A M I C R O S E M I LX1686 Digital Dimming CCFL Controller IC C O M P A N Y P RODUCTION D ATA SHEET Safety and reliability features include a new dual feedback control loop that permits regulation of maximum lamp strike voltage as well as lamp current. Regulating maximum lamp voltage permits the designer to provide for ample worst case lamp strike voltage while at the same time conservatively limit maximum open circuit voltage. An innovative new strike voltage generation technique enables the nodule designer to optimize high voltage transformer design for maximum operating efficiency with no power dissipating overhead to guarantee strike capability Direct drive topology is a nonresonant, oscillator-controlled PWM regulation method. The LX1686 allows a wide choice of fixed operating frequencies to match lamp current frequency to the lamp’s most efficient operating point, and to minimize high frequency interference. RangeMAX™ Wide Range Dimming (>100:1) Synchronizable to Display Video Frequency High Voltage Feedback Loop Directly Controls Maximum Open Lamp Micro-Amp Sleep Mode User Programmable Fixed Frequency Operation Under-Voltage Lockout Feature With Power-Up Reset Built-In Soft-Start Feature Operates With 3.3V or 5V power Supplies 100mA Output Drive Capability W W W . Microsemi . COM The LX1686 Backlight Controller IC provides all the control functions needed to implement Linfinity’s direct drive inverters used to operate cold cathode fluorescent lamps (CCFL’s). This IC can be used to control single or multiple-lamp configurations. CCFL’s are used for back or edge lighting of liquid crystal flat panel displays (LCD’s) and typically find application in notebook computers, web browsers, automotive and industrial instrumentation, and entertainment systems. The LX1686 includes a PWM controlled lamp current burst circuit that can provide a > 100:1 dimming range from a simple zero to 2.5V potentiometer input. The PWM dimming burst rate is easily synchronized to the LCD panel’s frame rate to prevent interference from optical beat frequencies. Notebooks Instrumentation Display Desktop Computer Monitors Low Ambient Light Displays (used in Aircraft, Automobiles, and Hand-Held Equipment) IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com Extremely High Efficiency From 3.3V to 5V Power Supplies Lower Cost Than Conventional 5 Buck / Royer Inverter Topologies 4 Power Used (Watts) Improved Lamp Strike Capability Improved Over-Voltage Control Standard Analog Dimming Inverter 3 LinFinity's RangeMAX 2 Light emitted by a CCFL is proportional to the current flowing through it. There are two ways to control the current: by adjusting the amplitude of a continuous AC current; or, as with RangeMAX technology, by varying the amount of time a burst of full current is present. RangeMAX technology frees the backlight inverter module designer to operate in a lower brightness and lower power consumption mode than is possible with conventional amplitude control methods. 1 0 30 45 60 75 90 105 LX1686 0 Light Output (Nits) TJ (°C) PW 0 to 85 -40 to 85 Plastic TSSOP 24-PIN LX1686CPW LX1686IPW Note: Available in Tape & Reel. Append the letter “T” to the part number. (i.e. LX1686CPWT) Copyright 2000 Rev. 1.0, 2001-03-20 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 1 A M I C R O S E M I LX1686 Digital Dimming CCFL Controller IC C O M P A N Y P RODUCTION D ATA SHEET Supply Voltage (VDD, VDD_P)...................................................................................6.5V Digital Inputs........................................................................................ -0.3 to VDD +0.5V Analog Inputs ....................................................................................... -0.3 to VDD +0.5V Digital Outputs ..................................................................................... -0.3 to VDD +0.5V Analog Outputs..................................................................................... -0.3 to VDD +0.5V Operating Junction Temperature .............................................................................. 150°C Storage Temperature....................................................................................-65°C to 150°C Lead Temperature (Soldering, 10 Seconds)............................................................... 300°C A OUT 1 24 B OUT V S S _P 2 23 VSS 3 22 V D D _P VDD A F D _C 4 21 T R I_C R A M P _C 5 20 O LS N S R A M P _R 6 19 IS N S FVERT 7 18 IC O M P P D _C R 8 17 VSNS V C O _C 9 16 VCOMP B R T _P O S 10 15 BRT B R IT E 11 14 I_R D IG _D IM 12 13 E N A B LE 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 PW PACKAGE (Top View) W W W . Microsemi . COM PW PACKAGE THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 100°C/W Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. PACKAGE DATA Copyright 2000 Rev. 1.0, 2001-03-20 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 2 A M I C R O S E M I LX1686 Digital Dimming CCFL Controller IC C O M P A N Y P RODUCTION D ATA SHEET AOUT Output driver A. VSS_P Power ground for output drivers only. VSS AFD_C Signal ground. Connects to an external capacitor, CAFD. Forcing to ground or VDD will make the VCO oscillate at approximately 50% of the maximum VCO frequency. Forcing to VDD/2 will make the VCO oscillate at 2x the FVERT frequency. RAMP_C Connects to external capacitor CRAMP for setting Direct Drive PWM operating frequency. RAMP_R Connects to external resistor RRAMP for setting Direct Drive PWM operating frequency. FVERT Vertical frequency reference digital input. Has internal pull down. PD_CR Phase Detector Filter. Part of phase lock loop. Connects to external capacitor and resistor network. VCO_C Connects to external capacitor CVCO BRT_POS BRITE Brightness control polarity. Has internal pull up. Leave open or pull up to VDD for dimming brightness proportional to BRITE voltage, connect to ground for brightness inversely proportional to BRITE voltage. Analog voltage input for brightness control. DIG_DIM Digital Dimming Enable internal pull up. Leave open or pull up to VDD for operating in digital dimming mode. Connect to ground for analog dimming mode. ENABLE Chip Enable internal pull up. High enables the chip. Low disables. I_R Current Reference Resistor. External resistor to ground (Ri) determines internal capacitor CICOMP. BRT Current Error Amplifier non-inverting input VCOMP Voltage Error Amplifier output. Connects to external frequency compensation capacitor C VCOMP. Controls softstart timing. VSNS Voltage Error Amplifier inverting input. ICOMP Current Error Amplifier output. Connects to external frequency compensation capacitor CICOMP. ISNS Current Error Amplifier inverting Input. Open Lamp Sense Input. TRI_C Connects to external capacitor CTRI for setting strike Frequency ramp slope. VDD VDD_P Dedicated VDD for output buffers only. BOUT Output Driver B. Copyright 2000 Rev. 1.0, 2001-03-20 PACKAGE DATA OLSNS VDD W W W . Microsemi . COM Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 3 A M I C R O S E M I LX1686 Digital Dimming CCFL Controller IC C O M P A N Y P RODUCTION D ATA SHEET Unless otherwise specified, the following specifications apply over the operating ambient temperature -0°C ≤ TA ≤ 85°C for the LX1686CPW and -40°C ≤ TA ≤ 85°C for the LX1686IPW except where otherwise noted. Test conditions: VDD = VDD_P = 3.0 to 5.5V, Ri = 40kΩ, CVCO = 0.01µF, CAFD = 0.22µF, CTRI = 0.83µF, CRAMP = 208pF, RRAMP = 15kΩ, CPD = 0.22µF, CPDB = 0.047µF, RPD = 110kΩ Parameter Power Supply Voltage Operating Current Power Supply Voltage Output Buffer Operating Current UVLO Threshold UVLO Hysteresis Test Conditions VDD IDD VDD_P IDD_P VTH_UVLO VH_UVLO VDD = VDD_P VDD = VDD_P = 5V VDD = VDD_P Volsns = VDD = VDD_P = 5V, CA = CB = 1000pF Min LX1686 Typ 3 Max 160 V mA V mA V mV 2.25 V 0.75 V 10 Hz 5 3 2 2.7 5.5 7 5.5 10 2.9 Units DIRECT DRIVE RAMP BLOCK Triangular Wave Generator Analog VP_TRI Output Peak Voltage Triangular Wave Generator Analog VV_TRI Output Valley Voltage Triangular Wave Generator Oscillation F_TRI Frequency Triangular Wave Generator Oscillation ICHG_TRI Charge Current Triangular Wave Generator Oscillation IDISCHG_TRI Discharge Current Ramp Generator Analog Output Peak VP_RAMP Voltage Ramp Generator Analog Output Valley VV_RAMP Voltage Tri_c = 0V -2.3 -2.55 -2.9 µA Tri_c = 3V 2.3 2.65 2.9 µA Ramp Frequency Change Threshold VTH_RAMP_R VDD = 3V VDD = 5.5V 1.35 1.55 1.5 1.65 1.65 1.85 V V FRAMP VTRI_C = 1.4V 84 100 116 KHz FRAMP_HI VTRI_C = 2.25V 170 200 256 KHz VDD = 3V VDD = 3V GBD 200 300 45 1 400 mV mV µS 200 Hz Ramp Generator Oscillation Frequency – Nominal Ramp Generator Oscillation Frequency – Maximum OLSNS Threshold Voltage OLSNS Hysteresis OLSNS-to-ICOMP Propagation Delay Symbol W W W . Microsemi . COM VTH_OLSNS VH_OLSNS TD_OLSNS 2.25 V 0.75 V DIGITAL DIMMER BLOCK Auto-Frequency Detection Response BRITE Voltage Range Full-Brightness Brite Input Voltage Full-Darkness Brite Input Voltage Copyright 2000 Rev. 1.0, 2001-03-20 40 FR_FVERT VTH_FVERT RFVERT VP_VCO VV_VCO FR_VCO_I_SRC FX_VCO TD_AFD Design Reference Only Design Reference Only VPD_CR = 3V, VDD = 3V AFC_C = 0V, CVCO = 0.01µF -6.3 FVERT Frequency is 200Hz, VDD = 3V VR_BRITE VBRITE_FULL VBRT_POS = VDD or float; BRITE = 2.5V VBRT_POS = 0V, BRITE = 0.5V VBRITE_DARK VBRT_POS = VDD or float, BRITE = 0.5V VBRT_POS = 0V, BRITE = 2.5V VDD/2 50 2.5 0.65 -5.8 250 -5.3 1000 0 2.35 2.35 0.35 0.35 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 2.5 2.5 0.5 0.5 V kΩ V V µA Hz ms VDD 2.65 2.65 0.65 0.65 V V V V V Page 4 ELECTRICALS FVERT Input Frequency Capture Range FVERT Logic Threshold FVERT Input Resistance VCO Analog Output Peak Voltage VCO Analog Output Valley Voltage VCO Forced Source Current Forced VCO Oscillation Frequency A M I C R O S E M I LX1686 Digital Dimming CCFL Controller IC C O M P A N Y P RODUCTION D ATA SHEET Unless otherwise specified, the following specifications apply over the operating ambient temperature -0°C ≤ TA ≤ 85°C for the LX1686CPW and -40°C ≤ TA ≤ 85°C for the LX1686IPW except where otherwise noted. Test conditions: VDD = VDD_P = 3.0 to 5.5V, Ri = 40kΩ, CVCO = 0.01µF, CAFD = 0.22µF, CTRI = 0.83µF, CRAMP = 208pF, RRAMP = 15kΩ, CPD = 0.22µF, CPDB = 0.047µF, RPD = 110kΩ Parameter Min LX1686 Typ Max Units TD_BRITE 300 VDD/2 VDD/2 ns V V DIRECT DRIVE PWM BLOCK ISNS Threshold Voltage Range VAMP Transconductance VAMP Output Source Current VAMP Output Sink Current VAMP Output Voltage Range VSNS Threshold Voltage VCOMP Discharge Current IAMP Transconductance IAMP Output Source Current IAMP Output Sink Current IAMP Output Voltage Range VCMP Input Offset Voltage VCOMP-to-Output Propagation Delay ICMP Input Offset Voltage ICOMP-to-Output Propagation Delay Test Conditions DIGITAL DIMMING BLOCK (CONTINUED) BRITE-to-ICOMP Propagation Delay BRITE_POS Logic Threshold DIG-DIM Logic Threshold Symbol W W W . Microsemi . COM VR_ISNS GM_VAMP IS_VAMP ISK_VAMP VR_VAMP VTH_VSNS ID_VCOMP GM_IAMP IS_IAMP ISK_IAMP VR_IAMP VOS_VCMP TD_VCOMP VOS_ICMP TD_ICOMP DIG_DIM = VDD VCOMP = 1.25V VCOMP = 1.5V VCOMP = 1.5V VCOMP = VSNS VCOMP = 0.5V, VDD = 3V BRITE = 0.5 – 2.6V ICOMP = 1.5V, VDD = 3V ICOMP = 1.5V, VDD = 3V VCOMP = 1.25V, VDD = 3V VDD = 3V ICOMP = 0.5 to 2.25V, VDD = 3V BRITE = 1.25V, RAMP_C = 2V, VDD = 3V 0 10 15 0 1.12 0.8 70 -15 20 0 -10 -10 2.5 400 50 70 1.25 1.5 200 -40 60 3 250 3 1100 110 120 VDD 1.38 10 700 -80 100 VDD 10 500 10 V µmho µA µA V V mA µmho µA µA V mV ns mV ns OUTPUT BUFFER BLOCK Output Sink Current ISK_OUTBUF Output Source Current ISOUT_BUF AOUT, BOUT = VDD = 3V AOUT, BOUT = 1V, VDD = 3V AOUT, BOUT = 0V, VDD = 3V AOUT, BOUT = 2V, VDD = 3V 25 20 -35 -20 45 35 -50 -40 85 85 85 85 mA mA mA mA 1.02 V µA kΩ V V mV mV BIAS CONTROL BLOCK Voltage at Pin I_R Pin I_R Maximum Source Current VBG Output Resistance ENABLE Logic Threshold – 3V ENABLE Logic Threshold – 5.5V ENABLE Threshold Hysteresis – 3V ENABLE Threshold Hysteresis – 5.5V VIR IMAX_IR RO_VBG VEN3V VEN5.5 VH_EN3 VH_EN5.5 .975 Design Reference Only Design Reference Only VDD = 3V VDD = 5.5V 1.5 2.7 50 10 1.9 3.2 450 350 2.4 3.6 ELECTRICALS Copyright 2000 Rev. 1.0, 2001-03-20 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 5 A M I C R O S E M I LX1686 Digital Dimming CCFL Controller IC C O M P A N Y P RODUCTION D ATA SHEET W W W . Microsemi . COM C ICO M P C VC O M P BR T IS N S VSN S D im m in g C o n tro l O u tp u t D riv e rs IC O M P VC O M P PD _C R PW M C o n tro lle rs R PD C PD N Voltage Error Am p Phase D etector - C PD - Voltage C om parator + VC O VAM P 1.25V FV ER T IA M P Auto Freq. D etect IC O M P Q 0.25- 2.25V C LK OUT 2.5V - RAM P_DO UT + BO UT B C urrent C om parator 0.5 - 2.5V VC O _C AO UT VC O M P C urrent Error A m p VD D _P A Q + + AF D _C C AF D O utput Steering Logic 0V VSS _P B ia s G en era to r, U V L O , a n d V R EF VD D EN A → + C VC O PW R _G D Burst C om parator 2.50V EN ABLE VD D _SW I_R BR IT E Ri 50k VSS 50k EN A - T riangle W ave G en. VD D VD D 1.5V + 300m V 255m V Ignite O pen Lam p C om parator 0-3V BR T _PO S D IG _D IM R AM P_C C R AM P R AM P_R R R AM P 2 BLOCK DIAGRAM PW M Ram p G e n e ra to r T R I_C O LSN S R R AM P 1 C T RI VD D Copyright 2000 Rev. 1.0, 2001-03-20 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 6 A M I C R O S E M I LX1686 Digital Dimming CCFL Controller IC C O M P A N Y P RODUCTION D ATA SHEET PW W W W . Microsemi . COM 24-Pin Thin Small Shrink Outline (TSSOP) Dim 3 2 1 P E F D E A H SE AT IN G P LA N E B G L C M A B C D E F G H L M P *LC MILLIMETERS MIN MAX 0.85 0.95 0.19 0.30 0.09 0.20 7.70 7.90 4.30 4.50 0.65 BSC 0.05 0.15 – 1.10 0.50 0.75 0° 8° 6.25 6.50 – 0.10 INCHES MIN MAX 0.033 0.037 0.007 0.012 0.0035 0.008 0.303 0.311 0.169 0.177 0.025 BSC 0.002 0.005 – .0433 0.020 0.030 0° 8° 0.246 0.256 – 0.004 Note: 1. Dimensions do not include mold flash or protrusions; these shall not exceed 0.155mm(.006”) on any side. Lead dimension shall not include solder coverage. MECHANICALS Copyright 2000 Rev. 1.0, 2001-03-20 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 7 A M I C R O S E M I C O M P A N Y LX1686 Digital Dimming CCFL Controller IC P RODUCTION D ATA SHEET W W W . Microsemi . COM NOTES PRODUCTION DATA – Information contained in this document is proprietary to LinFinity and is current as of publication date. This document may not be modified in any way without the express written consent of LinFinity. Product processing does not necessarily include testing of all parameters. LinFinity reserves the right to change the configuration and performance of the product and to discontinue product at any time. Copyright 2000 Rev. 1.0, 2001-03-20 Microsemi Linfinity Microelectronics Division 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 Page 8