LXMG1930-28-0x 3-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 5mA steps through an on board DIP switch. The LXMG1930-28-0x 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 three output connectors. • Drives Up To 3 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 5mA Steps from 15mA to 50mA 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 • Output Over Voltage Protection • LED Over Temperature Protection Input WWW . Microsemi .C OM LXMG1930-28-0x module is a boost white LED driver for medium size LCD LED backlight panels. It is designed to drive up to three strings of LEDs to a maximum of 35V at up to 50mA per string. The module consists of a boost converter and three programmable 15 to 50 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 LXMG1930-28-01 Wide Input Voltage Range 4.75V to 28V CN4 Drives Up To Three String LED Panels. LED String Voltage up to 35V CN1 X SW4 4 Precision String-to-String Current Matching ON SW3 3 Externally Programmable LED String Current From 15mA to 50mA in 5mA Steps PWM Signal Supports Multi-Method Analog Dimming LXMG1930-28-0x Potentiometer SW2 2 DC Voltage Source SW1 1 DIMMING INPUT: Analog – Current Amplitude Dimming ORDER INFORMATION Part Number LXMG1930-28-01 LXMG1930-28-03 LXMG1930-28-04 Copyright © 2009 Rev. 1.1, 2009-11-25 Input Connector Output Connector Molex 53261-0871 or equivalent Molex 53261-0471 or equivalent Hirose DF19G-8P-1H or equivalent Kyocera 04-6298-006-000-883+ 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 LXMG1930-28-0x 3-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 ....................................................................................................................... 53mA (Internally Limited) Output String Voltage .......................................................................................................................... 38V (Internally Limited) Output Power ................................................................................................................................................................... 5.5W Input Signal Voltage (ENABLE Input).................................................................................................................... -0.3V to 30V 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 15 50 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-SW1~3 = ON; OT = open Parameter Symbol Test Conditions / Comment VIN Sleep Current IIN(MIN) ENABLE = 0V Supply Current IRUN5 VIN = 5V; VLED = 31.2V, ILED = 50mA; 3 Strings Supply Current IRUN12 VIN = 12V; VLED = 31.2V, ILED = 50mA; 3 Strings Supply Current During Fault Timeout IFAULT Open All Output Strings Fault Timeout Estimated Efficiency η VIN = 12V; VLED = 31.2V, ILED = 50mA; 3 Strings Typ Max Units 4.75 12 28 V 20 100 µA 1.5 A 0.5 0.6 A 6 10 mA 80 85 % Logic ENABLE Input Low Voltage ENABLE Input Hi Voltage ENABLE VL ENABLE VH DIP-SW1~3 = ON 2.0 0.8 V VIN V 2.2 V DIMMING BRITE_A voltage for Full Bright Copyright © 2009 Rev. 1.1, 2009-11-25 1.8 VBRITE_A 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 LXMG1930-28-0x Input Voltage Min LXMG1930-28-0x ® TM 3-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-SW1~3 = 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 = 50mA, 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 Switch1~3 ON/OFF 15 25 27 V 50 mA LED Current Sink Outputs LED DC Current Programming Range ICS LED DC Current ICSMIN VDIP-SW1~3 = OFF 14.25 15 15.75 mA LED DC Current ΔICSA Delta current SW1~3 = OFF to DIP-SW1= ON 4.75 5 5.25 mA LED DC Current ΔICSB Delta current SW1~3 = OFF to DIP-SW2= ON 9.5 10 10.5 mA LED DC Current ΔICSC Delta current SW1~3 = OFF to DIP-SW3= ON 19 20 21 mA LED DC Current ICSMAX VDIP-SW1~3 = ON 47.5 50 52.5 mA 2 % Current Matching Between Strings. VCSX = 0.8V to 5V -2 Regulated CS Pin Voltage At the lowest CS pin, ICSX = 50mA; DIP- SW1~3 = ON 0.5 Rated LED current VIN 0.9 V LED String Voltage LED String Voltage VLED 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 LXMG1930-28-0x LED Over Temperature Shut Down Threshold Over Temperature Recovery Voltage LXMG1930-28-0x ® TM 3-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET Name Pin # Description CN1 (Molex 53261-0871) for LXMG1930-28-0x 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 From This Pin To Ground. Analog Dimming Input. BRITE_A 0~2.2V→Io 10%~100%. 100Hz<f <25kHz, 3.3V PWM and 500kohms Rheostat are Equivalent Dimming Methods. No Connect, Leave This Pin Open WWW . Microsemi .C OM FUNCTIONAL PIN DESCRIPTION CN2 (Kyocera 04-6298-006-000-883+) for LXMG1930-28-04 (Please verify proper polarity of FPC to panel backlight connection) CN2-1 Anode CN2-2 CSA CN2-3 Anode CN2-4 CSB CN2-5 Anode CN2-6 CSC Common LED High Side Drive Voltage 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 CN3 (Hirose DF19G-8P-1H) for LXMG1930-28-03 CN3-1 Anode Common LED High Side Drive Voltage CN3-2 CSA CN3-3 Anode CN3-4 CSB CN3-5 Anode CN3-6 CSC CN3-7 NC No Connect CN3-8 NC No Connect 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 LXMG1930-28-0x CN4 (Molex 53261-0471) for LXMG1930-28-01 CN4-1 Anode CN4-2 CSA Channel A Cathode Sink Driver CN4-3 CSB Channel B Cathode Sink Driver CN4-4 CSC Channel C Cathode Sink Driver Copyright © 2009 Rev. 1.1, 2009-11-25 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 LXMG1930-28-0x ® TM 3-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET DIP SWITCH LED STRING CURRENT SETTINGS SW2 (10mA) SW3 (20mA) OFF OFF ON LED String Current Notes OFF 15mA Minimum String current OFF OFF 20mA OFF ON OFF 25mA ON ON OFF 30mA OFF OFF ON 35mA ON OFF ON 40mA OFF ON ON 45mA ON ON ON 50mA 1 2 Maximum String Current UP - ON ON DIP Switch S1 SW4 (not used) WWW . Microsemi .C OM SW1 (5mA) 3 4 DOWN - OFF Example shows S1 programmed for 25mA LED String Current LXMG1930-28-0x 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 LXMG1930-28-0x 3-String 5W LED Backlight Boost Driver Module ® TM P RODUCTION D ATASHEET SIMPLIFIED BLOCK DIAGRAM LED High Side Drive Voltage VIN ENABLE BRITE_A CSA 1 2 CSB 3 4 CSC 5 6 WWW . Microsemi .C OM +5V CN2 Control Circuitry +5V CSA 1 2 CSB 3 4 CSC 20.5k 5 6 7 8 OT CN3 GND ANODE CSA 1 2 CSB 3 4 CSC CN4 SW1 SW2 SW3 DIP Switch 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. CN4 CN2 CN1 27.9 mm 1.098 in. X 21.08 mm ±0.2 0.83 in. 2 SW3 3 SW4 4 3.22mm 0.127in S1 53.48mm ±0.2 2.11in. 69 mm CN3 MOUNTING HOLE 3.18MM ±.08 DIA. 1.0 mm 0.039 in. 2.72in. 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 LXMG1930-28-0x 1 SW2 ON SW1 LXMG1930-28-0x ® TM 3-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET APPLICATION INFORMATION 4.75V to 28V 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 2.2V divided by the logic high voltage level; with 3.3V logic level this corresponds to about 66% 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 Voltage Source, DAC, or Potentiometer ANODE CSA LXMG1930-28-0x 0V to 2.2V ANODE CSB BRITE_A 500k ANODE CSC ENABLE GND 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 LXMG1930-28-0x 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 LXMG1930-28-0x TM ® 3-String 5W LED Backlight Boost Driver Module P RODUCTION D ATASHEET NOTES WWW . Microsemi .C OM LXMG1930-28-0x 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