighting
www.ti.com/energy
Clocks and Timers
www.ti.com/clocks
Industrial
www.ti.com/industrial
Interface
interface.ti.com
Medical
www.ti.com/medical
Logic
logic.ti.com
Security
www.ti.com/security
Power Mgmt
power.ti.com
Space, Avionics and Defense
www.ti.com/space-avionics-defense
Microcontrollers
microcontroller.ti.com
Video and Imaging
www.ti.com/video
RFID
www.ti-rfid.com
OMAP Applications Processors
www.ti.com/omap
TI E2E Community
e2e.ti.com
Wireless Connectivity
www.ti.com/wirelessconnectivity
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2013, Texas Instruments Incorporated