19-0219; Rev 2; 6/94 AL ANU IT M HEET K N S TIO TA LUA S DA EVA LLOW FO Two-Channel, Triple/Quad RGB Video Switches and Buffers ____________________________Features ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ 100MHz Unity-Gain Bandwidth 90MHz Bandwidth with 2V/V Gain 0.01%/0.03° Differential Gain/Phase Error Drives 50Ω and 75Ω Back-Terminated Cable Directly Wide Output Swing: ±2V into 75Ω ±2.5V into 150Ω 300V/µs Slew Rate (2V/V gain) 20ns Channel Switching Time Logic Disable Mode: High-Z Outputs Reduced Power Consumption Outputs May Be Paralleled for Larger Networks 5pF Input Capacitance (channel on or off) ______________Ordering Information TEMP. RANGE PIN-PACKAGE MAX463CNG PART 0°C to +70°C 24 Narrow Plastic DIP MAX463CWG MAX463C/D MAX463ENG MAX463EWG 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 24 Wide SO Dice* 24 Narrow Plastic DIP 24 Wide SO PART DESCRIPTION VOLTAGE GAIN (V/V) MAX463 Triple RGB Switch & Buffer 1 MAX464 Quad RGB Switch & Buffer 1 MAX465 Triple RGB Switch & Buffer 2 MAX466 Quad RGB Switch & Buffer 2 MAX467 Triple Video Buffer 1 MAX468 Quad Video Buffer 1 IN0A 1 2 GND 2 2 IN1A 3 GND 4 IN2A 5 V- 6 V- 7 RGB Multiplexing IN0B 8 RGB Color Video Overlay Editors GND 9 RGB Color Video Security Systems IN1B 10 15 GND RGB Medical Imaging GND 11 14 V+ Coaxial-Cable Line Drivers IN2B 12 13 OUT2 Quad Video Buffer ________________________Applications Broadcast-Quality Color-Signal Multiplexing TOP VIEW 24 GND MAX463 MAX465 23 LE 22 EN 21 A0 SWITCH MAX470 Triple Video Buffer _________________Pin Configurations 20 CS 3P2T MAX469 Ordering Information continued on last page. * Dice are specified at TA = +25°C, DC parameters only. 18 OUT0 19 V- 17 V+ 16 OUT1 DIP/SO Typical Operating Circuit appears at end of data sheet. Pin Configurations continued at end of data sheet. ________________________________________________________________ Maxim Integrated Products Call toll free 1-800-998-8800 for free samples or literature. 1 MAX463–MAX470 _______________General Description The MAX463–MAX470 series of two-channel, triple/quad buffered video switches and video buffers combines high-accuracy, unity-gain-stable amplifiers with high-performance video switches. Fast switching time and low differential gain and phase error make this series of switches and buffers ideal for all video applications. The devices are all specified for ±5V supply operation with inputs and outputs as high as ±2.5V when driving 150Ω loads (75Ω back-terminated cable). Input capacitance is typically only 5pF, and channel-tochannel crosstalk is better than 60dB, accomplished by surrounding all inputs with AC ground pins. The onboard amplifiers feature a 200V/µs slew rate (300V/µs for AV = 2V/V amplifiers), and a bandwidth of 100MHz (90MHz for AV = 2V/V buffers). Channel selection is controlled by a single TTL-compatible input pin or by a microprocessor interface, and channel switch time is only 20ns. For design flexibility, devices are offered with bufferamplifier gains of 1V/V or 2V/V for 75Ω back-terminated applications. Output amplifiers have a guaranteed output swing of ±2V into 75Ω. Devices offered in this series are as follows: MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers ABSOLUTE MAXIMUM RATINGS Power-Supply Ranges V+ to V- ................................................................................12V Analog Input Voltage ..........................(V- - 0.3V) to (V+ + 0.3V) Digital Input Voltage ...................................-0.3V to (V+ + 0.3V) Output Short-Circuit Duration (to GND)........................1 Minute Input Current into Any Pin, Power On or Off...................±50mA Continuous Power Dissipation (TA = +70°C) 16-Pin Plastic DIP (derate 22.22mW/°C above +70°C) ....1778mW 16-Pin Wide SO (derate 20.00mW/°C above +70°C) .......1600mW 24-Pin Narrow Plastic DIP (derate 20.2mW/°C above +70°C)..................................1620mW 24-Pin Wide SO (derate 19.3mW/°C above +70°C) .........1590mW 28-Pin Narrow Plastic DIP (derate 20.2mW/°C above +70°C)..................................1620mW 28-Pin Wide SO (derate 18.1mW/°C above +70°C) .........1440mW Operating Temperature Ranges MAX4_ _C_ _.........................................................0°C to +70°C MAX4_ _E_ _ ......................................................-40°C to +85°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+300°C 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 (V+ = 5V, V- = -5V, -2V ≤ VIN ≤ +2V, RLOAD = 75Ω, unless otherwise noted.) PARAMETER SYMBOL Operating Supply Voltage VS Input Voltage Range VIN Offset Voltage VOS Power-Supply Rejection Ratio PSRR On Input Bias Current IBIAS On Input Resistance RIN Input Capacitance CIN Voltage-Gain Accuracy Output Voltage Swing VOUT CONDITIONS TA = +25°C MIN TYP MAX ±4.75 ±5 -2 ±3 50 300 Channel off or on ROUT ROUTD Output Capacitance, Disabled Mode COUTD Positive Supply Current 2 I+ ±5.25 -2 2 V ±15 mV ±10 50 ±3 700 150 µA kΩ pF 0.2 0.5 1.0 MAX465/MAX466, MAX469/MAX470, RLOAD = 150Ω, (Note 2) 0.3 1.0 2.0 % RLOAD = 150Ω ±2.5 ±2.8 ±2.5 RLOAD = 75Ω ±2.0 ±2.4 -1.5/+2 fIN = DC V dB ±5 5 V 5 MAX463/MAX464, MAX467/MAX468 0.05 MAX465/MAX466, MAX469/MAX470 Output Resistance, Disabled Mode ±4.75 2 MAX463/MAX464, MAX467/MAX468 (Note 1) fIN = 10MHz Output Impedance UNITS ±5.25 60 ±1 TA = TMIN to TMAX MIN MAX Ω 0.1 MAX463/MAX464 150 250 100 kΩ MAX465/MAX466 0.7 1 0.7 kΩ MAX463–MAX466 MAX463/MAX465/MAX467/MAX469, VIN = 0V MAX464/MAX466/MAX468/MAX470, VIN = 0V 10 pF 65 80 100 85 100 120 MAX463/MAX465, disabled mode 35 45 50 MAX464/MAX466, disabled mode 40 50 55 _______________________________________________________________________________________ mA Two-Channel, Triple/Quad RGB Video Switches and Buffers (V+ = 5V, V- = -5V, -2V ≤ VIN ≤ +2V, RLOAD = 75Ω, unless otherwise noted.) PARAMETER Negative Supply Current SYMBOL I- Input Noise Density en Slew Rate SR -3dB Bandwidth BW Differential Gain Error (Note 3) DG Differential Phase Error (Note 3) DP Settling Time to 0.1% tS CONDITIONS TA = +25°C MIN TYP MAX TA = TMIN to TMAX UNITS MIN MAX MAX463/MAX465/MAX467/MAX469, VIN = 0V 50 65 75 MAX464/MAX466/MAX468/MAX470, VIN = 0V 65 80 95 MAX463/MAX465, disabled mode 20 30 35 MAX464/MAX466, disabled mode 25 35 40 fIN = 10kHz 20 MAX463/MAX464, MAX467/MAX468 200 MAX465/MAX466, MAX469/MAX470 300 MAX463/MAX464, MAX467/MAX468 100 MAX465/MAX466, MAX469/MAX470 90 MAX463/MAX464, MAX467/MAX468 0.01 MAX465/MAX466, MAX469/MAX470 0.12 MAX463/MAX464, MAX467/MAX468 0.03 MAX465/MAX466, MAX469/MAX470 0.14 mA –— nV/√Hz V/µs MHz % deg. VIN = 2V-to-0V step 50 ns XTALK fIN = 10MHz 60 dB All-Hostile Crosstalk (Note 5) XTALK fIN = 10MHz 50 dB All-Hostile Off Isolation (Note 6) ISO fIN = 10MHz, MAX463–MAX466 70 dB tPD MAX463–MAX466 15 ns tSW MAX463–MAX466 20 ns VINA = VINB = 0V, MAX463–MAX466 300 mVP-P tOFF MAX463–MAX466 80 ns tON MAX463–MAX466 100 ns Adjacent Channel Crosstalk (Note 4) Channel Switching Propagation Delay (Note 7) Channel Switching Time (Note 8) Switching Transient Amplifier Switching Off-Time (Note 9) Amplifier Switching On-Time (Note 10) Logic Input High Threshold VIH Logic Input Low Threshold VIL Logic Input Current High IINHI Logic Input Current Low IINLO —– —– EN, A0, CS, LE; MAX463–MAX466 —– —– EN, A0, CS, LE; MAX463–MAX466 —– —– EN, A0, CS, LE; MAX463–MAX466 —– —– EN, A0, CS, LE; MAX463–MAX466 2 2 V 200 200 µA 200 200 µA 0.8 0.8 V _______________________________________________________________________________________ 3 MAX463–MAX470 ELECTRICAL CHARACTERISTICS (continued) ELECTRICAL CHARACTERISTICS (continued) (V+ = 5V, V- = -5V, -2V ≤ VIN ≤ +2V, RLOAD = 75Ω, unless otherwise noted.) PARAMETER SYMBOL Address Setup Time (Note 11) tSU Address Hold Time (Note 11) —– CS Pulse Width Low (Note 11) tH Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Note 10: Note 11: TA = +25°C MIN TYP MAX CONDITIONS —– —– EN, A0, CS, LE; MAX463–MAX466 —– —– EN, A0, CS, LE; MAX463–MAX466 —– —– EN, A0, CS, LE; MAX463–MAX466 tCS TA = TMIN to TMAX UNITS MIN MAX 30 30 0 ns 0 15 ns 15 ns Voltage gain accuracy for the unity-gain devices is defined as [(VOUT - VIN) at VIN = 1V - (VOUT - VIN) at VIN = -1V]/2. Voltage gain accuracy for the gain-of-two devices is defined as [(VOUT/2 - VIN) at VIN = 1V - (VOUT/2 - VIN) at VIN = -1V]/2. Tested with a 3.58MHz sine wave of amplitude 40IRE superimposed on a linear ramp (0IRE to 100IRE), RL = 150Ω to ground. Tested with the selected input connected to ground through a 75Ω resistor, and a 4VP-P sine wave at 10MHz driving adjacent input. Tested in the same manner as described in Note 4, but with all other inputs driven. —– Tested with LE = 0V, EN = V+, and all inputs driven with a 4VP-P, 10MHz sine wave. Measured from a channel switch command to measurable activity at the output. Measured from where the output begins to move to the point where it is well defined. Measured from a disable command to amplifier in a non-driving state. Measured from an enable command to the point where the output reaches 90% current out. Guaranteed by design. __________________________________________Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) 0 PHASE –1 36 72 108 –2 144 –3 10k 180 100k 1M FREQUENCY (Hz) 4 10M 100M PHASE (DEGREES) 0 MAX463/470 -03 50 10 V– PSRR (dB) GAIN OUTPUT IMPEDANCE (Ω) 1 60 MAX463/470 -02 100 MAX463/470 -01 2 MAX468 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX464 OUTPUT IMPEDANCE vs. FREQUENCY MAX468 GAIN AND PHASE RESPONSES GAIN (dB) MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers 1 0.1 40 V+ 30 20 0.01 10 10k 100k 1M 10M FREQUENCY (Hz) 100M 1G 1k 10k 100k 1M FREQUENCY (Hz) _______________________________________________________________________________________ 10M 100M Two-Channel, Triple/Quad RGB Video Switches and Buffers MAX463 DISABLED OUTPUT RESISTANCE vs. TEMPERATURE 0.12 0.10 MAX463 0.08 MAX463/470 -05 OUTPUT RESISTANCE (kΩ) MAX465 350 300 250 200 0.06 –25 0 25 50 75 –25 0 I+ 20 15 I– 10 –50 75 100 25 50 75 100 4 MAX463/470 -07 20 I– 10 0 OUTPUT VOLTAGE SWING vs. LOAD RESISTANCE 25 0 –25 TEMPERATURE (°C) 30 15 50 100 I+ 5 25 75 35 SUPPLY CURRENT (mA) 25 0 50 40 MAX463/470 -09 30 TEMPERATURE (°C) 25 DISABLED SUPPLY CURRENT vs. TEMPERATURE SUPPLY CURRENT PER AMPLIFIER vs. TEMPERATURE –25 1.15 TEMPERATURE (°C) TEMPERATURE (°C) –50 1.20 1.10 –50 100 1.25 MAX463/470 -08 –50 SUPPLY CURRENT PER AMPLIFIER (mA) 1.30 3 OUTPUT VOLTAGE (V) PERCENTAGE (%) 0.14 400 OUTPUT RESISTANCE (kΩ) MAX463/470 -04 0.16 MAX465 DISABLED OUTPUT RESISTANCE vs. TEMPERATURE MAX463/470 -06 VOLTAGE GAIN ACCURACY vs. TEMPERATURE 2 1 MAX463/4/7/8:VIN = 4V MAX465/6/9/70:VIN = 2V 0 –1 –2 –3 –4 –50 –25 0 25 50 TEMPERATURE (°C) 75 100 10 100 1000 10000 LOAD RESISTANCE ( Ω ) _______________________________________________________________________________________ 5 MAX463–MAX470 ____________________________Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers ____________________________Typical Operating Characteristics (continued) (TA = +25°C, unless otherwise noted.) MAX464 SMALL-SIGNAL STEP RESPONSE MAX466 SMALL-SIGNAL STEP RESPONSE GND A: VIN, 100mV/div GND A: VIN, 100mV/div GND B: VOUT, 100mV/div GND B: VOUT, 200mV/div 10ns/div 10ns/div MAX464 LARGE-SIGNAL STEP RESPONSE MAX466 LARGE-SIGNAL STEP RESPONSE GND GND A: VIN, 1V/div A: VIN, 2V/div GND GND B: VOUT, 2V/div B: VOUT, 2V/div 20ns/div 20ns/div MAX464 OUTPUT TRANSIENT WHEN SWITCHING BETWEEN TWO GROUNDED INPUTS MAX464 EN RESPONSE TIME A: CS, 5V/div GND B: A0, 5V/div GND GND C: OUT0, 100mV/div 50ns/div 6 A: CS, 5V/div GND GND B: EN, 5V/div GND C: OUT3, 1V/div tOFF tON _______________________________________________________________________________________ 50ns/div Two-Channel, Triple/Quad RGB Video Switches and Buffers PIN MAX463/MAX465 MAX464/MAX466 NAME FUNCTION 1 28 IN0A Channel A, Analog Input 0 2, 4, 9, 11, 15, 24 1, 3, 5, 11, 13, 19 GND Analog Ground 3 2 IN1A Channel A, Analog Input 1 5 4 IN2A Channel A, Analog Input 2 – 6 IN3A Channel A, Analog Input 3 6, 7, 19 7, 9, 21, 23 V- 8 8 IN0B Channel B, Analog Input 0 10 10 IN1B Channel B, Analog Input 1 12 12 IN2B Channel B, Analog Input 2 – 14 IN3B Channel B, Analog Input 3 – 15 OUT3 Buffered Analog Output 3 13 17 OUT2 Buffered Analog Output 2 14, 17 16, 18 V+ 16 20 OUT1 Buffered Analog Output 1 18 22 OUT0 Buffered Analog Output 0 20 24 –—– CS 21 25 A0 22 26 –—– EN 23 27 LE PIN MAX467/MAX469 MAX468/MAX470 Negative Power-Supply Input. Connect to -5V. Thermal path. Positive Power-Supply Input. Connect to +5V. –—– —– Chip-Select—latch control for the digital inputs. When CS is low, A0 and EN —– input registers are transparent. When CS goes high, the A0 input register latches. —– —– If LE is high, the EN input register also latches when CS goes high (see LE). —– Channel-Select Input. When CS is low, driving A0 low selects channel A and driving A0 high selects channel B. —– —– Buffer-Enable Input. When CS is low or LE is low, driving EN low enables —– all output buffers and driving EN high disables all output buffers. —– Digital Latch-Enable Input. When LE is low, the EN register is transparent; —– —– when LE is high, the EN register is transparent only when CS is low. Hardwire to V+ or GND for best crosstalk performance. NAME FUNCTION 1 1 IN0 Analog Input 0 2, 7, 8, 9, 15 2, 7, 15 GND Analog Ground 3 3 IN1 Analog Input 1 4, 5, 12, 13 4, 5, 12, 13 V- 6 6 IN2 Analog Input 2 – 8 IN3 Analog Input 3 – 9 OUT3 10 10 V+ 11 11 OUT2 Buffered Analog Output 2 14 14 OUT1 Buffered Analog Output 1 16 16 OUT0 Buffered Analog Output 0 Negative Power-Supply Input. Connect to -5V. Thermal path. Buffered Analog Output 3 Positive Power-Supply Input. Connect to +5V. _______________________________________________________________________________________ 7 MAX463–MAX470 _____________________________________________________________Pin Descriptions _______________Detailed Description The MAX463–MAX470 have a bipolar construction, which results in a typical channel input capacitance of only 5pF, whether the channel is on or off. This low input capacitance allows the amplifiers to realize full AC performance, even with source impedances as great as 250Ω. It also minimizes switching transients because the driving source sees the same load whether the channel is on or off. Low input capacitance is critical, because it forms a single-pole RC lowpass filter with the output impedance of the signal source, and this filter can limit the system’s signal bandwidth if the RC product becomes too large. The MAX465/MAX466/MAX469/MAX470’s amplifiers are internally configured for a gain of two, resulting in an overall gain of one at the cable output when driving back-terminated coaxial cable (see the section Driving Coaxial Cable). The MAX463/MAX464/MAX467/MAX468 are internally configured for unity gain. Power-Supply Bypassing and Board Layout To realize the full AC performance of high-speed amplifiers, pay careful attention to power-supply bypassing and board layout, and use a large, low-impedance ground plane. With multi-layer boards, the ground plane should be located on the layer that is not dedicated to a specific signal trace. To prevent unwanted signal coupling, minimize the trace area at the circuit's critical high-impedance nodes, and surround the analog inputs with an AC ground trace (analog ground, bypassed DC power supply, etc). The analog input pins to the MAX463–MAX470 have been separated with AC ground pins (GND, V+, V-, or a hard-wired logic input) to minimize parasitic coupling, which can degrade crosstalk and/or stability of the amplifier. Keep signal paths as short as possible to minimize inductance, and ensure that all input channel traces are of equal length to maintain the phase relationship between the R, G, and B signals. Connect the coaxial-cable shield to the ground side of the 75Ω terminating resistor at the ground plane to further reduce crosstalk (see Figure 1). Bypass all power-supply pins directly to the ground plane with 0.1µF ceramic capacitors, placed as close to the supply pins as possible. For high-current loads, it may be necessary to include 10µF tantalum or aluminum-electrolytic capacitors in parallel with the 0.1µF ceramics. Keep capacitor lead lengths as short as possible to minimize series inductance; surface-mount (chip) capacitors are ideal. 8 COAX RT RETURN CURRENT COAX RT GROUND PLANE MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers RETURN CURRENT Figure 1. Low-Crosstalk Layout. Return current from the termination resistor does not flow through the ground plane. Connect all V- pins to a large power plane. The V- pins conduct heat away from the internal die, aiding thermal dissipation. Differential Gain and Phase Errors Differential gain and phase errors are critical specifications for an amplifier/buffer in color video applications, because these errors correspond directly to changes in the color of the displayed picture in composite video systems. The MAX467–MAX470 have low differential gain and phase errors, making them ideal in broadcastquality composite color applications, as well as in RGB video systems where these errors are less significant. The MAX467–MAX470 differential gain and phase errors are measured with the Tektronix VM700 Video Measurement Set, with the input test signal provided by the Tektronix 1910 Digital Generator as shown in Figure 2. Measuring the differential gain and phase of the MAX469/MAX470 (Figure 2a) is straightforward because the output amplifiers are configured for a gain of two, allowing connection to the VM700 through a back-terminated coaxial cable. Since the MAX467/MAX468 are unity-gain devices, driving a back-terminated coax would result in a gain of 1/2 at the VM700. Figure 2b shows a test method to measure the differential gain and phase for the MAX467/MAX468. First, measure and store the video signal with the device under test (DUT) removed and replaced with a short circuit, and the 150Ω load resistor omitted. Then do another measurement with the DUT and load resistor in the circuit, and calculate the differential gain and phase errors by subtracting the results. _______________________________________________________________________________________ Two-Channel, Triple/Quad RGB Video Switches and Buffers MAX463–MAX470 75Ω CABLE (a) 75Ω 75Ω MAX469/MAX470 75Ω CABLE 75Ω CABLE DUT 75Ω SOURCE: TEKTRONIX 1910 DIGITAL GENERATOR (b) 75Ω MEASUREMENT: TEKTRONIX VM700 VIDEO MEASUREMENT SET MAX467/MAX468 75Ω 75Ω CABLE 75Ω 75Ω CABLE AV = 2 DUT 75Ω 150Ω Figure 2. Differential Phase and Gain Error Test Circuits (a) for the MAX469/MAX470 Gain-of-Two Amplifiers, (b) for the MAX467/MAX468 Unity-Gain Amplifiers Driving Coaxial Cable High-speed performance, excellent output current capability, and an internally fixed gain of two make the MAX465/MAX466/MAX469/MAX470 ideal for driving 50Ω or 75Ω back-terminated coaxial cables. The MAX465/MAX466/MAX469/MAX470 will drive a 150Ω load (75Ω back-terminated cable) to ±2.5V. The Typical Operating Circuit shows the MAX465/MAX466 driving four back-terminated 75Ω video cables. The back-termination resistor (at each amplifier output) provides impedance matching at the driven end of the cable to eliminate signal reflections. It forms a voltage divider with the load impedance, which attenuates the signal at the cable output by one-half. The amplifier operates with an internal 2V/V closed-loop gain to provide unity gain at the cable’s output. The MAX463–MAX470 phase margin and capacitiveload driving performance are optimized by internal compensation. When driving capacitive loads greater than 50pF, connect an isolation resistor between the amplifier output and the capacitive load, as shown in Figure 3. AV = 1 12Ω IN_ OUT_ 100pF Driving Capacitive Loads Driving large capacitive loads increases the likelihood of oscillation in most amplifier circuits. This is especially true for circuits with high loop-gains, like voltage followers. The amplifier’s output impedance and the capacitive load form an RC filter that adds a pole to the loop response. If the pole frequency is low enough, as when driving a large capacitive load, the circuit phase margin is degraded and oscillation may occur. MAX468 Figure 3a. Using an Isolation Resistor with a Capacitive Load _______________________________________________________________________________________ 9 MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers MAX468 (WITH ISOLATION RESISTOR) MAX468 (NO ISOLATION RESISTOR) A A GND GND B GND 1µs/div CLOAD = 100pF, RISOLATION = 12Ω 1µs/div CLOAD = 100pF B GND A: VIN, 500mV/div A: VIN, 500mV/div B: VOUT, 500mV/div B: VOUT, 500mV/div Figure 3b. Step Response without an Isolation Resistor Figure 3c. Step Response with an Isolation Resistor Digital Interface disabled MAX463/MAX464 outputs exhibit a 250kΩ typical resistance. Because their internal feedback resistors are required to produce a gain of two, the MAX465/MAX466 exhibit a 1kΩ disabled output resistance. —– —– LE determines whether EN is latched by CS or operates independently. — When the latch-enable input (LE) is con– —– nected to V+, CS—–becomes the latch —–control for the EN input register. If CS is low, —– both the EN and A0 registers are transparent; once CS returns high, both registers are latched. The MAX463–MAX466 multiplexer architecture provides an input transistor buffer, ensuring that no input channels are ever connected together. Select a channel by changing A0's state (A0 = 0—for – channel A, and A0 = 1 for channel B) and pulsing CS low (see Tables 1a, 1b). Figure 4 shows the logic timing diagram. Output —– Disable (MAX463–MAX466) When the enable input (EN) is driven to a TTL low state,—–it enables the MAX463–MAX466 amplifier outputs. When EN is driven high, it disables the amplifier outputs. The tCS CS tH tSU A0 tH tSU EN tON tOFF HIGH-Z OUTPUTS LE = V+ tPD tSW Figure 4. Logic Timing Diagram 10 ______________________________________________________________________________________ Two-Channel, Triple/Quad RGB Video Switches and Buffers —– CS —– EN A0 Enables amplifier outputs. Selects channel A. Enables amplifier outputs. Selects channel B. 0 0 0 0 1 0 1 X Disables amplifiers. Outputs high-Z. X Latches all input registers. Changes nothing. X —– CS FUNCTION 0 1 Table 1b. Amplifier and Channel Selection with LE = GND —– When LE is connected to ground, —– the EN register is transparent and independent of CS activity. This allows all MAX463–MAX466 devices —– to be simultaneously shut down, regardless of the CS input —– state. Simply connect LE to ground and connect all EN inputs together (Figure 5a). For the MAX464 and MAX466, LE must be hardwired to either V+ or ground (rather than driving LE with a gate) to prevent crosstalk from the digital inputs to IN0A. —– EN A0 0 0 0 0 0 1 0 1 0 0 1 1 1 0 X 1 1 X FUNCTION Enables amplifier outputs. Selects channel A. Enables amplifier outputs. Selects channel B. Disables amplifiers. Outputs high-Z. A0 register = channel A Disables amplifiers. Outputs high-Z. A0 register = channel B Enables amplifier outputs, latches A0 register, programs outputs to output A or B, according to the setting of A0 at —– CS's last edge. Disables amplifiers. Outputs high-Z. Another option for output disable is to connect LE to V+, parallel the outputs of several MAX463-MAX466s, and use —– EN to individually disable all devices but the one in use (Figure 5b). When the outputs are disabled, the off isolation from the analog inputs to the amplifier outputs is typically 70dB at 10MHz, all inputs driven with a 4V P-P sine wave and a 150Ω load impedance. Figure 6 shows the test circuits used to measure isolation and crosstalk. EN MAX463– LE MAX466 AO CS MAX463– MAX466 +5V SHUTDOWN LE EN EN AO MAX463– LE MAX466 CS MAX463– MAX466 +5V LE EN NOTE: ISOLATION RESISTORS, IF REQUIRED, NOT SHOWN. (a) (b) –—– –—– Figure 5. (a) Simultaneous Shutdown of all MAX463–MAX466, (b) Enable (EN) Register Latched by CS ______________________________________________________________________________________ 11 MAX463–MAX470 Table 1a. Amplifier and Channel Selection with LE = V+ MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers MAX467–MAX470 MAX467–MAX470 150Ω 75Ω 150Ω 75Ω VIN = 4VP-P AT 10MHz, RS = 75Ω * * VIN = 4VP-P AT 10MHz, RS = 75Ω (a) (b) MAX463–MAX466 MAX463–MAX466 75Ω 150Ω 150Ω 150Ω 150Ω 150Ω 150Ω * * 150Ω LE 150Ω EN +5V VIN = 4VP-P AT 10MHz, RS = 75Ω VIN = 4VP-P AT 10MHz, RS = 75Ω (c) * MAX464/MAX466/MAX468/MAX470 ONLY (d) Figure 6. (a) MAX467–MAX470 Adjacent Channel Crosstalk, (b) MAX467–MAX470 All-Hostile Crosstalk, (c) MAX463–MAX466 All-Hostile Off Isolation, (d) MAX463–MAX466 All-Hostile Crosstalk 12 ______________________________________________________________________________________ Two-Channel, Triple/Quad RGB Video Switches and Buffers 1 2 75Ω 3 4 75Ω 5 6 IN0A GND LE IN1A EN MAX464 GND A0 CS IN2A V– OUT0 75Ω 8 9 –5V 75Ω 10 11 12 75Ω 13 14 V– IN0B V– 4P2T VIDEO SWITCH 7 –5V 27 26 +5V MAX470 25 24 23 –5V 1 22 IN0 OUT0 GND GND IN1 OUT1 V– V– 16 75Ω V– 75Ω 28 GND IN3A OUT1 GND V+ OUT2 IN1B 21 75Ω 2 –5V 3 20 19 75Ω –5V 18 +5V –5V 4 5 6 17 V– V– IN2 OUT2 15 V+ IN2B OUT3 GND 16 13 12 8 15 75Ω IN3B 75Ω GND IN3 V+ OUT3 75Ω –5V –5V 11 75Ω 7 +5V 75Ω 14 75Ω GND MAX463–MAX470 75Ω 10 75Ω V+ 9 75Ω 75Ω 75Ω 75Ω 1 2 75Ω 3 4 75Ω 5 6 EN MAX464 GND A0 CS IN2A V– OUT0 75Ω 8 9 –5V 10 11 12 13 14 28 27 26 24 23 IN0B V– IN1B OUT1 GND V+ OUT2 GND 21 –5V 20 19 18 75Ω +5V 17 75Ω GND IN2B –5V 22 75Ω IN3A V– +5V 25 GND 4P2T VIDEO SWITCH 7 –5V 75Ω LE IN1A V– 75Ω 75Ω IN0A GND V+ OUT3 IN3B 75Ω 16 +5V 15 75Ω FROM OTHER MAX464s Figure 7. Higher-Order RGB + Sync Video Multiplexer ______________________________________________________________________________________ 13 MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers A1 75Ω 2 75Ω 3 4 75Ω 5 6 75Ω –5V 75Ω –5V 75Ω 7 8 9 10 11 12 75Ω 13 14 IN0A GND LE IN1A EN MAX466 GND A0 CS IN2A V– OUT0 27 26 V– IN0B V– IN1B V– OUT1 GND V+ OUT2 25 24 23 –5V 22 21 V+ IN2B OUT3 GND 50Ω 20 19 18 22Ω 50Ω +5V 16 50Ω 15 22Ω 75Ω 3 4 75Ω 5 6 75Ω –5V 75Ω –5V 75Ω 7 8 9 10 11 12 75Ω 13 14 LE IN1A EN MAX466 GND A0 CS IN2A V– OUT0 50Ω 28 27 26 24 23 IN0B V– IN1B –5V 22 22Ω IN3A V– +5V 25 GND QUAD SPDT VIDEO SWITCH 2 IN0A GND V– OUT1 GND V+ OUT2 IN2B GND IN3B 21 –5V 20 19 18 22Ω +5V 17 22Ω GND V+ OUT3 16 +5V 15 22Ω 75Ω Figure 8. 1-of-4 RGB + Sync Video Multiplexer 14 75Ω +5V 75Ω 1 75Ω 17 IN3B 75Ω 75Ω –5V 22Ω GND CS +5V 22Ω IN3A A0 28 GND QUAD SPDT VIDEO SWITCH 1 ______________________________________________________________________________________ 75Ω Two-Channel, Triple/Quad RGB Video Switches and Buffers Paralleling MAX466s to Switch 1-of-4 RGB + Sync Signal Inputs Higher-Order RGB + Sync Video Multiplexing Figure 8 shows a 1-of-4 RGB + sync video mux/amp circuit. The 1kΩ disabled output resistance limits the number of paralleled MAX465/MAX466s to no more than two. The amplifier outputs are connected after a 22Ω isolation resistor and ahead of a 50Ω back-termination resistor, which isolates the active amplifier output from the capacitive load (5pF typ) presented by the inactive output of the second MAX466. Impedance mismatching is minimal, and the signal gain at the cable end is near 1. This minimizes ringing in the output signals. For multiplexing more than two devices, see the section Higher Order RGB + Sync Video Multiplexing, above. Higher-order RGB video multiplexers can be realized by paralleling several MAX463/MAX464s. Connect LE —– —– to V+ and use CS and EN to disable all devices but the one in use. Since the disabled output resistance of the MAX463/MAX464 is 250kΩ, several devices may be paralleled to form larger RGB video multiplexer arrays without signal degradation. Connect series resistors at each amplifier's output to isolate the disabled output capacitance of each paralleled device, and use a MAX469 or MAX470 to drive the output coaxial cables (see Figure 7). _____________________________________________Pin Configurations (continued) GND 1 28 IN0A IN0 1 16 OUT0 IN0 1 16 OUT0 IN1A 2 27 LE GND 2 15 GND GND 2 15 GND GND 3 26 EN IN1 3 14 OUT1 IN1 3 14 OUT1 IN2A 4 25 A0 V- 4 13 V- V- 4 13 V- GND 5 24 CS V- 5 12 V- V- 5 12 V- IN3A 6 IN2 6 11 OUT2 IN2 6 11 OUT2 V- 7 SWITCH 23 V22 OUT0 GND 7 10 V+ GND 7 10 V+ IN0B 8 21 V- GND 8 9 IN3 8 9 V- 9 4P2T TOP VIEW MAX464 MAX466 GND OUT3 20 OUT1 IN1B 10 19 GND GND 11 18 V+ IN2B 12 17 OUT2 GND 13 16 V+ IN3B 14 15 OUT3 DIP/SO MAX467 MAX469 TRIPLE (RGB) BUFFERS DIP/SO MAX468 MAX470 QUAD BUFFERS DIP/SO ______________________________________________________________________________________ 15 MAX463–MAX470 __________Applications Information MAX463–MAX470 Two-Channel, Triple/Quad RGB Video Switches and Buffers __________Typical Operating Circuit _Ordering Information (continued) PART TEMP. RANGE PIN-PACKAGE 0°C to +70°C 28 Narrow Plastic DIP MAX464CWI MAX464C/D MAX464ENI MAX464EWI MAX465CNG MAX465CWG MAX465C/D MAX465ENG MAX465EWG MAX466CNI 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 28 Wide SO Dice* 28 Narrow Plastic DIP 28 Wide SO 24 Narrow Plastic DIP 24 Wide SO Dice* 24 Narrow Plastic DIP 24 Wide SO 28 Narrow Plastic DIP MAX466CWI MAX466C/D MAX466ENI MAX466EWI MAX467CPE MAX467CWE MAX467C/D MAX467EPE MAX467EWE MAX468CPE MAX468CWE MAX468C/D MAX468EPE MAX468EWE MAX469CPE 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 28 Wide SO Dice* 28 Narrow Plastic DIP 28 Wide SO 16 Plastic DIP 16 Wide SO Dice* 16 Plastic DIP 16 Wide SO 16 Plastic DIP 16 Wide SO Dice* 16 Plastic DIP 16 Wide SO 16 Plastic DIP MAX469CWE MAX469C/D MAX469EPE MAX469EWE MAX470CPE MAX470CWE MAX470C/D MAX470EPE MAX470EWE 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 0°C to +70°C 0°C to +70°C 0°C to +70°C -40°C to +85°C -40°C to +85°C 16 Wide SO Dice* 16 Plastic DIP 16 Wide SO 16 Plastic DIP 16 Wide SO Dice* 16 Plastic DIP 16 Wide SO MAX464CNI +5V 10µF 0.1µF MAX465 MAX466 AV = 2 IN0A OUT0 75Ω IN0B 75Ω AV = 2 IN1A OUT1 75Ω IN1B 75Ω AV = 2 IN2A OUT2 75Ω IN2B 75Ω AV = 2 IN3A OUT3 75Ω IN3B A0 75Ω LOGIC -5V 10µF 0.1µF MAX466 ONLY * Dice are specified at TA = +25°C, DC parameters only. 16 ______________________________________________________________________________________