Microsemi LX23224IDB User manual

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 1
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
urce Control Drawing
LX23224IDB
Evaluation Board
User Guide
Revision 0.2
Reference Documents
LX23224IDB - 4 Channel EDGE-Lit LED Display Driver with DC/DC PSU Controllers,
Cat. No. DS_LX23224
AN 195 - Designing an EDGE-Lit LED BackLight System Based LX23224,
Cat. No. 06-0131-80

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 2
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
Table of Contents
1About this Guide...........................................................................................3
1.1 Audience.......................................................................................................................................3
1.2 Organization .................................................................................................................................3
1.3 Abbreviations................................................................................................................................3
2Introduction..................................................................................................4
2.1 EVB Features ...............................................................................................................................4
2.2 System Architecture .....................................................................................................................5
2.3 Interfaces and Connections..........................................................................................................5
3Physical Description ....................................................................................6
3.1 Connectors ...................................................................................................................................6
3.2 Test Points....................................................................................................................................7
3.3 DIP Switch SW1 ...........................................................................................................................7
4Installation ...................................................................................................8
4.1 Preliminary Steps and Safety Precautions...................................................................................8
4.2 LED Demo Panel Configuration ...................................................................................................8
4.3 Hardware Setup............................................................................................................................9
5Troubleshooting .........................................................................................10

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 3
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
1 About this Guide
This document provides a description and operation procedures for Microsemi's LX23224IDB Evaluation Board.
1.1 Audience
This document is intended for qualified personnel, meaning operators and technicians who have a background in
electronics and are familiar with its basic concepts.
1.2 Organization
This guide is divided into the following sections:
•
Chapter 1
About this Guide: Describes the objectives, audience, and organization of this guide.
•Chapter 2
Introduction: Describes the Evaluation Board main functions and features, and the
system architecture.
•Chapter 3
Physical Description: Provides explanation about the connectors, indicators, and
test points.
•
Chapter 4
Installation: Describes installation procedure for the System Board.
•
Chapter 5
Troubleshooting: Provides a guide for troubleshooting
1.3 Abbreviations
PWM: Pulse Width Modulation
VDC/DC: DC/DC output voltage
Vin: Input Voltage

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 4
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
2 Introduction
Microsemi’s Evaluation Kit (see Figure 1) provides designers with a platform to evaluate the performance and
implementation of LX23224IDB EDGE-Lit LED Display Driver.
All necessary steps and connection instructions required to install and operate this board are provided within this
document.
Backlight Demo System enables Back Light LCD designers to evaluate Microsemi's driver EDGE-Lit solution with
maximum flexibility and ease in configuration.
Figure 1: LX23224DB Evaluation Board – General View
2.1 EVB Features
LX23224IDB supports four LED strings
Digital dimming input
Minimum duty cycle 4%@2KHz
Per string voltage monitoring for failure events detection
Controls LED string voltage for power loses reduction
LED driver inherent thermal protection
System input voltage and output voltage monitoring
125 mA/string
120V output voltage
140KHz DC/DC switching frequency
RoHS compliant

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 5
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
2.2 System Architecture
Figure 2 depicts block diagram of LX23224IDB Evaluation Board.
LX23224IDB LED Driver controlls a DC/DC and four LED strings
J1
DC/DC #1 Block
String #3/4 external
components
String #1/2 external
components
J8 J7 J9 J6
J5
SW1
String 1
Connector
String 2
Connector
String 3
Connector
String 4
Connector
24 Vin
Connector
C.S.
148
LX23224IDB
Figure 2: System Architecture – Block Diagram
2.3 Interfaces and Connections
The board has several interfaces:
LEDs: A connection between LED strings and the LED driver output terminals. Connection is
made through dedicated connectors (J6, J7, J8, J9).
User: A user can turn system on/off by using a switch (SW1) and insert a digital PWM
information via connector J5 .
Power Supply: 24V input, fed by an external power supply (J1).

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 6
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
3 Physical Description
The following sections describe the board's connectors, test points and switches.
3.1 Connectors
Table 1 lists board's connectors.
Table 1: Evaluation Board's Connectors
Connector
Name
Description
J6, J7, J8, J9
LED strings
connectors
Connect LED strings to LED driver. Each connector has 6
pins, for LED string and for VDC/DC.
J1
Power
An 8 pin connector; for Vin and AGND.
J5
Host
2 pin connectors; for digital PWM input information
3.1.1 17BLED Strings Connectors J6, J7, J8, J9
Table 2 lists the two dedicated LED connectors that connect to Microsemi LED demo panel (PR-1004-A01).
Table 2: LED Strings Connectors Table – Pin Description
Connector Pin No. Signal Name Description
J6
1
VDC/DC
Output voltage to LED string anode
2
VDC/DC
Output voltage to LED string anode
3
VD1
LED string 1 cathode return path
4
N.C.
Not connected
5
N.C.
Not connected
6
N.C.
Not connected
J7
1
VDC/DC
Output voltage to LED string anode
2
VDC/DC
Output voltage to LED string anode
3
VD3
LED string 3 cathode return path
4
N.C.
Not connected
5
N.C.
Not connected
6
N.C.
Not connected
J8
1
VDC/DC
Output voltage to LED string anode
2
VDC/DC
Output voltage to LED string anode
3
VD4
LED string 4 cathode return path
4
N.C.
Not connected
5
N.C.
Not connected
6
N.C.
Not connected
J9
1
VDC/DC
Output voltage to LED string anode
2
VDC/DC
Output voltage to LED string anode
3
VD2
LED string 2 cathode return path
4
N.C.
Not connected
5
N.C.
Not connected
6
N.C.
Not connected
Manufacturer: CviLux
Manufacture part number: CH81-062V100

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 7
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
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3.1.2 Power Connector J1
This connection supplies operating voltage for the whole LED backlight platform. Connector is connected to both
high power supplies and LED driver.
Table 3: Power Connector Table – Pin Description
Pin No. Signal Name Description
1, 2, 3, 4
Vin
Application input voltage
5, 6, 7, 8
AGND
Ground connection for power return
Manufacturer: CviLux
Manufacture part number: CI5208P1H00
3.1.3 19BHost Connectors J5
Table 4: Host Connectors Table – Pin Description
Connector Pin No. Signal Name Description
J5
1
DIGITAL_DIM1
Digital dimming input line (5V tolerate)
2
AGND
Ground connection for signals return
Manufacturer: CviLux
Manufacture part number (J5): CH31-021V200
3.2 12BTest Points
Table 5 describes the on-board test points and their functions.
Table 5: On-Board Test Points
FunctionalityTPs NameTest Point
Analog ground
AGND
TP5,TP10,TP13
Power ground 1
PGND1
TP7,TP9,TP12
Power ground 2
PGND2
TP6,TP8,TP11
Power supplies synchronization signal
PS_SYNC
TP1
System on/off signal
EN_BLU
TP13
3.3 13BDIP Switch SW1
Evaluation board contains switch used for switching on or off the LED backlight system (Figure 3).
Figure 3: System On/Off Switch

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 8
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
4 Installation
The following chapter describes the steps required for installing and operating the Evaluation Board.
4.1 Preliminary Steps and Safety Precautions
Connect all required peripherals prior to powering the board. (LED’s, digital dimming generator)
Do not perform a hot-swap!
Verify board is properly configured prior to turning on power supply. (LED’s per srting. SW1 at BL
OFF state)
4.2 LED Demo Panel Configuration
WARNING!
Do not look directly at the LED panel when system is operating and LED panels are illuminating.
The following paragraph describes the steps required for LED panel configuration.
The panel contains 48 high-power white LEDs connected in series as one string and 10 configuration switches (see
Figure 4). Users can configure the LED string LED count to any LED number they need.
Single LED forward voltage is 3V@125mA, therefore for 120V output-voltage 40 LEDs are needed.
LED OFF
LED ON
510 20 143 3 2 ALL
W/O
WITH
CHAIN
SW1 SW2
Figure 4: LED Number Configuration Switches and PCB Silk
•W/O WITH switch – LED string chaining switch. For applications with output-voltage lower than 150V
this switch should be moved to W/O.
•5, 10, 20, 1, 4, 3, 3, 2 switches – LED number configuration switches.
For example:
VLED
Total LED
SW “5”
SW “10”
SW “20”
SW “1”
SW “4”
SW “3”
SW “3”
SW “2”
63V
21
OFF
OFF
ON
ON
OFF
OFF
OFF
OFF
63V
21
ON
ON
OFF
OFF
ON
OFF
OFF
ON
120V
40
ON
ON
ON
ON
ON
OFF
OFF
OFF
•ALL switch – LED string short circuit switch. To short circuit entire string, move switch to LED OFF. To
release the short, move switch to LED ON.
4.2.1 Fault simulation using the LED Demo Panel
During normal system operation users can perform various fault conditions using the LED Demo panel
switches.
•Open string – By moving “W/O WITH” switch to WITH
•Short entire string – By moving “ALL” switch to LED OFF
•LED short – Users should choose LED number to be shorted and move suitable switch to LED OFF.

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 9
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
4.3 Hardware Setup
1. Set power supply to 24V output. (Don’t turn ON the power supply yet)
Verify its minimum current capability; power supply must provide 4A.
2. Connect the power cable to J1 connector (Figure 55).
3. Plug power cable connectors to the power supply.
Red connector is pluged in the positive output terminal.
Black connector is pluged in the negative output terminal.
J1
Figure 5: Power Cable
4. Connect LED loads to LED Strings Connectors J6, J7, J8, and J9. (LED string forward voltage should be set in
the rage of 110V to 120V)
6. Turn on the 24V power supply.
7. Connect signal generator to connector J5.
8. Switch SW1 to BL_ON position.
9. Evaluate the system.

LX23224IDB Evaluation Board U Us se er r G Gu ui id de e
Copyright © 2011 Microsemi 10
Rev. 0.2, 10-04-2011 Analog Mixed Signal Group
2381 Morse Avenue, Irvine, CA 92614, USA; Within the USA: [phone], Outside the USA: [phone] Fax: [phone]
5 Troubleshooting
Table 6 provides a troubleshooting guide. Scenarios defined in the table are simple and do not take into account
human error or multiple failures. Corrective action is to be done in a sequential manner.
Table 6: LED System Board Troubleshooting Guide
Symptom Corrective Action
System Board does not power
up; no voltage on V12V (C23)
and VDD (C44) pins
1. Verify power is applied to the 24V cable.
2. Verify correct polarity is supplied to Board.
3. Check power cable at J1 is well connected.
LED strings do not illuminate.
1. Ensure a proper connection between EVB and LED panel.
2. Verify SW1 switch is set to BL_ON.
3. Verify dimming information is provided. (measured on J5 pin 1)
4. Verify fuse F1 is conducting.
5. Verify Fault pin (22) is high (5V). If it’s low try to check LED
strings connection.