ADD8706

16 V 5 + 1-Channel Operational Amplifier ADD8706 FEATURES Single-supply operation: 4.5 V to 16.5 V Upper/lower buffers swing to VS/GND Continuous output current: 35 mA VCOM peak output current: 250 mA Offset voltage: 15 mV Slew rate: 6 V/µs Unity gain stable with large capacitive loads Supply current: 750 µA per amplifier PIN CONFIGURATION +IN A 1 +IN B 2 +IN C 3 +IN D 4 +IN E 5 V+ 6 +IN F 7 16 OUT A 15 OUT B 14 OUT C ADD8706 13 OUT D 12 OUT E 11 V– 10 NC 04352-0-001 –IN F 8 9 OUT F APPLICATIONS TFT LCD monitor panels TFT LCD notebook panels Communications equipment Portable instrumentation Electronic games ADC/DAC buffer NC = NO CONNECT Figure 1. 16-Lead TSSOP GENERAL DESCRIPTION The ADD8706 is a single-supply, 5-channel buffer with a separate VCOM amplifier that has been optimized for today’s low cost TFT LCD notebook and monitor panels. The top and bottom channels swing to the top/bottom rails, respectively, and can be used as end-point gamma references. The middle channels are ideal for midpoint gamma references. The VCOM amplifier provides ver y high continuous and peak currents. All channels have excellent transient response as well as high slew rate and capacitive load drive capability. The ADD8706 is specified over the –40°C to +85°C temperature range. The ADD8706 is available in a 16-lead TSSOP package. Table 1. Input Output Characteristics Channel A B C D E F VIH VS VS – 1.7 V VS – 1.7 V VS – 1.7 V VS – 1.7 V VS – 1.7 V VIL GND + 1.7 V GND GND GND GND GND IO (mA) 15 15 15 15 15 35 ISC (mA) 150 150 150 150 150 250 Rev. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.326.8703 © 2003 Analog Devices, Inc. All rights reserved. ADD8706 TABLE OF CONTENTS Electrical Characteristics ................................................................. 3 Absolute Maximum Ratings............................................................ 5 ESD Caution .................................................................................. 5 Typical Performance Characteristics ............................................. 6 Application Information .................................................................. 9 Theory.............................................................................................9 Input/Output Characteristics ......................................................9 Important Note ..............................................................................9 Outline Dimensions ....................................................................... 11 Ordering Guide .......................................................................... 11 REVISION HISTORY Revision 0: Initial Version Rev. 0 | Page 2 of 12 ADD8706 ELECTRICAL CHARACTERISTICS Table 2. VS = 16 V, VCM = VS/2, TA @ 25 °C, unless otherwise noted Parameter SUPPLY CHARACTERISTICS Supply Voltage Power Supply Rejection Ratio Total Supply Current INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Bias Current Input Offset Current Amplifier F Common-Mode Rejection Ratio Amplifier F Input Impedance Input Capacitance OUTPUT CHARACTERISTICS Output Voltage High (A) Optimized for High Swing Output Voltage High (B to D) Optimized for Midrange Output Voltage High (E) Optimized for Low Swing Output Voltage High (F) Optimized for VCOM Output Voltage Low (A) Optimized for High Swing Output Voltage Low (B–D) Optimized for Midrange Output Voltage Low (E) Optimized for Low Swing Output Voltage Low (F) Optimized for VCOM Continuous Output Current (A to E) Continuous Output Current (F) Peak Output Current (A to E) Peak Output Current (F) Symbol VS PSRR ISY Condition Min 4.5 70 Typ Max 16 90 4.5 5.4 6 15 1100 1500 100 250 Unit V dB mA mA mV µV/°C nA nA nA nA dB kΩ pF V V V V V V V V V V V V V V V mV mV mV mV mV mV mV mV mV mA mA mA mA VS = 4 V to 17 V, –40°C ≤ TA ≤ +85°C VO = VS/2, No Load –40°C ≤ TA ≤ +85°C VOS ∆VOS/∆T IB IOS CMRR ZIN CIN VOH –40°C ≤ TA ≤ +85°C –40°C ≤ TA ≤ +85°C 2 10 400 10 –40°C ≤ TA ≤ +85°C –40°C ≤ TA ≤ +85°C VCM = 0 to (VS – 1.7 V) 54 95 400 1 15.99 15.85 14 13.985 14 13.99 15.995 15.9 1.70 1.71 5 200 5 80 5 50 15 35 50 200 VOH VOH VOH VOL VOL VOL VOL IOUT IOUT IPK IPK VIN = 16 V, IL = 100 µA VIN = 16 V, IL = 5 mA –40°C ≤ TA ≤ +85°C VIN = 14 V, IL = 100 µA VIN = 14 V, IL = 5 mA –40°C ≤ TA ≤ +85°C VIN = 14 V, IL = 100 µA VIN = 14 V, IL = 5 mA –40°C ≤ TA ≤ +85°C VIN = 16 V, IL = 100 µA VIN = 16 V, IL = 5 mA –40°C ≤ TA ≤ +85°C VIN = 1.7 V, IL = 100 µA VIN = 1.7 V, IL = 5 mA –40°C ≤ TA ≤ +85°C VIN = 0 V, IL = 100 µA VIN = 0 V, IL = 5 mA –40°C ≤ TA ≤ +85°C VIN = 0 V, IL = 100 µA VIN = 0 V, IL = 5 mA –40°C ≤ TA ≤ +85°C VIN = 0 V, IL = 100 µA VIN = 0 V, IL = 5 mA –40°C ≤ TA ≤ +85°C V S = 16 V V S = 16 V V S = 16 V V S = 16 V 15.75 15.65 13.90 13.85 13.9 13.85 15.8 15.75 1.730 1.725 300 350 200 300 150 250 Rev. 0 | Page 3 of 12 ADD8706 Parameter TRANSFER CHARACTERISTICS Amplifier Gain Buffer Gain Buffer Gain Linearity DYNAMIC PERFORMANCE Slew Rate Bandwidth Phase Margin Channel Separation NOISE PERFORMANCE Voltage Noise Density Current Noise Density Symbol AVO AVCL NL SR BW Øo Condition RL = 2 kΩ, VO = 0.5 to (VS – 2 V) R L = 2 kΩ –40°C ≤ TA ≤ +85°C RL = 2kΩ, VO = 0.5 to (VS – 0.5 V) RL = 2 kΩ, CL = 200 pF –3 dB, RL = 2 kΩ, CL = 40 pF RL = 2 kΩ, CL = 40 pF Min 1 0.995 0.995 Typ 10 0.9985 0.9980 0.01 6 6 55 75 26 25 0.8 Max Unit V/mV V/V V/V % V/µs MHz Degrees dB nV/√Hz nV/√Hz pA/√Hz 1.005 1.005 4 en in f = 1 kHz f = 10 kHz f = 10 kHz Rev. 0 | Page 4 of 12 ADD8706 ABSOLUTE MAXIMUM RATINGS Table 3. ADD8706 Stress Ratings* Parameter Supply Voltage (VS) Input Voltage Differential Input Voltage Storage Temperature Range Operating Temperature Range Junction Temperature Range Lead Temperature Range ESD Tolerance (HBM) Rating 18 V −0.5 V to VS + 0.5 V VS –65°C to +150°C –40°C to +85°C –65°C to +150°C 300°C ±1500 V Table 4. Package Characteristics Package Type 16-Lead TSSOP (RU) θJA1 180 θJC 35 Unit °C/W 1 θJA is specified for worst-case conditions, i.e., θJA is specified for devices soldered onto a circuit board for surface-mount packages. *Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only ; functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ESD CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid per formance degradation or loss of functionality. Rev. 0 | Page 5 of 12 ADD8706 TYPICAL PERFORMANCE CHARACTERISTICS 70 60 50 40 30 20 10 04532-0-025 VS = 16V 18 16 VS = 16V INPUT OFFSET CURRENT (nA) 14 12 10 8 6 4 2 0 –60 04352-0-028 QUANTITY OF AMPLIFIERS 0 –10 –8 –6 –4 –2 0 2 4 INPUT OFFSET VOLTAGE (mV) 6 8 10 –40 –20 0 20 40 TEMPERATURE (°C) 60 80 100 Figure 2. Input Offset Voltage, VS = 16 V Figure 5. Input Offset Current vs. Temperature 35 30 VS = 16V 10k VS = 4.5V SINK A 1k QUANTITY OF AMPLIFIERS 25 20 15 10 5 04352-0-026 ∆OUTPUT VOLTAGE (mV) B, C, D 100 F 10 E 1 0 0 14 28 42 56 TCVOS (µV/°C) 70 84 98 0.1 0.001 0.01 0.1 1 LOAD CURRENT (mA) 10 100 Figure 3. Input Offset Voltage Drift, VS = 16 V Figure 6. Output Sink Voltage vs. Load Current, All Channels 400 A 200 10k VS = 16V VS = 4.5V SOURCE B, C, D, E 1k INPUT BIAS CURRENT (nA) 0 ∆OUTPUT VOLTAGE (mV) 100 F –200 10 A –400 E B –600 F 04352-0-027 1 –800 –60 –40 –20 0 20 40 TEMPERATURE (°C) 60 80 100 0.1 0.001 0.01 0.1 1 LOAD CURRENT (mA) 10 100 Figure 4. Input Bias Current vs. Temperature Figure 7. Output Source Voltage vs. Load Current, All Channels Rev. 0 | Page 6 of 12 04352-0-015 C D 04352-0-013 ADD8706 10k VS = 16V SINK ∆OUTPUT VOLTAGE (mV) 0.76 0.75 0.74 0.73 0.72 0.71 0.70 0.69 –60 VS = 16V 1k 100 B, C, D 10 E F 1 SUPPLY CURRENT/AMPLIFIER (mA) A 0.1 0.001 0.01 0.1 1 LOAD CURRENT (mA) 10 100 04352-0-014 –40 –20 0 20 40 TEMPERATURE (°C) 60 80 100 Figure 8. Output Sink Voltage vs. Load Current, All Channels Figure 11. Supply Current vs. Temperature 10k POWER SUPPLY REJECTION RATIO (dB) 120 VS = 16V SOURCE 1k ∆OUTPUT VOLTAGE (mV) B, C, D, E VS = 16V 100 80 –PSRR 60 +PSRR 40 100 10 A F 1 20 0.1 0.001 04352-0-016 0.01 0.1 1 LOAD CURRENT (mA) 10 100 0 100 1k 10k 100k 1M 10M FREQUENCY (Hz) Figure 9. Output Source Voltage vs. Load Current, All Channels Figure 12. PSRR vs. Frequency 0.9 140 VS = 16V COMMON-MODE REJECTION (dB) SUPPLY CURRENT PER AMPLIFIER (mA) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 04352-0-022 120 100 80 60 40 20 0 100 04352-0-010 0 0 2 4 6 8 10 12 SUPPLY VOLTAGE (V) 14 16 18 1k 100k 10k FREQUENCY (Hz) 1M 10M Figure 10. Supply Current vs. Supply Voltage Figure 13. CMRR vs. Frequency Rev. 0 | Page 7 of 12 04352-0-018 04352-0-029 ADD8706 100 VS = 16V RL = 10kΩ CL = 40pF 45 PHASE SHIFT (Degrees) OVERSHOOT (%) 0 100 90 80 70 60 –OS 50 +OS 40 30 20 10 04352-0-012 80 VS = ±16V VIN = 100mV AV = 1 RL = 10kΩ 60 GAIN (dB) 90 40 135 20 180 0 –20 1k 10k 100k 1M FREQUENCY (Hz) 10M 225 100M 0 10 100 CAPACITIVE LOAD (pF) 1k Figure 14. Frequency vs. Gain and Shift Figure 17. Overshoot vs. Capacitive Load 100 80 60 40 100pF GAIN (dB) VS = 16V RL = 10kΩ VS = 16V RL = 2kΩ CL = 100pF 20 0 50pF –20 540pF –40 1040pF –60 –80 VOLTAGE (50mV/DIV) –100 100k 1M 10M FREQUENCY (Hz) 100M 04352-0-008 TIME (1µs/DIV) Figure 15. Gain vs. Capacitive Load Figure 18. Small-Signal Transient Response 500 450 400 350 300 250 200 150 CH. F 100 50 1k 100k 10k FREQUENCY (Hz) 1M 10M 04352-0-013 AV = 1 VS = 16V = RL = 2kΩ CL = 100pF 0 100 04352-0-005 VOLTAGE (2V/DIV) IMPEDANCE (Ω) CH. A–E TIME (1µs/DIV) Figure 16. Impedance vs. Frequency Figure 19. Large Signal Transient Response Rev. 0 | Page 8 of 12 04352-0-021 04352-0-020 ADD8706 APPLICATION INFORMATION THEORY The ADD8706 is designed for use in LCD gamma correction circuits. This is an ideal on-chip solution for low-end panels. It provides five gamma voltages and a VCOM output. These gamma voltages provide the reference voltages for the column driver RDACs. Due to the capacitive nature of LCD panels, it is necessar y for these drivers to provide high capacitive load drive. The VCOM output is the center voltage common to all the LCD pixels. The VCOM circuit is common to all the pixels in the panel. This requires the VCOM driver to supply continuous currents up to 35 mA. The outputs of the buffers and amplifier have been designed to match the performance needs of the gamma correction and VCOM circuits. All have rail-to-rail outputs, but the current drive capabilities differ. The difference in current drive and input voltage range determine the buffer and amplifier use. Buffer A has an NPN emitter-follower input stage, which provides an input range that includes the top rail, but is limited to 1.7 V away from the bottom rail. It is designed to source 15 mA of continuous current, making this buffer ideal for providing the top voltage on the RDAC string. Buffers B, C, and D use a single-supply PNP input stage with an intermediate common-mode voltage range. The output was designed to sink or source up to 15 mA of continuous current. The limited input range and equivalent sink and source current make these buffers suitable for the middle voltage ranges on the RDAC string. Buffer E also uses a single-supply PNP input stage, but the output is designed to sink only up to 15 mA of continuous current. This buffer is designed for the RDAC’s lower range. Amplifier F is designed with an input range limited to midscale applications. It is capable of delivering 35 mA of continuous current. These qualities make Amplifier F suitable for VCOM applications. INPUT/OUTPUT CHARACTERISTICS The ADD8706 has five buffers specifically designed for the needs of an LCD panel. Figure 20 shows a typical gamma correction cur ve for a normally white twisted nematic LCD panel. The symmetric cur ve comes from the need to reverse the polarity on the LC pixels to avoid “burning” in the image. Therefore, the application requires gamma voltages that come close to both supply rails. To accommodate this transfer function, the five ADD8706 buffers have been designed with three different buffer designs in one package. VDD VG1 VG2 GAMMA VOLTAGE IMPORTANT NOTE Because of the asymmetric nature of Buffers A and E, care must be taken to connect an input that forces the amplifiers to operate in their most productive output states. Buffer A has ver y limited sink capabilities, while Buffer E does not source well. Set the Buffer A input to enable the amplifier output to source current and set the Buffer E input to force a sinking output current. This means making sure the input is above the midpoint of the common-mode input range for Buffer A and below the midpoint for Buffer E. Mathematically speaking, make sure VIN > VS/2 for Buffer A and VIN < VS/2 for Buffer E. Figure 21 shows an application using the ADD8706 to generate 10 gamma outputs. Note that the five outputs are routed through another resistor network to generate the extra five output voltages, which feed into the column driver. VG3 VG4 VG5 VG6 VG7 VG8 VG9 VG10 VSS 0 16 32 GRAY SCALE BITS 48 64 04352-0-003 Figure 20. LCD Gamma Correction Curve The nature of LCD panels introduces a large amount of parasitic capacitance from the column drivers as well as the capacitance associated with the liquid cr ystals via the common plane. This makes capacitive drive capability an important factor when designing the gamma correction circuit. Rev. 0 | Page 9 of 12 ADD8706 VDD ADD8706 A COLUMN DRIVER GAMMA 1 GAMMA 2 B GAMMA 3 GAMMA 4 C GAMMA 5 GAMMA 6 D GAMMA 7 GAMMA 8 E VDD VCOM GAMMA 9 GAMMA 10 F VCOM Figure 21. ADD8706 Application Circuit Rev. 0 | Page 10 of 12 00000-x-000 ADD8706 OUTLINE DIMENSIONS 5.10 5.00 4.90 16 9 4.50 4.40 4.30 1 8 6.40 BSC PIN 1 1.20 MAX 0.15 0.05 0.65 BSC 0.20 0.09 SEATING PLANE 8° 0° 0.30 0.19 COPLANARITY 0.10 0.75 0.60 0.45 COMPLIANT TO JEDEC STANDARDS MO-153AB Figure 22. 16-Lead Thin Shrink Small Outline Package [ TSSOP] (RU) Dimensions shown in millimeters ORDERING GUIDE Model1 ADD8706ARUZ ADD8706ARUZ-REEL Temperature Range −40°C to +85°C −40°C to +85°C Package Description 16-Lead TSSOP 16-Lead TSSOP Package Option RU-16 RU-16 1 Z = Pb-free part. Rev. 0 | Page 11 of 12 ADD8706 NOTES © 2003 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C04352–0–10/03(0) Rev. 0 | Page 12 of 12