LMC6009 LMC6009 9 Channel Buffer Amplifier for TFT-LCD Literature Number: SNOS786A LMC6009 9 Channel Buffer Amplifier for TFT-LCD General Description Features The LMC6009 is a CMOS integrated circuit that buffers 9 reference voltages for gamma correction in a Thin Film Transistor Liquid Crystal Display (TFT-LCD). Guaranteed to operate at both 3.3V and 5V supplies, this integrated circuit contains nine, independent unity gain buffers that can source 130 mA into a capacitive load without oscillation. The LMC6009 is useful for buffering gamma voltages into column drivers that employ the resistor-divider architecture. High output current capability and fast settling characteristics of this device improve display quality by minimizing rise time errors at the outputs of the column driver. The integration of nine buffers and a multiplexer eliminates the need for discrete buffers and a separate multiplexer (MUX) chip on the panel. The LMC6009 is available in 48-pin surface mount TSSOP. n n n n n n n n Number of inputs 3.3V and 5V operation Supply current Settling time A/B channel inputs for asymmetrical Gamma Number of outputs Number of control inputs Built-in thermal shutdown protection 18 3.5 mA 3 s 9 1 Applications n n n n n VGA/SVGA TFT-LCD drive circuits Electronic Notebooks Electronic Games Personal Communication Devices Personal Digital Assistants (PDA) Application in VGA/SVGA TFT-LCD DS012533-1 Ordering Information Package 48-pin TSSOP Temperature Range Transport Media -20C-+75C NSC Drawing MTD48 LMC6009MT LMC6009MTX (c) 2001 National Semiconductor Corporation DS012533 Tape and Reel www.national.com LMC6009 9 Channel Buffer Amplifier for TFT-LCD May 1999 LMC6009 Absolute Maximum Ratings (Note 1) Maximum Junction Temperature (TJ) Maximum Power Dissipation (PD) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance Input Voltage Supply Voltage (VDD) Operating Temperature Storage Temperature Range +150C 1.09W Operating Ratings (Note 1) 1.0 kV GND-0.3V V+ VDD+0.3VDC -0.3 to +6.5 VDC -20C to +75C -55C to +150C 2.7V VDD 5.5V DC-50 kHz Supply Voltage Frequency Thermal Resistance (JA) Derating 8.70 mW/C 3V DC Electrical Characteristics Unless otherwise specified, all limits are guaranteed for TJ = 25C, and VDD = 3.0 VDC. Symbol Parameter VDD Supply Voltage VOS Offset Voltage IB Input Bias Current VOL Output Voltage, Low VOH Output Voltage, High Conditions Min Typ Max 2.7 3.0 3.3 V 20 mV RS = 10k Units 1500 nA Amp A8 and A9 ISINK = 13 mA GND + 0.2 V Amp A1-A7 ISINK = 13 mA GND + 0.6 V Amp A1 and A2 ISOURCE = 13 mA VDD-0.2 V Amp A3-A9 ISOURCE = 13 mA VDD-0.6 V ISC Output Short Circuit Current VOUT - 1.65V (Note 1) IDD Supply Current No Load VL Load Regulation VIN = 0.3-3 VDC ISOURCE = 13 mA VIH A/B Switch Logic Voltage, High Select A VIL A/B Switch Logic Voltage, Low Select B 80 150 3.5 ISINK = 13 mA mA 5 mA -10 mV +10 mV 2 V 0.8 V A IIH A/B Switch Logic Current, High 1.5 IIL A/B Switch Logic Current, Low 1 AV Voltage Gain 0.985 A V/V Note 1: See Test Circuit (Figure 2 ) 5V DC Electrical Characteristics Unless otherwise specified, all limits are guaranteed for TJ = 25C, and VDD = 5 VDC. Symbol Parameter VDD Supply Voltage VOS Offset Voltage IB Input Bias Current VOL Output Voltage, Low VOH Output Voltage, High Conditions Typ Max Units 4.5 5 5.5 V RS = 10k 20 mV 1500 nA Amp A8 and A9 ISINK = 20 mA GND + 0.2 V Amp A1-A7 ISINK = 20 mA GND + 1.0 V Amp A1 and A2 ISOURCE = 20 mA VDD-0.2 V Amp A3-A9 ISOURCE = 20 mA VDD-1.0 V ISC Output Short Circuit Current VOUT - 1.65V (Note 1) IDD Supply Current No Load www.national.com Min 120 200 4.5 2 mA 6 mA (Continued) Unless otherwise specified, all limits are guaranteed for TJ = 25C, and VDD = 5 VDC. Symbol VL Parameter Conditions Load Regulation Max Units VIN = 0.5-4.5 VDC ISOURCE = 20 mA -10 mV ISINK = 20 mA +10 mV VIH A/B Switch Logic Voltage, High Select A VIL A/B Switch Logic Voltage, Low Select B IIH Min Typ 2 V 0.8 V A/B Switch Logic Current, High 1.5 A IIL A/B Switch Logic Current, Low 1 A AV Voltage Gain 0.985 V/V AC Electrical Characteristics Unless otherwise specified, all limits are guaranteed for TJ = 25C, and VDD = 3 VDC. Symbol Parameter Conditions Min Typ Max Units TS1 Settling Time 1 (Note 2) IDC = 13 mA (Sink/Source) 3 6 s TS2 Settling Time 2 (Note 2) IDC = 13 mA (Sink/Source) 3 6 s Note 2: See test circuits (Figure 3 , Figure 4 and Figure 5 ) DS012533-2 FIGURE 1. Rise and Fall Times at Outputs 3 www.national.com LMC6009 5V DC Electrical Characteristics LMC6009 AC Electrical Characteristics (Continued) DS012533-5 FIGURE 4. 13 mA Sink/Source DS012533-3 FIGURE 2. DS012533-6 FIGURE 5. A6-A8: 13 mA Sink/Source A9: 13 mA Sink Only DS012533-4 FIGURE 3. A1: 13 mA Source only A2-A4: 13 mA Sink/Source Description of Pins; LMC6009 www.national.com Pin 1 NC Pin 25 NC Pin 2 NC Pin 26 NC Pin 3 NC Pin 27 NC Pin 4 A1 in (A) Pin 28 NC Pin 5 A1 in (B) Pin 29 A/B Switch Pin 6 A2 in (A) Pin 30 VDD (C) Pin 7 A2 in (B) Pin 31 GND (C) Pin 8 A3 in (A) Pin 32 A9 out Pin 9 A3 in (B) Pin 33 A8 out Pin 10 A4 in (A) Pin 34 A7 out Pin 11 A4 in (B) Pin 35 A6 out Pin 12 A5 in (A) Pin 36 A5 out Pin 13 A5 in (B) Pin 37 GND (B) Pin 14 A6 in (A) Pin 38 VDD (B) Pin 15 A6 in (B) Pin 39 A4 out Pin 16 A7 in (A) Pin 40 A3 out Pin 17 A7 in (B) Pin 41 A2 out Pin 18 A8 in (A) Pin 42 A1 out Pin 19 A8 in (B) Pin 43 GND (A) Pin 20 A9 in (A) Pin 44 VDD (A) Pin 21 A9 in (B) Pin 45 NC Pin 22 NC Pin 46 NC Pin 23 NC Pin 47 NC Pin 24 NC Pin 48 NC 4 LMC6009 Block Diagram DS012533-8 FIGURE 6. Block Diagram of LMC6009 Applications Since the buffers in the LMC6009 draw extremely low bias current (1.5 A max), large resistance values can be used in the reference voltage string. This allows the power dissipation in the gamma reference circuit to be minimized. The nine buffers are guaranteed to deliver 80 mA to the load, allowing the pixel voltages of the TFT-LCD to settle very quickly. The LMC6009 is useful for buffering the nine reference voltages for gamma correction in a TFT-LCD as shown in Figure 7. The A/B channel inputs allow the user to alternate two sets of gamma references to compensate for asymmetrical Gamma characteristic during Row Inversion. The LMC6009 eliminates the need for nine external switches or an 18-to-9 multiplexer. 5 www.national.com LMC6009 Applications (Continued) DS012533-7 FIGURE 7. Column Driver (Figure 7) also draw current from the LMC6009. Thus, the actual current available for charging the panel capacitance is: Ipx = 80 mA - (VVREF1-VVREF2)/RCD Example: Below is a calculation of pixel charge time (for a black to black transition) in a VGA display operating at a vertical refresh rate of 60 Hz, with a panel capacitance of 50 pF per sub-pixel: A full black to black transition represents the maximum charging time for the panel, since it requires that the panel capacitance be driven by a 4V swing from node VREF1 (Figure 7). Total capacitive load presented to the LMC6009 is CL = 50 pF x 3 x 640 = 96 nF where VV REFn = Voltage at node VREFn, VVREF(n+1) = Voltage at node VREF(n+1), and RCD = Column driver input resistance between VREFn and VREF(n+1) Since the LMC6009 is capable of sourcing 80 mA, the pixel charging time is primarily limited only by the length of the RCD. CL time constant. To implement a high quality display, column drivers that allow the shortest possible time constant (lower values of RCD) are desirable. However, lower values of RCD result in increased system quiescent power dissipation. It is therefore important to optimize system performance by carefully considering speed vs power tradeoffs. Output current of the LMC6009 is: ISC = 80 mA Hence, slew time tSLEW = (96 nF x 4V)/80 mA = 3.07 s The total line time for a VGA system is approximately 34 s. Therefore, the LMC6009 easily meets the drive requirements for the application. The input resistance seen between the VREFn and VREF(n+1) inputs, (where n = 0 thru 8) of the www.national.com 6 LMC6009 9 Channel Buffer Amplifier for TFT-LCD Physical Dimensions inches (millimeters) unless otherwise noted All dimensions are in millimeters 48-Lead Molded Thin Shrink Small Outline Package, JEDEC NS Package Number MTD48 LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: support@nsc.com www.national.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Francais Tel: +33 (0) 1 41 91 8790 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: ap.support@nsc.com National Semiconductor Japan Ltd. Tel: 81-3-5639-7560 Fax: 81-3-5639-7507 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI's terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI 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 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. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Communications and Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP(R) Products www.dlp.com Energy and Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Video and Imaging RFID www.ti-rfid.com OMAP Mobile Processors www.ti.com/omap Wireless Connectivity www.ti.com/wirelessconnectivity TI E2E Community Home Page www.ti.com/video e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright (c) 2011, Texas Instruments Incorporated