19-0258; Rev 2; 4/95 NUAL KIT MA ATION U EET L H A S V A E T WS DA FOLLO 8x4 Video Crosspoint Switches with Buffers _____________________Block Diagram 8 BUFFERED 8x4 4 75Ω INPUTS SWITCH ARRAY OUTPUT DRIVERS TEMP. RANGE 0°C to +70°C 40 Plastic DIP MAX458CQH MAX458EPL MAX459CPL 0°C to +70°C -40°C to +85°C 0°C to +70°C 44 PLCC 40 Plastic DIP 40 Plastic DIP MAX459CQH MAX459EPL 0°C to +70°C -40°C to +85°C 44 PLCC 40 Plastic DIP PIN-PACKAGE _________________Pin Configurations GND GND N.C. DIN CS 6 IN0 MAX459 N.C. TOP VIEW 5 4 3 2 1 44 43 42 41 40 CE Video Test Equipment Video Security Systems Video Editing PART MAX458CPL WR ________________________Applications ______________Ordering Information UPDATE Data interface can be accomplished by either a 16-bit serial or a 6-bit parallel connection. In the serial mode, the MAX458/MAX459 are SPITM, QSPITM, and MicrowireTM compatible. In parallel mode, the MAX458/MAX459 are compatible with most microprocessor buses. Three-state amplifier output capability makes it possible to multiplex MAX458/MAX459s to form larger switch networks. The output buffers can be disabled individually or the entire device can be shut down to conserve power. 100MHz Unity-Gain Bandwidth 300V/µs Slew Rate Low 0.05° Differential Phase Error Low 0.01% Differential Gain Error Directly Drives 75Ω Cables Fast 60ns Switching Time High-Z Amplifier Output Capability Shutdown Capability 16-Bit Serial and 6-Bit Parallel Address Modes 40-Pin DIP and 44-Pin PLCC Packages SCLK The MAX458/MAX459 are crosspoint switches with eight input channels and four high-speed, buffered output channels. The MAX458 output buffer is configured with a gain of one, while the MAX459 buffer has a gain of two. In each device, any one of eight input lines can be connected to any of four output amplifiers. The output buffers are capable of driving loads of 75Ω. ____________________________Features ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ IN0 75Ω GND GND 75Ω IN6 75Ω AV = 2 75Ω GND GND IN7 75Ω OUT3 GND SERIAL OR PARALLEL DIGITAL INTERFACE & CONTROL SERIAL/PARALLEL INTERFACE (SPI™, QSPI™, MICROWIRE™ COMPATIBLE) 9 37 GND GND 10 36 OUT1 IN3 11 VCC 12 IN4 13 33 VEE VEE 14 32 N.C. IN5 15 31 OUT3 GND 16 30 GND IN6 17 29 A0 35 VCC MAX458 MAX459 34 OUT2 18 19 20 21 22 23 24 25 26 27 28 DIP on last page. A1 AV = 2 GND IN5 75Ω OUT2 38 OUT0 IN2 D0 75Ω 39 GND 8 D1 GND GND 7 D2 75Ω IN4 75Ω OUT1 AV = 2 IN1 GND N.C. 75Ω D3 75Ω GND DOUT GND IN3 8x4 SWITCH ARRAY SHDN 75Ω 75Ω GND IN2 OUT0 GND 75Ω AV = 2 75Ω IN7 GND IN1 GND 75Ω PLCC ™ SPI and QSPI are trademarks of Motorola, Inc. Microwire is a trademark of National Semiconductor Corp. _______________________________________________________________ Maxim Integrated Products Call toll free 1-800-998-8800 for free samples or literature. 1 MAX458/MAX459 _______________General Description MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers ABSOLUTE MAXIMUM RATINGS Total Supply Voltage (VCC to VEE) .........................................12V Positive Supply Voltage (VCC to GND).....................................6V Negative Supply Voltage (VEE to GND) ...................................6V Analog Input/Output Voltage ...........(VCC + 0.3V) to (VEE - 0.3V) Digital Input Voltage ...................................(VCC + 0.3V) to -0.3V Duration of Output Short Circuit to GND (Note 1) ......Continuous Continuous Power Dissipation Plastic DIP (derate 17mW/°C above +70°C) ..............1333mW PLCC (derate 13mW/°C above +70°C) ......................1067mW Operating Temperature Ranges MAX45_C_ _ ........................................................0°C to +70°C MAX45_E_ _......................................................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +160°C Lead Temperature (soldering, 10sec) .............................+300°C Note 1: Outputs may be shorted to any supply pin or ground as long as package power dissipation ratings are not exceeded. 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, VEE = -5V, -2V ≤ VIN ≤ +2V, output load resistor (RL) = 150Ω, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS +2 V STATIC SPECIFICATIONS Input Voltage Range Input Offset Voltage -2 VOS Any channel Input Offset Voltage Match ∆VOS VIN = 0V (Note 2) Power-Supply Rejection Ratio PSRR VS = ±4.75V to ±5.25V 3 VIN = 0V, input programmed to one output On Input Resistance RIN Input programmed to one output Input Capacitance CIN Input channel on or off MAX459 (Note 4) Output Voltage Swing Enabled Output Resistance ±1 0.50 ROUT Disabled Output Capacitance COUT Positive Power-Supply Current ICC VIN = 0V, all amplifiers enabled Negative Power-Supply Current IEE VIN = 0V, all amplifiers enabled 5.0 TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX 0.1 1.0 1.0 2.0 0.25 0.70 TA = +25°C TA = TMIN to TMAX TA = +25°C TA = TMIN to TMAX 60 50 50 40 65 µA pF 0.5 ±3 0.05 4.0 1.0 1.0 12 75 mV MΩ 7 ±2 mV dB ±5 0.1 VIN = 1kHz sine wave VIN = 10MHz sine wave MAX458 MAX459 Disabled Output Resistance 10 60 TA = +25°C VOUT ROUT 15 20 50 IIN MAX458 (Note 3) 5 TA = TMIN to TMAX On Input Bias Current DC Voltage Gain Accuracy 2 TA = +25°C % V Ω MΩ kΩ pF 85 100 75 90 mA mA Positive Supply Current in Shutdown 15 26 mA Negative Supply Current in Shutdown 7 12 mA 2.0 V Logic Input High Voltage VIH (Note 5) Logic Input Low Voltage VIL (Note 5) 0.8 _______________________________________________________________________________________ V 8x4 Video Crosspoint Switches with Buffers (VCC = +5V, VEE = -5V, -2V ≤ VIN ≤ +2V, output load resistor (RL) = 150Ω, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) MAX UNITS Logic Input High Current PARAMETER SYMBOL IIH (Note 3) CONDITIONS 10 µA Logic Input Low Current IIL (Note 3) 10 µA Logic Output High Voltage VOH ISOURCE = 400µA (Note 5) Logic Output Low Voltage VOL ISINK = 1.6mA (Note 5) MIN TYP 4.0 V 0.5 V DYNAMIC SPECIFICATIONS Differential Gain Error (Note 6) DG Differential Phase Error (Note 6) DG MAX458 0.01 MAX459 0.13 MAX458 0.05 MAX459 0.14 MAX458 Slew Rate SR MAX459 Positive transition % degrees 200 Negative transition 150 Positive transition 300 Negative transition 250 MAX458, RL = 75Ω 100 MAX459, RL = 150Ω 90 V/µs Bandwidth (-3dB) BW MHz Input Noise Density en f = 10kHz 20 nV/√Hz Settling Time tS To 0.1% of final value (Note 7) 40 ns Amplifier Disable Time tAOFF 100 ns Amplifier Enable Time tAON 120 ns Channel Switching Time tCSW 60 ns Channel Switching Propagation Delay tCPD 50 ns Switching Transient Glitch See Typical Operating Characteristics 100 mVp-p Adjacent Channel Crosstalk (Note 8) -65 dB Non-Adjacent Channel Crosstalk (Note 9) -65 dB All-Hostile Crosstalk (Note 10) -55 dB All-Hostile Off Isolation (Note 11) -60 dB Note 2: Defined as the DC offset shift when switching between input channels for a given output. Note 3: Voltage Gain Accuracy for MAX458 calculated as (VOUT - VIN) @ (VIN = +2V) - (VOUT - VIN) @ (VIN = -2V) ——————————–————————————————————————————————— 4V Note 4: Voltage Gain Accuracy for MAX459 calculated as (VOUT/2 - VIN) @ (VIN = +1V) - (VOUT/2 - VIN) @ (VIN = -1V) —————————————————————————————————————————————— 2V Note 5: All logic levels are guaranteed over the range of VS = ±4.75V to ±5.25V. Note 6: Differential phase and gain measured with a 40 IRE (285.7mV), 3.58MHz sine wave superimposed on a linear ramp of 0 IRE to 100 IRE (714.3mV). “The IRE scale is a linear scale for measuring, in arbitrary IRE units, the relative amplitudes of the various components of a television signal” (from the “Television Engineering Handbook”, edited by K. Blair Benson, McGraw Hill). This system defines 100 IRE as reference white, 0 IRE as the blanking level, and -40 IRE as the sync peak. The equipment used for the test signal generated 714.3mV (100 IRE) as reference white and -285.7mV (-40 IRE) as sync. The modulation used was 285.7mV (40 IRE), which conforms to the EIA color signal standards. Note 7: For MAX458, step input from +2V to 0V; for MAX459, step input from +1V to 0V. All unused channels grounded and all unused amplifiers disabled. Note 8: Test input channel programmed to an output and grounded through a 75Ω resistor. Adjacent input is programmed to an adjacent output and driven by a 10MHz, 4Vp-p sine wave. Note 9: Same as Note 6 above, except driven input and output are not adjacent to test input/output. Note 10: All inputs but the test input are driven by a 10MHz 4Vp-p sine wave. All outputs except the test output are connected to driven inputs. Note 11: Same as Note 9 above, except with test channel programmed off. _______________________________________________________________________________________ 3 MAX458/MAX459 ELECTRICAL CHARACTERISTICS (continued) MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers TIMING CHARACTERISTICS (Note 12) (VCC = +5V, VEE = -5V, -2V ≤ VIN ≤ +2V, output load resistor (RL) = 150Ω, TA = TMIN to TMAX, unless otherwise noted.) PARAMETER SYMBOL PARALLEL-MODE TIMING (see Figure 1) –—– Address to WR Fall Setup Time tADS –—– Address to WR Rise Hold Time tADH –—– –—– CE Fall to WR Fall Setup Time tCES –—– –—– CE Rise to WR Rise Hold Time tCEH –—– WR Pulse Width Low tWR –—– Data to WR Rise Setup Time tDS –—– Data to WR Rise Hold Time tDH –—– –—————– WR Rise to UPDATE Fall Setup Time tWRS –—————– UPDATE Pulse Width Low tUP –—————– –—– UPDATE Rise to WR Fall Setup Time tUPS CONDITIONS MIN MAX UNITS 20 ns 0 ns 0 ns 0 ns 40 ns 50 ns 0 ns 0 ns 40 ns 25 ns SERIAL-MODE TIMING (see Figure 6) –—– SCLK to CS Fall –—– CS Fall to SCLK Rise tCSO 0 ns tCSS 35 ns SCLK Pulse Width High tCH 50 ns SCLK Pulse Width Low tCL 30 ns DIN to SCLK Rise Setup Time tDS 50 ns DIN to SCLK Rise Hold Time tDH 0 SCLK Fall to DOUT –—– SCLK Rise to CS Rise –—– CS Rise to SCLK Rise –—– CS Pulse Width High tDO ns tCSH 30 ns tCS1 20 ns tCSW 100 ns Note 12: Timing Characteristics are guaranteed by design. 4 ns 200 _______________________________________________________________________________________ 8x4 Video Crosspoint Switches with Buffers MAX458 GAIN vs. FREQUENCY -4 0 PHASE -6 36 72 40 20 0.1 20 40 60 80 100 120 140 1 10 MAX458/459 Fg TOC6 10 D1 IN5 IN2 20mV/div (analog) IN2 +200mV -200mV 100ns/div 100 MAX459 SMALL-SIGNAL PULSE RESPONSE INPUT MAX458/459 Fg TOC8 INPUT UPDATE MAX458/459 Fg TOC3 1 100 +200mV -200mV +100mV OUTPUT OUTPUT 180 100 250 0.1 5V 25ns/div 10 CHANNEL SWITCH TRANSIENT OUT MAX458 SMALL-SIGNAL PULSE RESPONSE -15V 1 GND MAX458 LARGE-SIGNAL PULSE RESPONSE 1V/div 0.1 FREQUENCY (MHz) 1 FREQUENCY (MHz) GND 144 D0 & D2 FREQUENCY (MHz) 2V/div 108 144 MAX458/459 Fg TOC9 0.1 72 108 180 100 250 10 36 INPUT -120 OUTPUT IMPEDANCE (Ω) MAX458/459 Fg TOC7 -80 MAX458/459 Fg TOC2 AMPLITUDE (dB) -40 0.01 0 PHASE OUTPUT IMPEDANCE vs. FREQUENCY CROSSTALK vs. FREQUENCY 0 10 0 FREQUENCY (MHz) TEMPERATURE (°C) 40 1 2 -100mV 10ns/div +200mV OUTPUT -60 -40 -20 0 4 PHASE (DEGREES) 60 0 -2 GAIN 6 PHASE (DEGREES) IEE GAIN MAX458/459 Fg TOC5 2 10V/div (digital) 4 AMPLITUDE (dB) 80 MAX458/459 Fg TOC4 ICC CURRENT (mA) 6 MAX458/459 Fg TOC1 100 MAX459 GAIN vs. FREQUENCY AMPLITUDE (dB) POWER SUPPLY CURRENT vs. TEMPERATURE -200mV 10ns/div _______________________________________________________________________________________ 5 MAX458/MAX459 __________________________________________Typical Operating Characteristics (TA = +25°C, unless otherwise noted.) MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers ______________________________________________________________Pin Description PIN DIP PLCC NAME FUNCTION 1 1 DIN 2, 4, 6, 8, 14, 16, 18, 27, 33, 35 3, 5, 8, 10, 16, 18, 20, 30, 37, 39 Serial Data Input GND 3 4 IN0 Analog Input Channel 0 5 7 IN1 Analog Input Channel 1 7 9 IN2 Analog Input Channel 2 9 11 IN3 Analog Input Channel 3 10, 31 12, 35 VCC Positive Power Supply (+5V). Connect both VCC pins to the positive supply. 11 13 IN4 Analog Input Channel 4 12, 29 14, 33 VEE Negative Power Supply (-5V). Connect both VEE pins to the negative supply. 13 15 IN5 Analog Input Channel 5 15 17 IN6 Analog Input Channel 6 17 19 IN7 Analog Input Channel 7 19 21 SHDN Shutdown, active high. Connect to GND if not used. 20 22 DOUT Serial Data Output used for daisy-chaining devices. 21 23 D3 Parallel Digital Channel Input Address Bit 3 22 25 D2 Parallel Digital Channel Input Address Bit 2 23 26 D1 Parallel Digital Channel Input Address Bit 1 24 27 D0 Parallel Digital Channel Input Address Bit 0 25 28 A1 Parallel Digital Amplifier Output Address Bit 1 26 29 A0 Parallel Digital Amplifier Output Address Bit 0 28 31 OUT3 Amplifier 3 Analog Output 30 34 OUT2 Amplifier 2 Analog Output 32 36 OUT1 Amplifier 1 Analog Output 34 38 Amplifier 0 Analog Output 36 40 37 41 38 42 OUT0 –—– CE –—– WR –—————– UPDATE 39 43 40 — Ground Chip Enable, used in parallel mode. Keep high for serial operation. Write Low, latches input registers in parallel mode. Hold high for serial operation. Update Low, latches amplifier registers in parallel mode. Hold high for serial operation. Serial Clock 44 SCLK –—– CS 2, 6, 24, 32 N.C. Not Internally Connected Chip Select, used in serial operation. Hold high for parallel mode of operation. Note: All GND pins must be grounded for optimum crosstalk performance. 6 _______________________________________________________________________________________ 8x4 Video Crosspoint Switches with Buffers MAX458/MAX459 2 3 IN0 75Ω 4 5 IN1 75Ω 6 MAX458 MAX459 7 IN2 75Ω 8 35 9 IN3 75Ω 34 OUT0 75Ω 75Ω 0.1µF 10 11 VCC IN4 OUT0 ENABLE 33 75Ω 0.1µF 12 VEE 1 13 IN5 14 DOUT 39 15 IN6 DIN 20 75Ω 40 75Ω CS 19 16 SERIAL INTERFACE SCLK SHDN 17 IN7 75Ω 18 IN0 32 OUT1 75Ω IN7 OUT1 ENABLE IN0 75Ω 31 30 IN7 0.1µF VCC OUT2 75Ω 75Ω OUT2 ENABLE IN0 29 28 IN7 OUT ENABLE 4 24 D0 23 D1 PIN NUMBERS APPLY TO DIP PACKAGE. 22 D2 21 D3 OUT3 ENABLE 26 0.1µF OUT3 75Ω VEE 75Ω 27 38 37 36 25 A0 A1 CE WR UPDATE PARALLEL INTERFACE Figure 1. Block Diagram and Typical Operating Circuit _______________________________________________________________________________________ 7 MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers ANALOG INPUTS IN0 IN7 ••• UPDATE WR INPUT REGISTER 1 SWITCH REGISTER 1 CONTROL 0 ••• CE 7 OUT0 8-1 MUX ••• SWITCH REGISTER 2 CONTROL 0 ••• INPUT REGISTER 2 8-1 MUX OUT1 7 A0 A1 ••• SWITCH REGISTER 3 CONTROL 0 ••• INPUT REGISTER 3 8-1 MUX OUT2 7 ••• SWITCH REGISTER 4 CONTROL D0 D1 D2 D3 0 ••• INPUT REGISTER 4 MAX458 MAX459 8-1 MUX 7 L = TRANSPARENT H = LATCHED CS = HIGH, SCLK = DIN = LOW Figure 2. Parallel-Logic Block Diagram 8 _______________________________________________________________________________________ OUT3 8x4 Video Crosspoint Switches with Buffers Analog Section The MAX458/MAX459 video crosspoint switches consist of a high-speed 32 (8x4) switch array with wide-bandwidth line drivers (Figure 1). This design allows makebefore-break switching to reduce output noise and glitches, but the inputs will not short together. It also provides high input impedance and low input capacitance, so no input buffer amplifier is needed. However, because different transistors provide gain depending on the input selection, the DC offset voltage shifts slightly when a new input is switched in. The change in offset voltage is typically 3mV. All output buffers will drive back-terminated 50Ω, 75Ω, or higher impedance lines with up to 100pF capacitance. The amplifier outputs can be disabled, which is useful for creating large arrays. When disabled, the MAX458 presents an output impedance of approximately 1MΩ. The MAX459 disabled output impedance is 1kΩ (to ground), due to the internal feedback resistors used to achieve the gain of two. –—– –—————– During power-on, if CS and UPDATE are held high, all output amplifiers are disabled. In a large array, this feature prevents two ON paralleled amplifiers from distorting each other’s signals. The amplifiers can be programmed to come up in any state simultaneously at any time after power-on. See the Creating Large Arrays section. 1 DIN CS SCLK UPDATE MAX458 MAX459 SHUTDOWN 19 20 A1 A0 Output Amplifier Selected L L 0 L H 1 H H L H 2 3 Table 2. Input Selection D2 D1 D0 Input Channel Selected L L L L 0 L L L H 1 L L H L 2 L L H H 3 L H L L 4 L H L H 5 40 V CC 39 L H H L 6 L H H H 38 H X X X CE A0 26 D0 AMPLIFIER SELECT A0 25 AMPLIFIER SELECT A1 24 DATA BIT D0 D1 23 DATA BIT D1 SHDN D2 22 DATA BIT D2 DOUT D3 21 A1 Table 1. Amplifier Selection D3 UPDATE 37 WRITE 36 CHIP ENABLE (SELECT) WR Digital Section—Parallel Mode The MAX458/MAX459 have two register banks—an input register and a switch register (Figure 2). Each of these registers is either latched (when the control input is high) or transparent (when the control –—– input –—– is low). The input register is controlled by WR and CE–— and – is selected by the decode of A0 and A1. If both W R and –—– CE are low, the input register selected by A0 and A1 is transparent, and the state of D0–D3 is presented to the switch register. The other three input registers remain –——— ——– latched. If D0–D3 change before UPDATE is asserted (goes low), the new data (the changed –—– D0–D3) –—– will then be latched in the switch register. If WR or CE is high, all input registers are latched and their data is presented DATA BIT D3 Pin numbers apply to DIP package. Figure 3. Parallel Connection (only logic pins shown) 7 Disable output amplifier selected by A0, A1. Table 3. Writing Data –—– –—– –—————– CE WR UPDATE FUNCTION H X H Device not selected or is operating in seriX H H al mode. Both registers are latched. Data in input registers passes through H X L switch registers. Output reflects data in X H L input registers. Input register of selected amplifier is transL L H parent. Switch registers are latched. Other input registers are latched. All switch registers and selected input register are transparent. Selected amplifier (choL L L sen by state of A0, A1) reflects input data. Other amplifiers reflect data that had been latched into the input registers previously. _______________________________________________________________________________________ 9 MAX458/MAX459 _______________Detailed Description MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers –—– –—– to their switch registers. As long as either WR or CE is high, the input register will not change. The switch register will –———— —– pass any new data on the falling transition of UPDATE. Each register of the switch-register bank controls the –————— – inputs to one amplifier. With UPDATE low, the switch registers are transparent and switch connection con–———is —— – trolled by the input register. However, if UPDATE is high, the switch register is latched and any change in data by the input register will not affect the amplifier output state. Two register banks are used so that data can be loaded into input registers without affecting the switch/amplifier selection. This allows amplifiers to be programmed and then changed simultaneously. When the registers are not latched, they are made transparent. Use data bit D3 to disable the amplifier selected by A0–A1 and place its output in high-impedance mode. As an example, the code to disable OUT0 is as follows: Pin Name: D3 D2 D1 D0 A1 A0 Input Code: 1 X X X 0 0 — – When operating in parallel mode, CS must be wired high and SCLK and DIN should be grounded, as shown in Figure 3. Refer to Figure 4 for the correct timing relationships. A0/A1 Digital Section—Serial Mode The MAX458/MAX459 use a three-wire serial interface that is compatible with SPI, QPSI and Microwire interfaces.–—–Serial shown –———mode, ——– –—– in Figure 5, is enabled –—– when WR, UPDATE, and CE are held high and CS goes low. Figures 6 and 7 show serial-mode timing. Figure 8 shows the MAX458/MAX459 configured for serial operation. Figure 9 shows the Microwire connection, and Figure 10 shows the SPI/QSPI connection. The serial output, DOUT, allows cascading of two or more crosspoint switches to create larger arrays. The data at DOUT is delayed by 16 cycles plus one clock pulse width –— at– DIN. DOUT changes on SCLK’s falling –—– edge when CS is low. When CS is high, DOUT remains in the state of the last data bit. The MAX458/MAX459 input data in 16-bit blocks. SPI and Microwire interfaces output data in 8-bit blocks, thereby requiring two write cycles to input data. The QSPI interface allows variable word lengths from 8 to 16 bits and can be loaded into the crosspoint in one write cycle. SPI and Microwire limit clock rates to 2MHz, while the QSPI maximum clock rate is 4MHz. ADDRESS VALID tADS tADH CE tCES tCEH tWR WR tDS D0–D3 tDH tUPS DATA VALID tWRS UPDATE tUP Figure 4. Parallel-Mode Timing 10 ______________________________________________________________________________________ 8x4 Video Crosspoint Switches with Buffers IN7 ••• ONE SHOT ANALOG INPUTS IN SWITCH REGISTER 0 CLK ••• 0 7 CONTROL INPUT CS MAX458/MAX459 IN0 DIN 8-1 MUX OUT0 D Q ••• 16-BIT SHIFT REGISTER SWITCH REGISTER 1 ••• 0 SCLK 8-1 MUX OUT1 7 ••• MAX458 MAX459 ••• 0 SWITCH REGISTER 2 8-1 MUX OUT2 7 ••• Q D OUT ••• 0 SWITCH REGISTER 3 8-1 MUX OUT3 7 DOUT L = TRANSPARENT H = LATCHED WR = CE = UPDATE = HIGH Figure 5. Serial-Mode Logic Block Diagram ______________________________________________________________________________________ 11 MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers tCSW tCSH ••• CS tCH tCSS tCS0 tCS1 tCL SCLK ••• tDH tDS DIN D0 ••• D3 (OUT3) D2 (OUT3) tD0 D1 (OUT0) D0 (OUT0) ••• DOUT D3 DATA FROM PREVIOUS WRITE CYCLE D2 D1 D0 D3 Figure 6. Serial-Mode Timing CS SCLK DIN D3 D2 D1 D0 D3 D2 OUT3 D1 D0 D3 D2 OUT2 D1 D0 D3 D2 OUT1 D1 D0 D1 D0 OUT0 DOUT D3 D2 D1 D0 D3 DATA FROM PREVIOUS WRITE CYCLE D2 D1 D0 D3 D2 D1 D0 D3 D2 Figure 7. Serial-Mode Data Sequence SERIAL DATA IN 1 DIN CS SCLK MAX458 MAX459 SERIAL DATA OUT 20 39 CHIP SELECT SERIAL CLOCK UPDATE 38 VCC WR 37 VCC CE 36 VCC A0 26 A1 25 D0 19 40 MAX458 MAX459 SCLK SK DIN SO CS I/O DOUT MICROWIRE PORT SI 24 D1 23 SHDN D2 22 DOUT D3 21 THE DOUT-SI CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX458/MAX459, BUT MAY BE USED FOR DATA-ECHO PURPOSES. Pin numbers apply to DIP package. Figure 8. Serial Connection (only logic pins shown) 12 Figure 9. Microwire Connection ______________________________________________________________________________________ D3 8x4 Video Crosspoint Switches with Buffers MAX458/MAX459 IN_ SCK DIN MOSI CS I/O DOUT SPI/QSPI PORT RETURN CURRENT MOSO IN_ CPOL = 0, CPHA = 0 THE DOUT-MOSO CONNECTION IS NOT REQUIRED FOR WRITING TO THE MAX458/MAX459, BUT MAY BE USED FOR DATA-ECHO PURPOSES. Figure 10. SPI/QSPI Connection __________Applications Information Grounding and Bypassing, PC Board Layout As with all analog circuits, good PC board layout, proper grounding, and careful component selection are crucial for realizing the full AC performance of high-speed amplifiers such as the MAX458/MAX459. For optimal performance: 1) Use a large, low-impedance analog ground plane. With multilayer boards, the ground plane(s) should be located on the layer that does not contain signal traces. Connect all GND pins to the analog ground plane. 2) Minimize trace area at the circuit’s critical high-impedance nodes to prevent unwanted signal coupling. Surround analog inputs with an AC ground trace (bypassed DC power supply, etc.). The analog input pins of the MAX458/MAX459 have been separated with AC ground pins (GND, VCC, VEE) to minimize parasitic coupling, which can degrade crosstalk. 3) Connect the coaxial-cable shield to the ground side of the 75Ω terminating resistor at the ground plane to further reduce crosstalk (Figure 11). 4) 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, you may need 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. GROUND PLANE MAX458 MAX459 SCLK RETURN CURRENT Figure 11. Low-Crosstalk Layout. Return current from termination resistor does not flow through the ground plane. Creating Larger Arrays The MAX458/MAX459 assume a high-impedance state on power-up if the inputs are not being programmed to any particular state during that time. They also are in a high-impedance state when disabled. This feature makes it possible to create larger arrays than 8x4 without special programming, other than ensuring that your program doesn’t turn on two paralleled outputs simultaneously. Testing has shown no degradation of differential gain or phase when the outputs are connected in parallel. The MAX458/MAX459’s input registers remain active during shutdown, which allows the crosspoint to be programmed while the devices are shut down. As a result, all outputs may be simultaneously brought to any state, including disabled. Just program all of the MAX458/ MAX459s into shutdown, and enter the program of your choice by selecting the desired inputs and outputs. Taking SHDN low takes the device(s) out of shutdown. A power-on reset circuit causes the output amplifiers to power up in –the disabled whether or not SHDN ——— ——– –mode, —– is applied, if UPDATE and CS are high. The number of MAX458s that can be paralleled is limited by capacitive loading on each output, which must not exceed 100pF. Each input presents approximately 7pF of load, and each output presents approximately 12pF. Therefore, the MAX458/MAX459 will drive a maximum of 14 inputs, or 7 outputs and 2 inputs, or any other combination resulting in less than a 100pF load. Adding isolation resistors enables more MAX458s to be paralleled (see the Driving Capacitive Loads section). ______________________________________________________________________________________ 13 MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers Driving Capacitive Loads When driving loads greater than 100pF, you may need a capacitance compensating resistor in series with the output of each affected amplifier. The required resistor will depend on load as well as capacitance. For 150Ω or higher load resistances and capacitance up to 1000pF, use a 2.4Ω resistor. For 100Ω loads, use a 4.7Ω resistor. If an output amplifier is loaded with a pure capacitance or with the inputs of other MAX458/MAX459s, the resistors will cause no degradation of gain or other performance because of the high impedance of the crosspoints. However, resistive loads may cause a reduction in gain. Daisy-Chaining Devices The serial output, DOUT, allows cascading of two or more crosspoint switches to create larger arrays. The data at DOUT is the DIN data delayed by 16 cycles plus one clock on SCLK’s falling –—– width. DOUT changes —– edge when CS is low. When CS is high, DOUT remains in the state of the last data bit. Any number of MAX458/MAX459 crosspoint switches can be daisy-chained by connecting the DOUT of one device to the DIN of the next device in the chain, as shown — in– Figure 12. For proper timing, ensure that both tCSS (CS low to SCLK high) and tCL are greater than tDO + tDS. DOUT is a TTL-compatible output with an active — pull– up. It does not become high impedance when CS is high. CS SCLK SERIAL DATA INPUT DOUT DIN 1 40 MAX458 39 MAX459 28 OUT3 30 OUT2 32 OUT1 20 34 OUT0 1 40 MAX458 39 MAX459 28 30 32 DOUT 20 34 Figure 12. 16x4 Crosspoint Switch Using Serial "Daisy Chain" Connection 14 ______________________________________________________________________________________ 8x4 Video Crosspoint Switches with Buffers MAX458/MAX459 ____Pin Configurations (continued) TOP VIEW DIN 1 40 CS GND 2 39 SCLK IN0 3 GND 4 IN1 5 38 UPDATE MAX458 MAX459 37 WR 36 CE GND 6 35 GND IN2 7 34 OUT0 GND 8 33 GND IN3 9 32 OUT1 V CC 10 31 V CC IN4 11 30 OUT2 V EE 12 29 V EE IN5 13 28 OUT3 GND 14 27 GND IN6 15 26 A0 GND 16 25 A1 IN7 17 24 D0 GND 18 23 D1 SHDN 19 22 D2 DOUT 20 21 D3 DIP ______________________________________________________________________________________ 15 MAX458/MAX459 8x4 Video Crosspoint Switches with Buffers ________________________________________________________Package Information DIM A A1 A2 A3 B B1 C D D1 E E1 e eA eB L α D1 E A2 A3 E1 D A α INCHES MAX MIN 0.200 – – 0.015 0.175 0.125 0.080 0.055 0.020 0.016 0.065 0.045 0.012 0.008 2.075 2.025 0.090 0.050 0.625 0.600 0.575 0.525 0.100 BSC 0.600 BSC 0.700 – 0.150 0.120 15˚ 0˚ MILLIMETERS MIN MAX – 5.08 0.38 – 3.18 4.45 1.40 2.03 0.41 0.51 1.14 1.65 0.20 0.30 51.44 52.71 1.27 2.29 15.24 15.88 13.34 14.61 2.54 BSC 15.24 BSC – 17.78 3.05 3.81 0˚ 15˚ 21-348A A1 C e L 40-PIN PLASTIC DUAL-IN-LINE PACKAGE eA B1 eB B DIM A2 C e D1 D B1 D2 B A A1 A2 A3 B B1 C D D1 D2 D3 e INCHES MAX MIN 0.180 0.165 0.110 0.100 0.156 0.145 – 0.020 0.021 0.013 0.032 0.026 0.011 0.009 0.695 0.685 0.655 0.650 0.630 0.590 0.500 REF 0.050 REF MILLIMETERS MIN MAX 4.19 4.57 2.54 2.79 3.68 3.96 0.51 – 0.33 0.53 0.66 0.81 0.23 0.28 17.40 17.65 16.51 16.64 14.99 16.00 12.70 REF 1.27 REF 21-350A A3 D3 D1 D 16 A1 A 44-PIN PLASTIC LEADED CHIP CARRIER PACKAGE ______________________________________________________________________________________