19-0978; Rev 0; 7/87 General Description The MAX482 is a unity-gain stable, 5S0MHz video amplifier capable of driving a 75 ohm load directly. The MAX453, MAX454, and MAX455 combine the 50MHz video ampli- fier, of the MAX452, with an on-board multiplexer offering 2, 4, or 8 channels respectively. All of the MAX452 family devices operate from +5V supplies and typically con- sume only 250mW. Optimized for video applications, these amplifiers will directly drive a 150 ohm load to +2V, and will swing +1V into a75 ohm load. All amplifiers are unity-gain stable and do not require external frequency compensation com- ponents. The MAX453/454/455 operate as positive-gain amplifiers, gain being set by two external resistors. Since they are connected as non-inverting amplifiers, their minimum closed-loop gain is OdB. In most applications the amplifiers closed-loop gain will be set at OdB or +6dB (1 V/V or 2 VM), which guarantees a minimum bandwidth of 25MHz. Applications Video signal multiplexing 75 ohm cable drivers Driving flash converters Video Crosspoint Switches MAALM@I CMOS Video Multiplexer/Amplifier Features @ - Unity-gain bandwidth of 50MHz typ. @ Low input capacitance: 7pF typ. @ No frequency-compensation required @ Low power operation: 250mW typ. @ Low bias current: 10pA typ. @ Directly drives 75 ohm cable @ 70 dB typical OFF isolation at 4 MHz Ordering Information PART TEMP. RANGE PACKAGE MAX452CPA 0Cto +70C 8 lead plastic DIP MAX452CSA 0Cto +70C 8 lead smail-outline MAX452C/D 0Cto +70C Dice MAX452EPA -40C to +85C 8 lead plastic DIP MAX452EJA -40C to +85C 8 jead CERDIP MAX452MJA -55C to + 125C 8 lead CERDIP MAX453CPA 0Cto +70C 8 lead plastic DIP MAX453CSA 0Cto +70C 8 lead small-outline MAX453EPA -40C to +85C 8 lead plastic DIP MAX453EJA -40C to +85C 8 lead CERDIP MAX453MJA -55C to + 125C 8 lead CERDIP MAX454CPD 0C to +70C 14 lead plastic DIP MAX454CSD 0C to +70C 14 lead small-outline MAX454EPD -40C to +85C 14 lead plastic DIP MAX454EJD -40C to +85C 14 lead CERDIP {Ordering information Continued on Last Page.) Pin Configurations Top View Vout -IN vt +I1N MIAXI/A maxas4 F2I VIAXI/VI VIAXI/V maxas3 FI v* Vout -IN vt IN7 6} NC ING NC (NS Nc IN4 MAXUM For free samples & the latest literature: http:/;www.maxim-ic.com, or phone 1-800-998-8800 Maxim Integrated Products 1 S/P/E/ESPXVNMAX452/3/4/5 CMOS Video Multiplexer/Amplifier ABSOLUTE MAXIMUM RATINGS Total Supply Voltage (Vtto V7) 20. eee 12V Positive ey ony Vetose. veel GND) oo. ll. +12V Negative Supply Voltage, V- (rel. GND) 0.0.0.0. 0....00000. 00. -12V Analog Input Voltage .:...... . V4)40.3Vt0(V)-0.3V Digital Input Voltage ................00.0000, -0.3Vto (Vt)+0.3V Storage Temperature Range ................... -65C to + 160C Operating Temperature Range MAX45SC MAX4530, 9 MAX454C,MAX455C 0 eee 0Cto +70C MAX452E, MAX453E, MAX454E,MAX455E ...... 00.2 -40C to +85C MAX452M,MAX453M, MAX454M,MAX455M o.oo eee -55C to + 125C Lead temperature (Soldering, 10 sec).........00.0. 0.0.00 300C Duration of Output Short-Circuit to ground ................ Indefinite Input Current, power on or off Digital Inputs... 6... 6. cece eee +20mA Allotherpins 0.00... ee +50 mA Continuous Total Power Dissipation (Ta= + 70C) 8 Pin CERDIP (derate 8.0mW/C above 70C) ............ 640mw 14 Pin CERDIP (derate 9.5mw/C above 70C)............ 760mW 20 Pin CERDIP (derate 11.1mW/C above 70C)... 890mWw 8 Pin Plastic DIP (derate 8.3mW/C above 70C)......... 660mWw 14 Pin Plastic DIP (derate 10.0mW/C above 70C)........ 800mWw 20 Pin Plastic DIP (derate 11.1mW/C above 70C)... ..... 890mWw 8 Pin Small-Outline (derate 5.9mW/C above 70C) 1.2... 320mW 14 Pin Small-Outline (derate 8.7mW/C above 70C) ....... 480mWw 20 Pin Small-Outline (derate 10.0mW/C above 70C) ...... 550mWw Stresses above 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 above 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 MAX452/3/4/5 (V+ = +5V, V~- =-5V, -2V< Vin< + 2V, Output Load Resistor= 150, Ta = +25C unless otherwise noted) PARAMETER | SYMBOL | CONDITIONS [MIN. TYP. MAX.| UNITS VIDEO AMPLIFIER (MAX452/3/4/5) . Input Voltage Range Vin Over Temperature Range (Note 2) | -2 2 v Input Offset Voltage Vos 2 5 mV Offset Voltage Drift AVos/AT | (Note 5) 20 100 | pv/c Input Bias Current Ta = +25C (Note 1) 0.01 10 Ip Over Temperature Cc 1 10 nA Range (Notes 1,2) E 3 30 M 50 500 Input Resistance Rw 1011 Oa Open-Loop Voltage Gain R, = 10000, 180 260 Avot R, =1500, 45 70 VN R, =750, 25 Open-Loop Gain Drift AAvoL/AT | RL = 1500 0.5 %/C Common-Mode Rejection CMRR -2V <VIN< +2 60 80 dB Ratio ; Power Supply Rejection PSRR +4.5V to +5.5V dB Ratio Slew Rate SR (Note 5) 150 300 V/s Note 1; Input bias current includes the muitiplexer's ON-state leakage current for the MAX453, MAX454 and MAX455. Note 2: Operating temperature range for C devices Is 0C to 70C, for E devices Is -40C to + 85C, and for M devices Is -85C to + 125C. Note 3: Input test signal: 3.58MHz sInewave of amplitude 40 IRE superimposed on a linear ramp (Oto 100 IRE). The amplifier is operated at a galn of 2V/V while driving a 150 ohm load. Note 4: Guaranteed over the voltage range, V~< Viy <Vt. Note 5: Guaranteed by design. (Continued on next page) 2 MAXIMCMOS Video Multiplexer/Amplifier ELECTRICAL CHARACTERISTICS MAX452/3/4/5 (Continued) (V+ = +5V, V7 =~-8V, -2V<Vin< +2V, Output Load Resistor=150Q, Ta = +25C unless otherwise noted) PARAMETER | symBo | | CONDITIONS | min. Typ. max. | UNITS VIDEO AMPLIFIER (MAX452/3/4/5) -3dB Bandwidth GBW1 Ay =0dB, R_ =750, (Note 5) 30 50 MHz -3dB Bandwidth GBW2 Ay =6aB, R, = 1509 (Note 5) 25 40 MHz Differential Phase Error DP Wvtaea 14/8 WN se 8 5) te deg Differential Gain Error DG (Notes 3, 5) 0.5 % Settling-Time to 1% ts AV=1V, R_ = 1500, Ay =6dB 50 ns Output Impedance Rout f=100kHz, Ay= 0dB 2 OD Full-Scale Output Current lout R= 1500, +14 +20 mA Output Voltage Swing Vout R, = 1500 +21 +3.0 V Input Noise, dc to 40MHz Vn (Note 5) 0.15 0.5 MVims Operating Supply Voltage VvtVe +45 +55 V Supply Current Ig Vin = OV 20 25 30 mA MULTIPLEXER (MAX453/4/5) Input Voltage Range Vin Over Temperature -2 2 Vv OFF Input Leakage Current Ty = +25C (Note 4) 0.01 10 lore | Suerremeeans , 3] M 50 500 Logic Low Threshold Vit 0.8 v Logic High Threshold Vin 2.4 v Input Pullup/down Current hue 5 20 pA Turn-ON Time ton (Note 5) 75 120 ns Turn-OFF Time toe (Note 5) 25 60 ns Break-Before-Make Delay to (Note 5) 10 50 ns Channel ON Capacitance Con (Note 5) 7 15 pF Channel OFF Capacitance} Cop (Note 5) 3.5 12 pF ty = 4MHz, Rg = 752 (Note 5) Channel OFF Isolation OIRR Channel 2 to Channel 3 45 55 dB All other Channels 60 70 Note 1: Input bias current Includes the multiplexers ON-state leakage current for the MAX453, MAX454 and MAX455. Note 2: Operating temperature range for C devices Is 0C to 70C, for E devices is -40C to + 85C, and for "M" devices Is -55C to + 125C. Note 3: Input test signal: 3.58MHz sinewave of amplitude 40 IRE superimposed on a linear ramp (0 to 100 IRE). The amplifier Is operated at a gain of 2V/V while driving a 150 ohm load. Note 4: Guaranteed over the voltage range, V-< Vin <Vt. Note ; Guaranteed by design. MAXIM 3 S//E/ESPXVNMAX452/3/4/5 CMOS Video Multiplexer/Ampilifier MAX452 AND MAX455 DIFFERENTIAL GAIN . MAX452 DIFFERENTIAL PHASE Input test signal: 3.58MHz sinewave of amplitude 40 IRE superimposed on a linear ramp (Oto 100 IRE). The amplifier Is operated at a galn of 2V/V while driving a 150 ohm load. MAX455 DIFFERENTIAL PHASE MAX455 PULSE RESPONSE OUTPUT INPUT OPEN-LOOP GAIN vs. FREQUENCY OPEN-LOOP GAIN vs. TEMPERATURE S 1000 Ri= 1KQ Ta= 25C & 700 ~ ad 500 s 3 ~ R= 1500 Go 0 2 Ul 200 G g 150 a. F100 8 9 7 Z a 50 ai 8 w S 3 uy (2 75Q a. 15 10 0.2505 1 2 4 8 16 32 64 -55 -35 -15 +5425 +45+65+85 +125 FREQUENCY (MHz) FREE - AIR TEMPERATURE (c) 4 MAXIMCMOS Video Multiplexer/Amplifier Pin Description PIN PIN NUMBER FUNCTION NAME MAX452 MAX453 MAX454 MAX455 vt 6 6 12 18 Positive Supply, + 5V v- 3 3 4 6 Negative Supply, -5V Vour 8 8 14 20 Amplifier output -IN 7 7 13 19 Amplifier's inverting input +iN 5 - - - Amplifiers non-inv. input INO - 4 7 5 Analog input, channel 0 1N1 - 5 8 7 Analog input, channel 1 IN2 - - 10 9 Analog input, channel 2 IN3 - - ah 10 Analog input, channe! 3 IN4 - - - 11 Analog input, channel 4 IN5 - - - 13 Analog input, channel 5 IN6 - - - 15 Analog input, channel 6 IN7 - - - 17 Analog input, channel 7 A2 - - - 1 Channel select, MSB Al - - 1 2 Channel select AO - 1 2 3 Channel select, LSB GND - 2 3 4 Logic Ground Detailed Description Table 1. The video amplifier is a low gain, wideband op-amp Gain and Load Resistor Selection cri ereanamersoimicccwachiediess [GAIN FB AT RE Row small gain error. However, this can readily be trimmed by (VN) (MHz) (Q) (Q) (Q) adjusting the gain-setting resistors. 1 50 0 oo 75 The MAX452/3/4/5 series are unity-gain stable when 2 40 1k 1k 150 driving resistive loads. They are optimized for driving 75 ohms at unity gain or 150 ohms at a gain of 2V/V with no 5 30 4k 1k 390 frequency compensation components required. Gen- 10 18 9k 1k 750 erally, for the best transient response, the load resistance should be (in ohms) 75 x GAIN(V/V). Thus, at a gain of + 6dB (2V/V), the amplifie:s optimal load is 150 ohms. Ifa higher resistive load is used, the amplifier will show peaking near its -3dB frequency. If a capacitive load is being driven, such as the input to a flash converter, the load should be isolated by a series resistor to limit amplifier ringing, see Figure 4. The bandwidth of the amplifier is affected by both the closed-loop gain and the load resistor. Table 1 lists the -3dB rolloff frequency for a MAX453/4/5 with different gains and optimal resistive loads. The MAX452, which doesnt have the input multiplexer, runs about 20% higher in bandwidth. MAXIM The multiplexers feature break-before-make switches to insure that no two channels are ever connected together. Low DC offset voltage and high bandwidth allow the MAX455 to be cascaded to form a 64 channel system while retaining video signal fidelity. Figure 1 shows a typical application of the MAX455. The circuit is being used to drive a back terminated 75 ohm cable. R3 and R4 terminate the cable at both ends. R3 also attenuates the signal by a factor of two, so to make up for the signal loss, the amplifier is run at a gain of 2V/V. This arrangement provides unity gain from signal inputto S/b/E/CSPXVNMAX452/3/4/5 CMOS Video Multiplexer/Amplifier cable output. Amplifier closed-loop gain is set by R1 and R2 giving, Vour Gx (R1 + R2) Vn (Gx R2) + (RI + RQ) Where G is the open-loop gain of the amplifier, about 7OVAN with a 150 ohm load. Capacitors C1 and C2 are power supply bypass capacitors. Multiplexer channels are selected by the AO, A1, and A2 pins. These logic pins are compatible with either TTL or CMOS logic. The GND pin (which is a logic ground, NOT an analog ground) should be connected to digital ground. Table 2 shows selected channels for the different states of the control lines. If AO, A1, and A2 are lett floating, internal pullup/pulldown sources will hold AQ and A1 low, and A2 high. Thus, channel 0 is the default channel for the MAX453 and MAX454, while channel 4 is the default channet for the MAX455. Pullup/pulldown currents are typically around SpA. Table 2. Channel Selection MAX453 MAX454 MAX455 AO Channel | A1 AO Channel | A2 Al AO Channel L o* L L o* L L L 0 H 1 L H 1 L L H 1 H L 2 L H L 2 H H 3 L H H 3 H L L 4* H L H 5 H H L 6 H H H 7 *Defauit channel If selection pins are left floating. vt +5.0V ct | | 0.1pF 18 = MAX455 Ra 75 aw IN7 75Q cable ING R4 13 + = 750 IN5 Your ~ IN4 * Ri = ANALOG f 5 = INPUT 10 8.8pF T 1.07kO IN3 -IN iN2 19 Re LOGIC ~ IN1 GROUND 1.00K0) 5 INO t. a2] Ail AO ~ 1] 2,3 4 6 ca . CHANNEL | + OL SELECT iy _L = -5.0V = Figure 1. Typical Application 6 MAXIMCMOS Video Multiplexer/Amplifier Typical Applications Figure 2 shows the connections for a unity-gain amplifier. Ri and R2 adjust the gain to be nominally 1.00V/V. R3 isa 75 ohm load resistor. If precise unity-gain is not needed, R1 and R2 can be omitted and -IN can be connected directly to Voyr. From MUX Vout Figure 2. Unity-Gain Connections Figure 3 shows how 64 channels can be multiplexed together. Eight MAX455s select 8 out of 64 channels, and a final MAX455 selects one of the 8 intermediate channels. The first sight MAX455s are connected as unity-gain amplifiers with 150 ohm load resistors. This results in a voltage gain of about 0.99V/V. The 150 ohm loads will also cause these unity-gain amplifiers to peak around 40MHz which tends to cancel the rolloff of the final amplifier running at a gain of 2V/V. The overall gain is adjusted by R1. The -3dB frequency is about 35MHz. load and the amplifier output. This minimizes signal peaking at high frequencies. As a rule, the resistor should be chosen such that the RC product is 10ns or longer. This scheme shouldnt be used if R is greater than 150 ohms (or C is less than 100pF). The amplifier can drive 100pF directly without an isolation resistor. The video amplifier is similar to a transconductance amplifier in that the output is a current proportional to the difference of the input voltage and the feedback voltage. Gm is about 0.5 mA/mV. The output impedance of the amplifier is around 1k ohms. This gives an unloaded voltage gain of, Gm x Ro = 500 V/V or about 54 cB. Video signals are often of one polarity, e.g., ranging fromO to +1V full scale. When amplifying these signals, phase distortion can be reduced by biasing the output stage of the video amplifier as shown in Figure 5. Here a signal is driven 0 to + 2V into a 150 ohm load. R2 provides 6.5 mA of drive to the load at mid scale (1V). The amplifier, instead of supplying 0 to 13mA, supplies amore symmetric +8mA which reduces phase distortion to about 1 de- gree at 4 MHz. Because of the amplifiers finite gain of 0.5mA/mV, the current from R2 introduces an offset voitage. Adding R1 compensates for this offset. R3 and R4 set the closed-loop gain of the amplifier. Care should be taken in laying out the printed circuit board connections to minimize cross-talk between channels. This can be augmented by using ground Figure 4 shows the amplifier driving acapacitiveload.The _tfaces between the signal paths. 27 ohm resistor provides isolation between the capacitive 63- I e2] 'N + 61J 60 9 37 = 7 NO 9a 4 4 4 IN7 76Q A2 At AO Xp XX INO 6.8pf* 7 hw7 ae 8 5 A2 Al AO -IN 4 Xe X4 Xy = . __ MSB of om 7 | Address A2 A1 AO Xo %1 % 1500 LSB of * Chosen to compensate for stray Input capacitance. Address = . Figure 3. Nine MAX455s Used to Multiplex 64 Channels. MAAIM S/P/E/ESPXVNMAX452/3/4/5 CMOS Video Multiplexer/Amplifier Power supply voltages should be maintained to within +5V + 5% of the nominal + 5.00V values for optimum per- : Rt formance. rom 150K Pe Vo =V, From MUX + Yo 'o = Yout/2 T 470 pF Figure 4. Isolating a Large Capacitive Load. JT MUX Your 270 L -IN S = RS pT 6.8pf* a 1.07kQ 75Q -IN R4 1kOQ *Chosen to compensate for stray Input capacitance. Ordering information (continued) Figure 5. Minimizing Phase Distortion PART TEMP. RANGE PACKAGE MAX454MJD. -85C to +125C 14 lead CERDIP MAX455CPP 0Cto + 70C 20 lead plastic DIP MAX455CWP 0C to + 70C 20 lead small-outline MAX455C/D 0Cto + 70C Dice MAX455EPP -40C to +85C 20 lead plastic DIP MAX455EJP -40C to +85C 20 lead CERDIP MAX455MJP -55C to +125C 20 lead CERDIP Chip Topographies +IN iN@4 IN3 IN2 5 ~ IN5 13 2lE m1 & > iN6 15 of o - N = el2 IN7 17 V+ 6 > ve 18 -IN 7 -IN 49 tr 20 1 2 3 Vout A2 Ai AO 67") .067 (1. 70mm)" i (1.70mm) Note: Connect Die MAX452C/D Substrate to V+. MAX455C/D 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. 8 Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 1996 Maxim Integrated Products Printed USA MAXIM is a registered trademark of Maxim Integrated Products.