LXMG1960-28-0x 6-String 5W LED Backlight Boost Driver Module ® TM P RODUCTION D ATASHEET • DESCRIPTION Precision current mirror circuitry typically provides for 1% percent string to string matching at the rated output current. The magnitude of the string current is easily programmed, in 1mA steps through an on board DIP switch. The LXMG1960-28-0x includes over voltage protection (OVP), and short and open LED protection. If one string opens, its current sink will be disabled and the other strings will continue to operate normally. Likewise if one or several LEDs in a string short it will continue to function with no adverse affect on the other strings. With the use of an external thermistor the module can provide LED current fold back in an over temperature situation. The module comes in a small form factor PCB and uses an 8 pin input and one of two output connectors. • Drives Up To 6 String LED Panels • Strings Can Be Combined For Higher Current • Wide Input Voltage 4.75V-28V • String Voltage Up To 35V • LED String Current Programmable in 1mA Steps from 10 to 25mA For Matching Various Panel Requirements • 1% Typical String-to-String Current Matching • Analog Dimming Provides For a 10:1 Ratio • Supports Multiple Methods Of Dimming Such As DC Voltage, PWM Signal and Potentiometer • Over Voltage Protection • LED Over Temperature Protection Input WWW . Microsemi .C OM LXMG1960-28-0x module is a boost white LED driver for medium size LCD LED backlight panels. It is designed to drive up to six strings of LEDs to a maximum of 35V at up to 25mA per string. The module consists of a boost converter and six programmable 10-25 mA precision current sinks. It is designed to work over a wide input voltage range (4.75V to 28V) providing maximum flexibility. However the converter is a boost only design requiring the input supply voltage to not exceed the output LED string voltage. The module provides a dimming input: BRITE_A which adjusts the LED display brightness by controlling the amplitude of the LED string current. The BRITE_A input is very flexible and can be controlled by a PWM signal, the application of a DC control voltage or use of a potentiometer tied as a rheostat. KEY FEATURES APPLICATIONS • Medium Size White LED Backlight LCD Displays • Portable Instrumentation Displays • Medical Instrument Displays IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com Patents Pending PRODUCT HIGHLIGHT LXMG1960-28-01 Wide Input Voltage Range 4.75V to 28V Drives Six String LED Panels. LED String Voltage up to 35V CN1 X ON SW3 3 SW4 4 CN2 Precision String-to-String Current Matching Externally Programmable LED String Current From 10mA to 25mA in 1mA Steps PWM Signal Supports Multi-Method Analog Dimming LXMG1960-28-0x Potentiometer SW2 2 DC Voltage Source SW1 1 DIMMING INPUT: Analog – Current Amplitude Dimming ORDER INFORMATION Part Number Input Connector LXMG1960-28-01 LXMG1960-28-03 Molex 53261-0871 or equivalent Copyright © 2009 Rev. 1.1, 2009-11-25 Output Connector Molex 53261-0771 or equivalent Hirose DF14A-15P-1.25H or equivalent Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 1 LXMG1960-28-0x 6-String 5W LED Backlight Boost Driver Module ® TM P RODUCTION D ATASHEET ABSOLUTE MAXIMUM RATINGS Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of specified terminal. WWW . Microsemi .C OM Input Voltage (VIN)................................................................................................................................................. -0.3V to 30V Input Power ...................................................................................................................................................................... 6.2W Output String Current ....................................................................................................................... 27mA (Internally Limited) Output String Voltage .......................................................................................................................... 36V (Internally Limited) Output Power ................................................................................................................................................................... 5.5W CSx Pins ............................................................................................................................................................... -0.3V to 28V Input Signal Voltage (ENABLE Input)..................................................................................................................... -0.3V to VIN Input Signal Voltage (OT)........................................................................................................................................ -0.3V to 5V Input Signal Voltage (BRITE_A).............................................................................................................................. -0.3V to 6V Ambient Operating Temperature, zero airflow ....................................................................................................-30°C to 80°C Storage Temperature Range ..............................................................................................................................-40°C to 85°C RECOMMENDED OPERATING CONDITIONS (R.C.) This module has been designed to operate over a wide range of input and output conditions. However, best efficiency and performance will be obtained if the module is operated under the condition listed in the ‘R.C.’ column. Min. and Max. columns indicate values beyond which the inverter, although operational, might not function optimally. Parameter Input Supply Voltage Range Linear BRITE_A Control Input Voltage Range LED String Voltage Each Cathode Sink Current Operating Ambient Temperature Range Symbol Min R.C. Max Units VIN 4.75 12 28 V VBRITE_A 0.2 2.2 V VLED VIN 35* V CSISINK 10 25 mA TA -30 75 °C * Input supply voltage should not exceed LED string voltage as this will result in excessive power dissipation in the module. ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the recommended operating condition and ambient temperature of 0°C to 60°C except where otherwise noted; VIN = 4.75V; BRITE_A = Open; ENABLE = VIN; DIP-SW1~4 = ON; OT = open Parameter Symbol Input Voltage Test Conditions / Comment VIN Min Typ Max Units 4.75 12 28 V 13 100 µA IIN(MIN) ENABLE = 0V Supply Current IRUN_5 VIN = 5V; VLED = 31.2V, ILED = 25mA; 6 Strings 1.25 1.5 A Supply Current IRUN_12 VIN = 12V;V LED = 31.2V, ILED = 25mA; 6 Strings 0.5 0.6 A Supply Current After Fault Timeout IFAULT Open all output strings Fault Timeout 6 10 mA η VIN = 12V; VLED = 31.2V, ILED = 25mA; 6 Strings Estimated Efficiency 80 85 % Logic ENABLE Input Low Voltage ENABLE Input Hi Voltage ENABLE VL 0 0.8 V ENABLE VH 2.0 VIN V VBRITE_A 1.8 2.2 V Dimming BRITE_A voltage for Full Bright Copyright © 2009 Rev. 1.1, 2009-11-25 2.0 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 2 LXMG1960-28-0x Off Current LXMG1960-28-0x ® TM 6-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET ELECTRICAL CHARACTERISTICS Unless otherwise specified, the following specifications apply over the recommended operating condition and ambient temperature of 0°C to 60°C except where otherwise noted; VIN = 4.75V; BRITE_A = Open; ENABLE = VIN; DIP-SW1~4 = ON; OT = open Symbol Min Typ Max Units POT 400 500 600 kΩ fBRITE_A 100 25000 Hz BRITE_A PWM Voltage VBRITE_A-PWM 2.5 5.5 V BRITE_A Sink Current IBRITE_A Potentiometer Dimming on BRITE_A PWM Frequency Range for BRITE_A Output Current Dim Range (Analog Dimming) Test Conditions / Comment BRITE_A = 0V 12 µA ILED = 25mA, BRITE_A = 0V Versus BRITE_A ≥ 2.2V 10 RATIO LED Current On Rise Time TCS_Rise 200 ns LED Current Off Fall Time TCS_Fall 400 ns 15 V WWW . Microsemi .C OM Parameter Device Protection LED Short Protection Threshold VcsSD Voltage at CSx pin that latches off its respective string. CS Pin Over-voltage Limit VCSOV Voltage at CSx pin that clamps Anode Output 23 Combination of DIP switch1~4 ON/OFF 10 25 27 V 25 mA LED Current Sink Outputs Nominal LED DC Current Programming Range ICS LED DC Current ICSMIN VDIP-SW1~4 = OFF 9.5 10 10.5 mA LED DC Current ΔICS1 Delta current SW1~4 = OFF to DIP-SW1= ON 0.95 1 1.05 mA LED DC Current ΔICS2 Delta current SW1~4 = OFF to DIP-SW2= ON 1.9 2 2.1 mA LED DC Current ΔICS3 Delta current SW1~4 = OFF to DIP-SW3= ON 3.8 4 4.2 mA LED DC Current ΔICS4 Delta current SW1~4 = OFF to DIP-SW4= ON 7.6 8 8.4 mA LED DC Current ICSMAX VDIP-SW1~4 = ON 23.75 25 26.25 mA 2 % Current Matching between strings. VCSX = 0.8V to 5V At the lowest CS pin, ICSX = 25mA; Regulated CS Pin Voltage -2 0.5 0.9 V LED String Voltage LED String Voltage VLED Rated LED current VIN 35 V LED Panel Thermal Protection VOT OT Sink Current IOT Copyright © 2009 Rev. 1.1, 2009-11-25 VOT OT = 0V 1.47 V 1.8 V 240 µA Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 3 LXMG1960-28-0x LED Over Temperature Shut Down Threshold Over Temperature Recovery Voltage LXMG1960-28-0x ® TM 6-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET FUNCTIONAL PIN DESCRIPTION Name Pin # Description CN1-1 CN1-2 CN1-3 CN1-4 VIN GND CN1-5 ENABLE CN1-6 OT CN1-7 BRITE_A CN1-8 NC Main Input Power Supply 4.75V to 28V Power Supply Return ON/OFF Control. (ENABLE = 0V = OFF, ENABLE = 2V = ON) Operating Temperature Detection Input. A Thermistor Usually Is Connected This Pin To The Ground. Analog Dimming Input. BRITE_A 0~2.5V→Io 10%~100%. 100Hz<f <25kHz, 3.3V PWM and 500kohms Rheostat are Equivalent Dimming Methods. Open = Maximum Programmed String Current No Connect, Leave This Pin Open WWW . Microsemi .C OM CN1 (Molex 53261-0871) for LXMG1960-28-01/03 CN2 (Molex 53261-0771) for LXMG1960-28-01 CN2-1 Anode Common LED High Side Drive Voltage CN2-2 CSA Channel A Cathode Sink Driver CN2-3 CSB Channel B Cathode Sink Driver CN2-4 CSC Channel C Cathode Sink Driver CN2-5 CSD Channel D Cathode Sink Driver CN2-6 CSE Channel E Cathode Sink Driver CN2-7 CSF Channel F Cathode Sink Driver CN3 (Hirose DF14A-15P-1.25H) for LXMG1960-28-03 CN3-1 Anode CN3-2 CSA CN3-3 Anode CN3-4 CSB CN3-5 Anode CN3-6 CSC CN3-7 Anode CN3-8 CSD CN3-9 Anode CN3-10 CSE CN3-11 Anode CN3-12 CSF Channel F Cathode Sink Driver CN3-13 N/A No Connection Pin Is Open CN3-14 N/A No Connection Pin Is Open CN3-15 N/A No Connection Pin Is Open Channel A Cathode Sink Driver Common LED High Side Drive Voltage Channel B Cathode Sink Driver Common LED High Side Drive Voltage Channel C Cathode Sink Driver Common LED High Side Drive Voltage Channel D Cathode Sink Driver Common LED High Side Drive Voltage LXMG1960-28-0x Copyright © 2009 Rev. 1.1, 2009-11-25 Common LED High Side Drive Voltage Channel E Cathode Sink Driver Common LED High Side Drive Voltage Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 4 LXMG1960-28-0x 6-String 5W LED Backlight Boost Driver Module ® TM P RODUCTION D ATASHEET DIP SWITCH LED STRING CURRENT SETTINGS SW2 (2mA) SW3 (4mA) SW4 (8mA) LED String Current Notes OFF OFF OFF OFF 10mA Minimum String current ON OFF OFF OFF 11mA OFF ON OFF OFF 12mA ON ON OFF OFF 13mA OFF OFF ON OFF 14mA ON OFF ON OFF 15mA OFF ON ON OFF 16mA ON ON ON OFF 17mA OFF OFF OFF ON 18mA ON OFF OFF ON 19mA OFF ON OFF ON 20mA ON ON OFF ON 21mA OFF OFF ON ON 22mA ON OFF ON ON 23mA OFF ON ON ON 24mA ON ON ON ON 25mA 1 2 Maximum String Current UP - ON ON DIP Switch S1 WWW . Microsemi .C OM SW1 (1mA) 3 4 DOWN - OFF Example shows S1 programmed for 20mA LED String Current LXMG1960-28-0x Copyright © 2009 Rev. 1.1, 2009-11-25 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 5 LXMG1960-28-0x 6-String 5W LED Backlight Boost Driver Module ® TM P RODUCTION D ATASHEET SIMPLIFIED BLOCK DIAGRAM LED High Side Drive Voltage VIN ENABLE BRITE_A Control Circuitry CSA 1 2 CSB 3 4 CSC 5 6 CSD 7 8 WWW . Microsemi .C OM +5V 9 CSE 10 11 CSF 12 +5V 13 14 20.5k 15 OT CN3 GND ANODE CSA 1 2 CSB 3 4 CSC CSD DIP Switch CSE SW1 SW2 SW3 SW4 CSF 5 6 7 CN2 MECHANICAL DRAWING 3.6mm 0.142in. GROUNDED MOUNTING HOLE 3.18MM ±.08 DIA. 49.88mm ±0.2 6.0 mm MAX 0.236 in. 1.96in. 27.9 mm 1.098 in. CN1 X 21.08 mm ±0.2 0.83 in. 2 SW3 3 SW4 4 3.22mm CN2 0.127in CN3 MOUNTING HOLE 3.18MM ±.08 DIA. 2.72in. 1.0 mm 0.039 in. Dimensions are in millimeters (inches are for reference only) PCB tolerances ± 0.5mm , M3 recommended mounting screws Weight: (8g) typ. Copyright © 2009 Rev. 1.1, 2009-11-25 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 6 LXMG1960-28-0x SW2 ON 1 69 mm SW1 LXMG1960-28-0x ® TM 6-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET APPLICATION INFORMATION 4.75V to 28V 0V to 2.5V 500k ANODE CSA ANODE CSB LXMG1960-28-0x ANODE CSC BRITE_A ANODE CSD ANODE CSE ANODE ENABLE GND CSF The LED string current and therefore the brightness may be controlled by the BRITE_A input. The typical dimming range using the BRITE_A input alone is 10:1. The BRITE_A input may come from a voltage output DAC or other voltage source, a 500k digital or manual pot, or a PWM signal in the range of 100 Hz to 25 kHz. The module contains an internal 422k pull-up to typically 5V to provide bias if using a pot. Logic levels may be used up to 5V, however the inverter will reach maximum current at less than 100% duty cycle. This can be calculated as approximately 2.3V divided by the logic high voltage level; with 3.3V logic level this corresponds to about 70% duty cycle for maximum string current. If you need to turn the module ON/OFF remotely, connect to TTL logic signal to the ENABLE input. It is to be noted that although the module provides for a wide input voltage range 4.75V to 28V it is designed as a boost only converter. Therefore the input voltage should not exceed the LED string voltage. Use of an external thermistor connected from OT pin to ground will provide over temperature protection (see figure 2). The module can provide for the gradual scaling back of LED string current until it is completely shut off based on the voltage level impressed on the OT input. When the voltage on the OT pin decreases below 2.48V the string current will begin to decrease until it is completely shut off when OT reaches 1.47V. This corresponds to a thermistor value of about 8542 ohms at string current shutdown. As an example using a 100k (at 25°C) NTC thermistor with a B Constant of 4250 will provide a thermal profile where the module will begin to scale back the LED string currents at a temperature (as measured by the thermistor) greater than 60°C and shut down the string current if the temperature exceeds 85°C. Although the module provides open circuit string protection, if the common LED high side drive voltage (Anode) is directly shorted to ground this will result in damage to the fuse and possible damage to the Schottky diode. Likewise if any of the low side current sink drivers (CSx) are directly shorted to ground it will result in damage to the fuse, Schottky diode and possibly the LED string. VIN Figure 1 +5V 20.5k OT (pin 6) VRT RT NTC 5 VRT = 20.5k + R x RT T Figure 2 WWW . Microsemi .C OM Voltage Source, DAC, or Potentiometer LXMG1960-28-0x Copyright © 2009 Rev. 1.1, 2009-11-25 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 7 LXMG1960-28-0x TM ® 6-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET NOTES WWW . Microsemi .C OM LXMG1960-28-0x PRODUCTION DATA – Information contained in this document is proprietary to Microsemi and is current as of publication date. This document may not be modified in any way without the express written consent of Microsemi. Product processing does not necessarily include testing of all parameters. Microsemi reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright © 2009 Rev. 1.1, 2009-11-25 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 800-877-6458, 714-898-8121, Fax: 714-893-2570 Page 8