ISL59481EVAL1Z Evaluation Board User’s Guide ® Application Note Introduction The ISL59481EVAL1Z evaluation board contains the ISL59481 Dual 4:1 RGB MUX amp and associated components needed to implement an 8:1 RGB+H/V sync video multiplexer. The 8 video input ports, and single output port are accessed using standard 15 pin VGA female connectors. The I/O connectors are compatible with most VGA, SVGA and XGA video sources and video monitors with VGA cable interfaces. A typical application would use the ISL5948XEVAL1Z board to multiplex anywhere from 2 to 8 PC’s or laptops to a single video monitor or projector. Evaluation Board Description and Key Features The multiplexing of the RGB video is performed by the ISL59481. Multiplexing the H and V sync signals is accomplished using two ISL84051 8:1 analog switches. The ISL59481 Video MUX and the analog H and V sync multiplexers have the same input channel select logic coding, and are parallel-connected to form a single 3 input binary coded interface (S0, S1, S2). An additional ISL84051 8:1 analog switch and channel-select LED indicators are included to identify the selected input channel. The evaluation board contains three different channel select options via jumpers on the board. Switches on the board enable direct logic control in binary format. The on-board oscillator and 4-bit counter can be connected to provide a May 3, 2007 AN1320.0 continuous channel-by-channel scan of as few as 2 input channels and as many as 8 input channels (Table 2). A jumper option allows the user to disconnect the auto-scan oscillator and use the on-board momentary-contact switch to manually scan through the selected channels. Reference Documents • Data Sheet FN6394 “Dual, 500MHz Triple, Multiplexing Amplifiers” Getting Started The evaluation board should have the same appearance as the silk screen shown in Figure 1. Prior to applying power, connect the source input VGA cables and the evaluation board output VGA cable to the respective video components. The evaluation board, as supplied, is designed for 75Ω source impedances and requires a 75Ω termination impedance in the output display device. Applying Power to the Evaluation Board The following safeguards will ensure correct power-up. 1. Limit the current on ±5V supplies to 250mA. 2. Turn on the power supplies after the power cables are attached to the evaluation board. Power supply protection Schottky diodes are included on the ±5V supplies to prevent damage due to reverse polarity. Evaluation Board Jumper, Cable Header, and Switch Descriptions COMPONENT DESCRIPTION JUMPERS J1 Selects channel select via single-step momentary contact switch S4, or auto mode using on-board oscillator J-S0 Selects S0 logic input to manual control via switch S0 or through external control ribbon cable header J-S1 Selects S1 logic input to manual control via switch S1 or through external control ribbon cable header J-S2 Selects S2 logic input to manual control via switch S2 or through external control ribbon cable header HEADERS EN External MUX enable: Internal pull-down (logic 0) enables RGB+H/V output, logic high disables RGB and H/V sync output S0 External S0 channel select logic input S1 External S1 channel select logic input S2 External S2 channel select logic input SWITCHES S0 Manual channel select logic input S0 S1 Manual channel select logic input S1 S2 Manual channel select logic input S2 S3 Momentary contact channel select step control 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2007. All Rights Reserved All other trademarks mentioned are the property of their respective owners. Application Note 1320 FIGURE 1. ISL5948xEVAL1Z TOP VIEW 2 AN1320.0 May 3, 2007 Application Note 1320 Testing the Evaluation Board Testing the video and sync signal paths is accomplished using 1 or more RGB+H/V test video sources and a video monitor as the measurement device. Before powering the board, connect the jumpers as follows: 1. Connect jumpers J-S0, J-S1 and J-S2 to the MANUAL position (center to right post). 2. Connect jumper J1 to the single-step position (center to left post). The following tests should be performed in the order shown. AUTO-SCAN TEST 1. Connect scope probe to the J1 AUTO pin and observe a logic level (0V to +5V) square wave with ~3s period. 2. Connect jumpers J-S0, J-S1, and J-S2 to the AUTO position (center to left post). 3. Connect jumper J1 to the AUTO position and observe that the display scans all the test sources connected to the input channels (center to right post). 4. Connect jumper J1 to the single-step position and use the momentary contact switch S4 to manually test all the sources. Test completed. Power Supply Tests 1. Connect an ammeter in series with the +5V and -5V supply. RGB Video Signal Path 2. Connect power supplies to the respective +5V, -5V and ground banana jacks. The video inputs are terminated with 75Ω resulting in an overall RGB video path gain of 1 when using 75Ω video source impedance and load terminations (Figure 2). The RGB outputs contain series-connected 75Ω back-termination resistors for cable driving. The ISL59481 operates with a gain of +1. Provision for additional gain is provided by triple op amp U6 (EL5364), gain resistors R62, R63, R67, and R71 thru R73. The 0Ω resistors R68, thru R70 must be removed when using the triple op amp. Gain reduction is best achieved using the divider network Rs and Rt. Capacitor pads (Cnp) are provided to adjust the frequency response of the amplifier. 3. Set supplies to +5V; ±50mV and -5V; ±50mV. Supply power to the board. 4. Measure +5V supply current = +110mA ±20mA 5. Measure -5V supply current = -100mA ±20mA CHANNEL SELECT LOGIC AND VIDEO PERFORMANCE TEST 1. Calibrate the video test source with the video monitor by connecting the source(s) to the video monitor and selecting a display suitable for verifying correct luminance, display resolution and H/V sync lock. The test display in the following evaluation board tests should be identical to the test display. 2. Re-connect the video monitor to the VIDEO_OUT VGA connector on the evaluation board. 3. Connect the video test source to IN0. Additional video sources can speed up the verification process. If more than 1 test source is available connect each in sequential fashion to IN1, IN2 etc. 4. Set switches S0, S1 and S2 to the GND position and apply power. ISL59481 IN0 TO IN3 RS, 75Ω +1 HIZ 75Ω 1/3 EL5364 CHANNEL Cnp* SELECT IN4 TO IN7 75Ω HIZ +1 Rt 499Ω Rg 432Ω + - VOUT V 75Ω Rf 562Ω RS, 75Ω 5. After ~3s the test display supplied to IN0 should appear on the test monitor exactly as it appeared in step 1. NOTE: The ~3s delay is a built in delay common in many display devices to lock onto the H/V sync signals and adjust the picture prior to enabling the display screen. 6. Perform the display test on the remaining video inputs by moving the video input source to the appropriate input according to the truth table in Table 1. 7. Signal calibration can also be performed using the RGB BNC connectors J6, J7 and J8 to connect an external signal into IN7 input, while monitoring the RGB outputs using BNCs J3, J4 and J5. To connect the BNCs, the open resistor placements R76 through R81 must be populated with 0Ω resistors. 3 * Cnp IS NOT POPULATED AND IS PROVIDED FOR FREQUENCY RESPONSE ADJUSTMENT FIGURE 2. VIDEO SIGNAL PATH Channel Select Logic The ISL59481 RGB MUX and the H/V sync MUX share the same 1 of 8 input channel select logic inputs (S0, S1, S2). The channel select logic is shown in Table 1. Three methods of channel select logic control are provided using jumpers. AN1320.0 May 3, 2007 Application Note 1320 TABLE 1. CHANNEL SELECT TRUTH TABLE S2 S1 S0 VIDEO OUT 0 0 0 IN0 0 0 1 IN1 0 1 0 IN2 0 1 1 IN3 1 0 0 IN4 1 0 1 IN5 1 1 0 IN6 1 1 1 IN7 Auto Sequencing Using the On-Board Oscillator An on-board 0.3Hz R-C oscillator (Figure 3) drives the master clock of the 4-bit binary counter, which generates the channel select logic inputs S0, S1 and S2. The default 6s channel scan rate provides the time needed by the display to sync-lock and adjust the picture prior to enabling the display. The 2.2MΩ (R1) resistor value can be reduced to speed up the channel scan time. Jumper J1 is provided to select either the 6s auto-step timer, or the momentary contact switch for manual stepping. J1 SINGLESTEP AUTOSTEP S4 MOMENTARY CONTACT SWITCH Internal and External Channel Select Logic J-S0, J-S1 and J-S2 are two-position jumpers that control the method of channel selection. In the AUTO position, the internal channel scan is enabled. The MANUAL position connects the on-board SPDT switches (S0, S1, and S2) for manual selection. A parallel-connected EXTERNAL CONTROL ribbon cable header is provided for external channel select control. A wide range of auto-scan options can be selected by connecting only 1 or 2 of the 3 jumpers to the internal logic, with the remainder connected to the switch. For example, connecting jumper J-S0 to the AUTO position and connecting jumpers J-S1 and J-S2 to the MANUAL position with the switches S1 and S2 to the logic 0 state limits the channel scan to only 2 of the 8 channels (IN0 and IN1). Moving a second jumper from the MANUAL position to the AUTO position, increases the number of channels scanned from 2 to 4. The complete list of channel scan jumper options are shown in Table 2. TO BINARY COUNTER CLK R1 2.2M 5 6 U4C C1 4.7µF FIGURE 3. CHANNEL SCAN OSCILLATOR 4 AN1320.0 May 3, 2007 Application Note 1320 TABLE 2. CHANNEL SCAN SELECT LOGIC TABLE JUMPER POSITION SWITCH POSITION CHANNELS SELECTED CHANNELS SCANNED J-S2 J-S1 J-S0 S2 S1 S0 IN0 IN1 IN2 IN3 IN4 IN5 IN6 IN7 8 Auto Auto Auto - - - X X X X X X X X 4 Manual Auto Auto 0 - - X X X X Manual Auto Auto 1 - - X X X X Auto Manual Auto - 0 - X X Auto Manual Auto - 1 - X X Auto Auto Manual - - 0 Auto Auto Manual - - 1 Manual Manual Auto 0 0 - Manual Manual Auto 0 1 - Manual Manual Auto 1 0 - Manual Manual Auto 1 1 - 2 Auto Manual Manual - 0 0 Auto Manual Manual - 0 1 Auto Manual Manual - 1 0 Auto Manual Manual - 1 1 Manual Auto Manual 0 - 0 Manual Auto Manual 0 - 1 Manual Auto Manual 1 - 0 Manual Auto Manual 1 - 1 5 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X AN1320.0 May 3, 2007 Application Note 1320 ISL59481EVAL1Z Schematic Diagram 499 499 499 562 432 432 562 562 432 1 6 AN1320.0 May 3, 2007 Application Note 1320 ISL5948xEVAL1Z Components List COMPONENT P/N, VALUE MANUFACTURER RATING PWB ISL5948xEVAL1Z REV A PCB, ROHS Intersil Corp. N/A U1 - 8:1 RGB Video MUX ISL59481IRZA QFN48 Pb-Free Intersil Corp. N/A U2, U3, U7 - 8:1 Analog MUX ISL84051IBZ SOIC16 Pb-Free Intersil Corp. N/A U4 - Hex Inverter SN74HC14D SOIC14 TI N/A U5 - 4-Bit Binary Counter SN74HC161D SOIC16 TI N/A U6 - Triple 600MHz Op Amp EL5364ISZ SOIC16 Pb-Free Intersil Corp. N/A C4, C7 CAP, SMD, 0603 1000pF 10%, X7R 25V C2, C5, C8 to C13, C21, C23, C25 CAPACITOR, SMD, 0603, 0.1µF N/A 25V C3, C6 CAPACITOR, SMD, 0805, 10µF 10%, X5R 6.3V C1 CAPACITOR, SMD, 0805, 4.7µF 10%, X5R 16V C14, C17 to C20 CAPACITOR, SMD, 0805, DNP N/A DNP IN0 TO IN7, VIDEO_OUT 181-015-213R171 CONN-SUB MINI D, 15 PIN, RECEPTACLE, RT ANGLE, FRONT METAL SHELL NORCOMP N/A +5V, -5V, EN, GND CONN-JACK, BANA-SS-SDRLESS, VERTIC N/A N/A J2 CONN-HEADER, 4 PIN, BRKAWY, 2.54mm, VERT J2 J-S0, J-S1, J-S2, J1 CONN-HEADER, 1x3, BRKAWY 1x36, 0.1 N/A D1, D2 MBR0540T1-T DIODE-RECTIFIER, SMD SOD-123, 2 PIN SEMICON 40V, 0.5A LED0 to LED7 597-3111-407F LED, SMD,1206, RED, 30mA, 60mW,17mcd, ROHS DIALIGHT N/A R68 to R70, R76 to R81 RESISTOR, SMD, 0603, 0Ω, DNP R3 to R5, R55 to 58 RESISTOR, SMD, 0805, DNP, TF N/A DNP R82 to R87 RESISTOR, SMD, 0603, 0Ω N/A N/A R62, R67, R73 RESISTOR, SMD, 0603, 432Ω 1% 1/10W R63, R71, R72 RESISTOR, SMD, 0603, 562Ω 1% 1/10W R6 to R9, R10 to R12, R13 to R16, R21 to RESISTOR, SMD, 0805, 75Ω R29, R32 to R35, R39, R43 to R49 1% 1/10W R13 to R15, R17 to R20, R33, R34, R39, RESISTOR, SMD, 0805, 0Ω N/A 1/10W R42, R50 RESISTOR, SMD, 0805, 10k 5% 1/10W R74 RESISTOR, SMD, 0805, 20kΩ, 5% 1/10W R1 RESISTOR, SMD, 0805, 2.2M 5% 1/8W R2, R30, R31, R36, R37, R40, R41 RESISTOR, SMD, 0805, 4.7k 5% 1/10W R59 to R61 RESISTOR, DNP, SMD, 0805, 499, DNP 5% DNP R75 RESISTOR, SMD, 0603, 1kΩ 5% 1/10W S0 to S2 SWITCH-TOGGLE, THRU, SPDT, 5P, ON-N N/A N/A S3 SWITCH-PUSHBUTTON, TH, 6mm, 4P, ON/OFF, N/A 12V, 0.05A N/A DNP Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that the Application Note or Technical Brief is current before proceeding. For information regarding Intersil Corporation and its products, see www.intersil.com 7 AN1320.0 May 3, 2007