19-3669; Rev 3; 8/07 RGBHV Driver with EMI Suppression The MAX9511 provides a complete VGA interface between a graphics controller and/or docking station. The MAX9511 has output drivers with variable electromagnetic interference (EMI) suppression for graphics video and sync (RGBHV) signals and includes external load-detection circuitry. The MAX9511 suppresses EMI emissions by limiting the slew rate (SR) rather than limiting bandwidth with fixed L-C filters. The SR controls the large-signal bandwidth without affecting the small-signal bandwidth, resulting in sharper video images, while reducing EMI. The SR of the MAX9511 provides tighter control than traditional passive L-C components, and allows the SR to track the resolution by varying an external resistor (RRX) rather than being fixed to a sub-optimal value. The load-detection circuitry of the MAX9511 automatically detects and transmits a change in load status to the input stages when an external load (monitor, docking station, or projector) is connected. The MAX9511 is compatible with the load-detection circuitry on the digital-to-analog (DAC) outputs of most video graphics controllers. The output drivers provide 6dB of gain to compensate for the 75Ω back-termination resistors, which reduce transmission line reflections. The RGBHV channels can be placed into shutdown to reduce power when no external load is connected. The MAX9511 operates from 3V and 5V supplies. The DDC circuitry performs bidirectional level translation from 3V to 5V logic levels. The MAX9511 is offered in a 24-pin QSOP package and is specified over the commercial 0°C to +70°C temperature range. Applications Features ♦ RGB Drivers with Adjustable Slew Rate for EMI Control ♦ H Sync and V Sync Drivers with Level Translation ♦ Bidirectional Level Translators for DDC Support ♦ Simultaneously Drives External Monitor/Projector and Docking Station without Analog RGB Switches—No Stub Reflections ♦ Eliminates Up to 34 External Components ♦ Small 24-Pin QSOP Package Ordering Information PART TEMP RANGE PINPACKAGE PKG CODE MAX9511CEG 0°C to +70°C 24 QSOP E24-2 MAX9511CEG+ 0°C to +70°C 24 QSOP E24-2 +Denotes a lead-free package. Simplified Block Diagram MAX9511 EMI SUPPRESSION RED_IN RED_OUT GREEN_OUT GREEN_IN BLUE_OUT BLUE_IN Notebook PCs (Laptops) Docking Stations Graphics Cards for Notebooks and Personal Computers Personal Computer Motherboards with On-Board Video Graphics Controllers LOAD-DETECT CIRCUITRY DDC_DATA_IN DDC_DATA_OUT DDC_CLK_IN DDC_CLK_OUT H_SYNC_IN H_SYNC_OUT V_SYNC_IN V_SYNC_OUT Workstations Pin Configuration appears at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX9511 General Description MAX9511 RGBHV Driver with EMI Suppression ABSOLUTE MAXIMUM RATINGS DDC_DATA_OUT to DGND .................(DDC_DATA_IN - 0.1V) to (VDD1 + 0.3V) DDC_CLK_IN to DGND ................(DDC_CLK_OUT - 0.3V) to (VDD2 + 0.3V) DDC_CLK_OUT to DGND....................(DDC_CLK_IN - 0.1V) to (VDD1 + 0.3V) DDC_DATA_OUT to DDC_DATA_IN ........................-0.1V to +6V DDC_CLK_OUT to DDC_CLK_IN.............................-0.1V to +6V Continuous Power Dissipation (TA = +70°C) 24-Pin QSOP (derate 9.5mW/°C above +70°C)..........762mW Operating Temperature Range...............................0°C to +70°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C VCC to AGND............................................................-0.3V to +6V VDD1, VDD2 to DGND ...............................................-0.3V to +6V DGND to AGND.....................................................-0.1V to +0.1V RED_IN, GREEN_IN, BLUE_IN to AGND.....-0.3V to (VCC + 0.3V) RED_OUT, GREEN_OUT, BLUE_OUT to AGND ................................................-0.3V to (VCC + 0.3V) RX to AGND................................................-0.3V to (VCC + 0.3V) H_SYNC_IN, V_SYNC_IN, SHDN to DGND ..............................................-0.3V to (VDD2 + 0.3V) H_SYNC_OUT, V_SYNC_OUT to DGND ..............................................-0.3V to (VDD1 + 0.3V) DDC_DATA_IN to DGND..............(DDC_DATA_OUT - 0.3V) to (VDD2 + 0.3V) Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VCC = 5V, VDD1 = 5V, VDD2 = SHDN = 3V, RL = 150Ω to AGND, DGND = AGND, RRX = 7kΩ to AGND, TA = 0°C to +70°C. Typical values are at TA = +25°C.) PARAMETER Supply Voltage Range SYMBOL CONDITIONS MIN TYP MAX VCC Inferred from PSRR 4.5 5.5 VDD1 Inferred from logic test 4.5 5.5 VDD2 Inferred from logic test 2.3 3.6 ICC SHDN = VDD2 RRX = 7kΩ 38 RRX = 36kΩ SHDN = DGND Quiescent Supply Current IDD1 IDD2 SHDN = VDD2 V 50 25 35 0.15 0.25 3 6 0.027 0.08 SHDN = VDD2 220 500 SHDN = DGND 26 40 0.7 0.9 SHDN = DGND UNITS mA µA VIDEO Input Voltage Range Output Black Level Voltage VIN Inferred from voltage gain VOUT,BLACK RED_IN = GREEN_IN = BLUE_IN = AGND AV 0 ≤ VIN ≤ 0.9V, RL = 75Ω Gain Matching ∆AV 0 ≤ VIN ≤ 0.9V, RL = 75Ω Input Resistance RIN Voltage Gain Output Impedance ZOUT Output Short-Circuit Current (To AGND) IOUT Load-Detection Voltage VX_IN Output Load Detection RL_OUT Power-Supply Rejection PSRR Large-Signal Bandwidth 2 0 5 65 160 mV +1.9 +2 +2.1 V/V 1 2 % 0 ≤ VIN ≤ 1V, with load 10 100 0.4V ≤ VIN ≤ 0.7V, no load -85 -74 f = 100kHz kΩ -62 Ω 40 mA 0.2 VIN = 0.4V 180 4.5V ≤ VCC ≤ 5.5V, VIN = 0.5V 40 Ω 0.64 (Note 1) VOUT = 1.6VP-P, RRX = 7kΩ V V Ω 57 dB 370 MHz _______________________________________________________________________________________ RGBHV Driver with EMI Suppression (VCC = 5V, VDD1 = 5V, VDD2 = SHDN = 3V, RL = 150Ω to AGND, DGND = AGND, RRX = 7kΩ to AGND, TA = 0°C to +70°C. Typical values are at TA = +25°C.) PARAMETER SYMBOL Slew Rate (Notes 2, 3) SR Settling Time tS Undershoot/Overshoot Linearity Error Peak Signal-to-Noise Ratio SNR Channel-to-Channel Skew ∆t PSRR Crosstalk Input Termination Switch Delay MIN TYP MAX RRX = 36kΩ, TA = +25°C 250 330 450 RRX = 7kΩ, TA = +25°C 900 1100 1300 (Notes 4, 5) tOS, tUS LE Power-Supply Rejection Ratio CONDITIONS VIN = 700mVP-P (Notes 6, 7) UNITS V/µs 0 ns ±1 % 0.036 % f = 100kHz to 100MHz, VIN = 700mVP-P 50 dB R to G to B (Note 3) 500 f = 100kHz 49 dB All hostile, f = 10MHz 55 dB 70 ns ∆tSWD 1100 ps LOGIC Input Low Level VIL H_SYNC_IN, V_SYNC_IN and SHDN Input High Level VIH H_SYNC_IN, V_SYNC_IN and SHDN IOL = 4mA Output Low Level VOL IOH = 4mA VOH 0.7 x VDD2 H_SYNC_OUT, VH_SYNC_IN = DGND 0.55 IOH = 50µA IOH = 50µA 0.4 DDC_DATA_OUT, VDDC_DATA_IN = DGND DDC_CLK_OUT, VDDC_CLK_IN = DGND H_SYNC_OUT, VH_SYNC_IN = VDD2 V_SYNC_OUT, VV_SYNC_IN = VDD2 DDC_DATA_IN, VDDC_DATA_OUT = VDD1 DDC_CLK_IN, VDDC_CLK_OUT = VDD1 DDC_DATA_OUT, VDDC_DATA_IN = VDD2 DDC_CLK_OUT, VDDC_CLK_IN = VDD2 V V V_SYNC_OUT, VV_SYNC_IN = DGND DDC_DATA_IN, VDDC_DATA_OUT = IOL = 50µA DGND DDC_CLK_IN, VDDC_CLK_OUT = DGND IOL = 3mA Output High Level 0.3 x VDD2 V 0.5 VDD1 - 1.5 VDD2 - 0.4 V VDD1 - 1.5 SYNC Output Resistance RSO 35 55 85 Ω SHDN Pulldown Resistance RSD 225 330 500 kΩ SYNC Input Resistance RSI 30 47 70 kΩ 2 3 4 3.0 4.7 6.5 DDC Pullup Resistance RPO DDC_DATA_OUT, DDC_CLK_OUT RPI DDC_DATA_IN, DDC_CLK_IN kΩ _______________________________________________________________________________________ 3 MAX9511 ELECTRICAL CHARACTERISTICS (continued) ELECTRICAL CHARACTERISTICS (continued) (VCC = 5V, VDD1 = 5V, VDD2 = SHDN = 3V, RL = 150Ω to AGND, DGND = AGND, RRX = 7kΩ to AGND, TA = 0°C to +70°C. Typical values are at TA = +25°C.) PARAMETER SYMBOL Rise/Fall Time CONDITIONS tPLH, tPHL MIN TYP CSYNC = 47pF, TA = +25°C All SYNC outputs (Notes 2, 3) tR/tF Propagation Delay MAX UNITS 100 ns 22 ns 7 CSYNC = 470pF, TA = +25°C 50 70 DDC only, CL = 47pF 400 SYNC, CSYNC = 47pF, TA = +25°C (Notes 3, 8) 12 Enable Time VIN = 0.7VP-P, SHDN from DGND to VDD2, outputs settle to ±1% of final value 1200 ns Disable Time VIN = 0.7VP-P, SHDN from VDD2 to DGND, outputs settle to ±1% of final value 400 ns Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: This is the voltage at which the input termination switches; VIN > VX_IN = switch open, VIN < VX_IN = switch closed. Measured between the 10% to 90% points on rising or falling edge. Not production tested. Guaranteed by design. Measured from the END of overshoot/undershoot to ±5% of final value. VIN = 700mV with a rise time >1ns. Linearity error is the maximum difference between the actual and measured output of a video ramp. Done in accordance with VESA Test Procedure, Version 1, 6/11/2001. Note 7: Linearity error measured as percentage of full scale. Note 8: Propagation delay is the time difference between the VDD2 / 2 input crossing and the 1.4V output crossing. Typical Operating Characteristics (VCC = 5V, VDD1 = 5V, VDD2 = 3V, RL = 150Ω to AGND, RRX = 7kΩ to AGND, TA = +25°C, unless otherwise noted.) 1 0.4 3 0.3 2 1 0 -1 0.1 -1 -2 -3 GAIN (dB) 0.2 GAIN (dB) 0 0 -0.1 -2 -0.2 -4 -5 -0.3 -5 -6 -0.4 -6 -7 -0.5 -7 1 10 FREQUENCY (MHz) 100 1000 0.1 1 10 FREQUENCY (MHz) 100 1000 RRX = 5kΩ -3 -4 0.1 4 LARGE-SIGNAL BANDWIDTH vs. FREQUENCY vs. RRX MAX9511 toc02 VOUT = 1.6VP-P TA = TMIN to TMAX 2 0.5 MAX9511 toc01 3 LARGE-SIGNAL GAIN FLATNESS vs. FREQUENCY MAX9511 toc03 LARGE-SIGNAL BANDWIDTH vs. FREQUENCY GAIN (dB) MAX9511 RGBHV Driver with EMI Suppression RRX = 20kΩ RRX = 35kΩ RRX = 50kΩ 0.1 1 10 FREQUENCY (MHz) _______________________________________________________________________________________ 100 1000 RGBHV Driver with EMI Suppression LARGE-SIGNAL GAIN FLATNESS vs. FREQUENCY vs. RRX SMALL-SIGNAL BANDWIDTH vs. FREQUENCY vs. RRX 1 0.4 0.3 0.2 -1 0.1 GAIN (dB) 0 -2 RRX = 5kΩ -3 RRX = 20kΩ -4 -5 RRX = 35kΩ -6 RRX = 50kΩ MAX9511 toc05 2 GAIN (dB) 0.5 MAX9511 toc04 3 RRX = 5kΩ 0 RRX = 20kΩ -0.1 RRX = 35kΩ -0.2 -0.3 RRX = 50kΩ -0.4 -0.5 -7 0.1 1 10 100 1000 0.1 10,000 1 ALL-HOSTILE CROSSTALK vs. FREQUENCY -30 -40 TA = +85°C TA = 0°C, +25°C -70 1000 MAX9511 toc07 -20 OFF-ISOLATION (dB) -20 -80 -40 -60 -80 -100 -90 -120 -100 1 10 100 0.1 1000 1 10 100 1000 FREQUENCY (MHz) FREQUENCY (MHz) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY TRANSIENT RESPONSE MAX9511 toc08 0 MAX9511 toc09 0.1 -10 VIN 500mV/div 0V -20 PSRR (dB) CROSSTALK (dB) 0 MAX9511 toc06 -10 -60 100 OFF-ISOLATION vs. FREQUENCY 0 -50 10 FREQUENCY (MHz) FREQUENCY (MHz) TA = +70°C -30 -40 VOUT 1V/div -50 OV -60 TA = 0°C TA = +25°C -70 2ns/div 0.01 0.1 1 10 100 1000 FREQUENCY (MHz) _______________________________________________________________________________________ 5 MAX9511 Typical Operating Characteristics (continued) (VCC = 5V, VDD1 = 5V, VDD2 = 3V, RL = 150Ω to AGND, RRX = 7kΩ to AGND, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = 5V, VDD1 = 5V, VDD2 = 3V, RL = 150Ω to AGND, RRX = 7kΩ to AGND, TA = +25°C, unless otherwise noted.) DDC_IN TO DDC_OUT PULSE RESPONSE SYNC PULSE RESPONSE MAX9511 toc10 MAX9511 toc11 RL = 2.2kΩ RL = 100kΩ CL = 47pF INPUT 1V/div INPUT 1V/div 0V OUTPUT 1V/div CL = 47pF CL = 150pF CL = 220pF CL = 330pF CL = 510pF 0V OUTPUT 2V/div tR = 250ns tF = 30ns 0V 0V 50µs/div 500ns/div POWER-SUPPLY CURRENT vs. TEMPERATURE (ICC) DDC_OUT TO DDC_IN PULSE RESPONSE MAX9511 toc12 POWER-SUPPLY CURRENT (mA) 48 INPUT 2V/div 0V OUTPUT 1V/div MAX9511 toc13 50 RL = 100kΩ CL = 47pF tR = 280ns tF = 4ns 46 44 42 40 38 36 34 32 0V 30 25 0 500ns/div 50 TEMPERATURE (°C) OUTPUT IMPEDANCE vs. FREQUENCY OUTPUT IMPEDANCE (Ω) 12 11 10 9 8 7 6 MAX9511 toc14 MAX9511 RGBHV Driver with EMI Suppression 5 4 3 2 1 0 10k 100k 1M 10M 100M 1G FREQUENCY (Hz) 6 _______________________________________________________________________________________ 75 RGBHV Driver with EMI Suppression 2.5 2.0 1.5 MEAN 200 150 MEAN - 3 x SIGMA 100 -66 -68 -70 -72 -78 IDD2 0 0 25 -64 -76 50 0 0.4V ≤ VIN ≤ 0.7V NO LOAD -62 -74 1.0 0.5 MAX9511 toc17 MEAN + 3 x SIGMA 250 -60 RESISTANCE (Ω) 3.0 OFFSET VOLTAGE (mV) POWER-SUPPLY CURRENT (mA) IDD1 300 MAX9511 toc16 SHDN = VDD2 MAX9511 toc15 4.0 3.5 INPUT RESISTANCE vs. TEMPERATURE OUTPUT OFFSET vs. TEMPERATURE (VOUT,BLACK) POWER-SUPPLY CURRENT vs. TEMPERATURE (IDD1, IDD2) 50 75 -80 0 25 50 75 25 0 TEMPERATURE (°C) TEMPERATURE (°C) 50 75 TEMPERATURE (°C) Pin Description PIN NAME 1 VCC 2 GREEN_IN FUNCTION Analog Power Supply Green Video Input 3, 20, 22, 24 AGND Analog Ground 4 RED_IN Red Video Input 5 BLUE_IN 6 RX 7 SHDN 8 DDC_DATA_IN 9 DDC_CLK_IN 10 H_SYNC_IN 11 V_SYNC_IN 12 VDD2 SYNC/DDC 3V Supply 13 VDD1 SYNC/DDC 5V Supply. Supplies 5V to SYNC and DDC output circuitry. Blue Video Input Slew-Rate Control. Connect an external resistor from RX to AGND. Active-Low Shutdown. For normal operation connect to VDD2. SHDN is internally pulled to DGND. DDC Data Input. Defaults to VDD2 through an internal pullup resistor. DDC Clock Input. Defaults to VDD2 through an internal pullup resistor. Horizontal SYNC Input. Defaults to AGND through an internal pulldown resistor. Vertical SYNC Input. Defaults to AGND through an internal pulldown resistor. 14 V_SYNC_OUT Vertical Sync Output 15 H_SYNC_OUT Horizontal Sync Output 16 DDC_CLK_OUT 17 DDC Clock Output. Defaults to VDD1 through an internal pullup resistor. DDC_DATA_OUT DDC Data Output. Defaults to VDD1 through an internal pullup resistor. 18 DGND 19 BLUE_OUT Digital Ground Blue Video Output 21 RED_OUT Red Video Output 23 GREEN_OUT Green Video Output _______________________________________________________________________________________ 7 MAX9511 Typical Operating Characteristics (continued) (VCC = 5V, VDD1 = 5V, VDD2 = 3V, RL = 150Ω to AGND, RRX = 7kΩ to AGND, TA = +25°C, unless otherwise noted.) RGBHV Driver with EMI Suppression MAX9511 Block Diagram VCC MAX9511 RISENSE VY GREEN_IN GREEN_OUT -75Ω VX RISENSE VY RED_IN RED_OUT -75Ω VX RISENSE VY Detailed Description The MAX9511 solves several difficult problems in interfacing a video graphics controller to a VGA port and/or the docking station connector. First, there is a trade-off between video quality and EMI. The usual method for reducing EMI is to insert a fixed-frequency LC π-filter between the video DAC output and the connector. Given the large component variation of the capacitors and inductors, the frequency response is sharply reduced to meet EMI requirements. As a result, video quality suffers making sharp transitions in the video soft. The MAX9511 video drivers have a variable slew rate, which limits electromagnetic emissions and can be adjusted by an external resistor. As a result, the slew rate of the MAX9511 can be varied to reduce electromagnetic emissions at a given resolution, maximizing video quality. Since the slew rate is variable and set by a resistor instead of fixed by capacitors and inductors, video performance and electromagnetic emissions are consistent during production. The MAX9511 also has horizontal and vertical sync output drivers, bidirectional level translators for DDC support, and external load-detection circuits that correctly transfer information about the external load to the video graphics controller. Load Detection BLUE_IN BLUE_OUT -75Ω RX VX VDD1 VDD2 SHDN RPI RPI RPO RB DDC_DATA_IN DDC_DATA_OUT RB RPO DDC_CLK_IN DDC_CLK_OUT RSO H_SYNC_IN H_SYNC_OUT RSI RSO V_SYNC_IN RSI AGND 8 DGND V_SYNC_OUT Most notebook computers implement a power-saving load-detection circuit that disables the external monitor output when no monitor is plugged into the rear panel VGA connector as shown in Figure 1. Upon startup or on command, the video controller generates a sequence of detection pulses out of the current DAC shown, that results in an output voltage of above 315mV when an external monitor (RL) is connected, and above 630mV when disconnected. If the monitor is disconnected at the time of the pulse, the comparator inside the notebook trips and disables the video. When the monitor is plugged in, the resulting pulse will not trip the comparator and the video is enabled. If the lowpass filter is simply replaced with an amplifier, the monitor termination RL is isolated from the video controller and the conventional load-detection scheme does not work. For this reason, the MAX9511 includes the load-detection circuit. When RL is connected (i.e., the monitor is plugged in) to the output of the MAX9511, the internal load-detection circuit disconnects the synthesized -75Ω resistor from the input. The resulting 37.5Ω resistance at the DAC output indicates to the DAC’s internal load-detection circuit that the monitor is plugged in. Removing RL (i.e., disconnecting the monitor) causes the MAX9511’s load-detection circuit to connect the synthesized -75Ω _______________________________________________________________________________________ RGBHV Driver with EMI Suppression MAX9511 MONITOR VIDEO CONTROLLER LOWPASS FILTER FOR EMI SUPPRESSION IOUT RT 75Ω REF RL 75Ω CURRENT DAC Figure 1. Conventional Load-Detection Scheme VIDEO CONTROLLER MONITOR RISENSE MAX9511 VY VIS IOUT G=2 OUT REF RT 37.5Ω RT 75Ω RL 75Ω -75Ω CURRENT DAC VX Figure 2. Load-Detection Scheme with MAX9511 resistor to the input. This results in an equivalent impedance of 75Ω at the DAC output, which indicates to the video controller’s internal load-detection circuit that the load is disconnected and the video controller shuts down the video output. Figure 2 and Table 1 demonstrate how the MAX9511 load-detection circuit operates in conjunction with the video controller load detection. Output Video Signal Level Shift The video signal at the MAX9511 output is shifted upwards by approximately 240mV from the input to keep the output stage of the video driver in a linear region of operation. At the connector, the video signal is attenuated by 6dB, canceling the 6dB gain of the video driver. The 240mV level shift is also attenuated by 6dB, and hence the actual video signal seen by the load is only 120mV higher than the video signal at the input of the MAX9511. Monitors and other display devices AC-couple the input signal so the 120mV level shift should not affect the displayed video image. Table 1. Function of Load-Detection Scheme AMPLIFIER OUTPUT Connected to External Load Not Connected to External Load MAX9511 RESISTANCE AT DAC INTERNAL OUTPUT SWITCH Open 37.5Ω Closed 75Ω _______________________________________________________________________________________ 9 Vertical and Horizontal SYNC Display Data Channel (DDC) The MAX9511 bidirectional display data channel (DDC) level translator allows for a lower voltage video controller logic to operate with a higher voltage external monitor logic. Power supplied at VDD2 defines the DDC input voltage thresholds while power supplied at VDD1 defines the DDC output thresholds. Two Schottky-clamped npn transistors shift the lower level DDC inputs to higher logic-level outputs. DDC_CLK_OUT and DDC_DATA_OUT are pulled to VDD1 by internal pullup resistors to prevent ambiguous conditions when left floating. At shutdown, DDC inputs can still respond to external commands. Slew-Rate Limiting The MAX9511 outputs are slew-rate limited to reduce EMI. Slew-rate limiting affects the large-signal bandwidth (LSBW) more than the small-signal bandwidth (SSBW), and can be scaled according to the following formula: LSBW(−3dB) = SR 2 × π × VOUT where VOUT is the output signal’s peak-to-peak voltage and LSBW(-3dB) is the -3dB bandwidth. The slew rate of the MAX9511 is controlled by a resistor between RX and AGND. The resistor (RRX) can be varied to optimize the EMI suppression to the display resolution while preserving the display quality. The RRX range is approximately 7kΩ for maximum slew rate and 50kΩ for minimum slew rate (see Figure 3). Slew-rate limiting can be approximated by: SLEW RATE vs. RRX 1600 MAX9511 fig03 The MAX9511 has separate, noninverting, vertical and horizontal sync buffers. Both sync inputs can level-shift an input as low as 2.3V to a 5V output. Both sync drivers have hysteresis at their input to prevent “chatter” in their outputs. The sync output drivers have a 55Ω (typ) output impedance (RSO) to match the cable impedance used for vertical and horizontal sync in most applications. Both sync inputs are pulled to DGND through a 47kΩ resistor if the controller’s SYNC source goes high impedance, or if the inputs are left floating, avoiding ambiguous output conditions. EMI can result from rapid transitions of the sync or the video signals. To reduce the rise and fall times of the sync signal, additional capacitance may be added to the sync outputs. Adding additional capacitance may require “recentering” the display. 1400 1200 SLEW RATE (V/µs) MAX9511 RGBHV Driver with EMI Suppression 1000 800 600 400 200 0 0 10 20 30 50 Figure 3. Slew Rate vs. RRX Shutdown The MAX9511 features a low-power shutdown mode for battery-powered/portable applications. Shutdown reduces the quiescent current of the video and sync drivers. Connecting SHDN to ground (DGND) disables the outputs and places the MAX9511 into a low-power shutdown mode. SHDN has a 330kΩ (typ) internal pulldown resistor to DGND. Connect SHDN to VDD2 for normal operation. Applications Information Customizing Slew Rates for Different Resolutions When the MAX9511 connects to devices of different resolutions, different slew rates should be used. The slew rate of the MAX9511 is adjustable by varying RRX between 7kΩ and 50kΩ. By selecting a valid RRX value for a resolution, the MAX9511 minimizes the EMI and optimizes the video output quality. Shown are two configurations to adjust slew rates using different RRX values for different video resolutions. Figure 4 shows how to customize slew rates for three resolutions. This circuit provides three predetermined slew rates by paralleling resistors to create three RRX values. The combination is controlled by a digital command from the video controller through a switch. This requires that the sample clock rates used by different resolutions are close. The sync bandwidth-limiting capacitors (CSYNC) are set for the highest resolution. ⎛ 7000 ⎞ SR = 1030 ⎜ ⎟ (V / µs) ⎝ RRX ⎠ 10 40 RRX (kΩ) ______________________________________________________________________________________ RGBHV Driver with EMI Suppression MAX9511 SYNC BANDWIDTH LIMITING CAPACITORS CSYNC = 47pF TO 470pF 5V CSYNC 0.1µF* POWERMANAGEMENT CIRCUIT 0.1µF REMOTE MONITOR 7 8 9 10 11 VDD2 DDC_DATA_OUT DDC_CLK_IN DDC_CLK_OUT H_SYNC_IN H_SYNC_OUT V_SYNC_IN DOCKING STATION VCC DDC_DATA_IN V_SYNC_OUT MAX9511 4 1 12 13 SHDN VDD1 VIDEO CONTROLLER CSYNC 2.3V TO 3.6V 5V GREEN_OUT 17 16 15 14 23 75Ω 75Ω RED_IN RED_OUT 21 75Ω 75Ω 37.5Ω BLUE_OUT 19 75Ω 75Ω 2 GREEN_IN 37.5Ω 5 BLUE_IN RX 6 37.5Ω R1 = 47kΩ AGND 3, 20, 22, 24 DGND COM2 NO1 COM1 NO2 18 R2 = 47kΩ *EXTRA BYPASS CAPACITORS *MAY BE REQUIRED. IN1 R3 = 18kΩ IN2 MAX4731 Figure 4. Three Resolution Slew-Rate Control Figure 4 showcases the setup for three commonly used resolutions: 1600 x 1200, 1280 x 1024, and 1024 x 768. Since the resolution change is relatively slow, the switch does not have to be fast. The impedance of the switch does not need to be low compared to RRX . When using a high-impedance switch, the resistance from the switch should be included to calculate RRX. The MAX4731 50Ω SPST analog switch shown in the figure is used with three external resistors to get RRX values of 10kΩ, 23.5kΩ, and 47kΩ for 1600 x 1200, 1280 x 1024, and 1024 x 768 resolutions, respectively. ______________________________________________________________________________________ 11 MAX9511 RGBHV Driver with EMI Suppression SYNC BANDWIDTH LIMITING CAPACITORS CSYNC = 47pF TO 470pF 5V CSYNC 0.1µF* POWERMANAGEMENT CIRCUIT 0.1µF REMOTE MONITOR 7 8 9 10 11 VDD2 DDC_DATA_OUT DDC_CLK_IN DDC_CLK_OUT H_SYNC_IN H_SYNC_OUT V_SYNC_IN DOCKING STATION VCC DDC_DATA_IN V_SYNC_OUT MAX9511 4 1 12 13 SHDN VDD1 VIDEO CONTROLLER CSYNC 2.3V TO 3.6V 5V GREEN_OUT 17 16 15 14 75Ω 23 75Ω RED_IN RED_OUT 75Ω 21 75Ω 37.5Ω BLUE_OUT 2 75Ω 19 75Ω GREEN_IN 37.5Ω 5 BLUE_IN RX 6 7kΩ H 37.5Ω AGND 3, 20, 22, 24 W DGND R1 = 100kΩ 18 SDA SCL *EXTRA BYPASS CAPACITORS *MAY BE REQUIRED. MAX5433 L Figure 5. Slew-Rate Control with a Digital Potentiometer The circuit in Figure 5 uses a MAX5433 digital potentiometer to provide more flexibility in customizing slew rates. An 100kΩ external trim resistor is placed in paral- 12 lel with the 100kΩ MAX5433 to limit the maximum value of RRX to 50kΩ. This setup provides 33 levels of RRX values through the I2C control ports at the MAX5433. ______________________________________________________________________________________ RGBHV Driver with EMI Suppression SYNC Bandwidth-Limiting Capacitors The output impedance, RSO, of the MAX9511 and an additional capacitance (CSYNC) can form a lowpass filter that reduces the jitter of the sync output signal. With RSO (55Ω typ) sync output impedance, the -3dB point of the lowpass filter is given by: f-3dB = 1 2πRSOCSYNC Power-Supply Bypassing and Ground Management The MAX9511’s high-frequency performance requires proper layout and bypassing. For best performance, place components as close to the device as possible. Digital or AC transient signals on AGND can create noise at the outputs. Return AGND to the lowest impedance ground available. Bypass the analog supply (VCC) with a 4.7µF capacitor paralleled with a 0.22µF and 0.001µF capacitor to AGND, placed as close to the device as possible. Bypass the digital supplies (VDD1, VDD2) with a 0.1µF capacitor to DGND, placed as close to the device as possible. Careful PC board ground layout minimizes crosstalk between the outputs. Choose CSYNC so f-3dB is well above the highest frequency of interest. Chip Information Pin Configuration TRANSISTOR COUNT: 353 PROCESS: BIPOLAR TOP VIEW VCC 1 24 AGND GREEN_IN 2 23 GREEN_OUT AGND 3 22 AGND RED_IN 4 BLUE_IN 5 21 RED_OUT MAX9511 RX 6 20 AGND 19 BLUE_OUT SHDN 7 18 DGND DDC_DATA_IN 8 17 DDC_DATA_OUT DDC_CLK_IN 9 16 DDC_CLK_OUT H_SYNC_IN 10 15 H_SYNC_OUT V_SYNC_IN 11 14 V_SYNC_OUT VDD2 12 13 VDD1 QSOP ______________________________________________________________________________________ 13 MAX9511 Power Supplies The MAX9511 operates with a 4.5V to 5.5V power supply for video (RGBHV), while DDC and SYNC operate from 2.3V to 3.6V and 4.5V to 5.5V supplies. RGBHV Driver with EMI Suppression MAX9511 Typical Operating Circuit SYNC BANDWIDTH LIMITING CAPACITORS CSYNC = 50pF TO 500pF 5V CSYNC 0.1µF* POWERMANAGEMENT CIRCUIT 0.1µF REMOTE MONITOR 7 12 13 SHDN VDD1 8 9 10 11 VIDEO CONTROLLER CSYNC 2.3V TO 3.6V 5V VDD2 DDC_DATA_OUT DDC_CLK_IN DDC_CLK_OUT H_SYNC_IN H_SYNC_OUT V_SYNC_IN DOCKING STATION VCC DDC_DATA_IN V_SYNC_OUT MAX9511 4 1 GREEN_OUT 17 16 15 14 75Ω 23 75Ω RED_IN RED_OUT 75Ω 21 75Ω 37.5Ω BLUE_OUT 75Ω 19 75Ω 2 GREEN_IN 37.5Ω 5 BLUE_IN RX 6 37.5Ω AGND 3, 20, 22, 24 14 DGND 18 RRX *EXTRA BYPASS CAPACITORS *MAY BE REQUIRED ______________________________________________________________________________________ RGBHV Driver with EMI Suppression QSOP.EPS PACKAGE OUTLINE, QSOP .150", .025" LEAD PITCH 21-0055 F 1 1 Revision History Pages changed at Rev 3: 1, 6, 13, 15 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15 © 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc. MAX9511 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages.)