19-0449; Rev 0; 4/88 General Description Maxims HI-508A and MAX358 are 8 channel single- ended (1 of 8) multiplexers with fault protection. Maxim's HI-509A and MAX359 are 4 channel differ- ential (2 of 8) multiplexers with fault protection. Using a series N-channel, P-channel, N-channel structure, these multiplexers provide significantly improved fault protection. If the power supplies to the Maxim fault-protected multiplexer are inadver- tently turned off while input voltages are still applied, all channels in the multiplexer are turned off, and only a few nanoamperes of leakage current will flow into the inputs. This protects not only the multiplexer and the circuitry driven by the multiplexer, but also protects the sensors or signal sources which drive the multiplexer. The Maxim series N-channel, P-channel, N-channel protection structure has two significant advantages over the simple current limiting protection scheme of the first generation fault protected multiplexers. First, the Maxim protection scheme limits fault currents to nanoamp leakage values rather than many milli- amperes. This prevents damage to sensors or other sensitive signal sources. Second, the Maxim fault- protected multiplexers can withstand a continuous +35V overvoltage, unlike the first generation which has a continuous overvoltage limitation of about +10V imposed by power dissipation considerations. All digital inputs have logic thresholds of 0.8V and 2.4V, ensuring both TTL and CMOS compatibility without requiring pullup resistors. Break-before- make operation is guaranteed. Power supply currents have been reduced and typical power dissipation is less than 2 milliwatts. Applications Data Acquisition Systems Industrial and Process Control Systems Avionics Test Equipment Signal Routing between Systems MA AALSVI Fault-Protected Analog Multiplexer Features @ Improved 2nd Source (See Maxim Advantage on 3rd and 5th page) @ All Switches Off with Power Supplies Off @ On Channel Turns OFF if Overvoltage Occurs @ Only Nanoamperes of Input Current under All Fault Conditions @ Latchup-proof Construction @ Operates from +4.5 to +18V Supplies @ All Digital Inputs are TTL and CMOS Compatible Ordering Information PART TEMP. RANGE PACKAGE MAX358CPE 0C to +75C 16 Lead Plastic DIP MAX358CWE 0C to +75C ~- 16 Lead Wide SO MAX358CJE 0C to +75C =: 16 Lead CERDIP MAX358EPE ~40C to +85C 16 Lead Plastic DIP MAX358EWE -40C to +85C 16 Lead Wide SO MAX358EJE -40C to +85C = 16 Lead CERDIP MAX358MJE -55C to +125C 16 Lead CERDIP MAX358C/D** 0C to +75C Dice MAX359CPE 0C to +75C = 16 Lead Plastic DIP MAX359CWE 0C to +75C ~=-16 Lead Wide SO MAX359CJE oC to +75C ~=16 Lead CERDIP MAX359EPE -40C to +85C 16 Lead Plastic DIP MAX359EWE -40C to +85C 16 Lead Wide SO MAX359EJE -40C to +85C 16 Lead CERDIP MAX359MJE -55C to +125C 16 Lead CERDIP MAX359C/D** 0C to +75C_ Dice (Ordering Information is continued on last page.) **The substrate may be allowed to float or be tied to V* (JI CMOS), Pin Configuration VW TOP VIEW WU Ay 1] 16 J Ay Ay an 15] A, ENABLE [2 MAKIM [5] Ap ENABLE [2] MAKIN [5] GND Vsuepy 2] MAX358 14] GND ~Veupey MAX359 113) *Vsuppiy WN A} esoea = F8I *Vsurnuy Wig A 5094 FS Me IN, 5] 12] IN, INo, 24 12) INog IN; [6] 171] IN, IN, (84 11) IN3p IN, 7] 10] IN; INay, C7 10] IN4g out [a] 5] IN out, [4 3] OUT, The Maxim Advantage" signifies an upgraded quality level. At no additional cost we offer a second-source device that is subject to the following. guaranteed performance over temperature along with tighter test specifications on many key parameters, and device enhancements. when needed, that result inimproved performance without changing the functionality. MAXUM Cail toll free 1-800-998-8800 for free samples or literature. Maxim Integrated Products 1 V60S/V80S-IH 6SE/8SEXVNMAX358/359, HI-5O8A/S509A Fault-Protected Analog Multiplexer ABSOLUTE MAXIMUM RATINGS Voltage between Supply Pins .......... 0... e eee eee eens +44V a +22V VT cere e ene n tener e nner nts -22V Digital Input Overvoltage: Ven Va { Vsupply(*) Suppl -) Analog Input Overvoltage with Multiplexer Power On: Vg { Vsuppiy*) Supply") cece ee cette ete eet nett ees Analog Input Overvoltage with Multiplexer Power Off: Vv (A) ccc cece cee eet ener eee e nee +35V V. Supply 8 tere) ES -35V Continuous Current, S orD .. 2.6.6... eee eee 20mA Peak Current, S or D (Pulsed at 1ms, 10% duty cycle max) .............--55- 40mA Power Dissipation (Note 1) (CERDIP) ............-...-- 1.28W Operating Temperature Range: MAX358/359M; HI-508A/S09A-2, -8 ..... . -55C to +125C MAX358/359C; HI-508A/509A-5 ..........-- - 0C to +76C MAX358/359E oe. ee eee ee -40C to +85C Storage Temperature Range ..........-.-..-5 -65C to +150C Note 1: Derate 12.8mW/C above T, = +75C 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: HI-508A/509A (See facing page for MAX358/359.) Supplies = +15V, -15V; Vay (Logic Level High) = +4.0V, Va, (Logic Level Low) = +0.8V (unless otherwise noted). -55C to +125C 0C to +75C PARAMETER SYMBOL CONDITIONS TEMP UNITS MIN TYP MAX | MIN TYP MAX STATIC . Vp = H10V, Ig = 100nA +25C 1.2 15 15 18 ON Resistance FDSION) | Vay = O.BV, Vay = 4V Full 15 18 1a 20 | Ke OFF Input Leakage \ Vg = #10V, Vp = +10V +25C 0.03 0.03 nA Current S(OFF) | Vey = 0.8V (Note 2) Full 50 50 Vp = H10V, Vg = +10V +25C 01 01 OFF Output Leakage lovore) | Vew = 0.8V HI-508A | Full 200 200 | nA (Note 2) HI-S09A Full 100 100 Vs(atL) = Vp = 10V (Note 2) +25C 041 01 oN channel Leakage loom | Van = Ven = 4V HI-508A | Full 200 200 | nA Vat = 0.8V HI-509A Full 100 100 Analog Signal Range Van Full -15 +15 -15 +15 Vv Differential, OFF Output Leakage Current loier (HI-509A only) Full 50 50 nA FAULT Output Leakage Current \ Vp = OV +25C 4.0 4.0 | nA (with Overvoltage) D(OFF) | Analog Overvoltage = +33V Full 2.0 | HA INPUT Input Low Threshold Va. | (Note 3) Full 0.8 os | ov Input High Threshold VaH Full 4.0 40 Input Leakage Va = 4V or OV Current (High or Low) "a (Note 4) Full 10 10 HA DYNAMIC Access Time ta +25C 0.5 1.0 05 1.0 us _ . 7 Ven = +8V, Vin = t10V Break-Before-Make Delay | ton-torr Ay, Ay, Az Strobed +25C 25 80 25 80 ns +25C 300 500 300 Enable Delay (ON) tonteN} Full 4000 4000 ns 425C 300 500 300 Enable Delay (OFF) torriEN) Full 4000 4000 ns Settling Time (0.1%) 1.2 1.2 (0.01%) tserr *25C 35 35 HS Note 2: Ten nanoamps is the practical lower limit for high speed measurement in the production test environment. Note 3: To drive from DTL/TTL Circuits, 1k pull-up resistors to +5.0V supply are recommended. Note 4: Digital input leakage is primarily due to the clamp diodes. Typical leakage is less than 1nA at +25C. 2 MAXIFault-Protected Analog Multiplexer 4 Only Nanoamps of Leakage Under Fault Conditions @ All Switches OFF With Power Supplies Off @ Channel Turns OFF When Overvoltage Occurs @ +4.5V to +18V Operation ABSOLUTE MAXIMUM RATINGS: this device conforms to the Absolute Maximum Ratings on adjacent page. ELECTRICAL CHARACTERISTICS: MAX358/359 (See facing page for HI-508A/S509A. ) Specifications below satisfy or exceed all tested parameters on adjacent page. @ TTL Compatible, No Pullups Required Significantly Reduced Power Consumption Supplies = +15V, -15V; Vay (Logic Level High) = +2.4V, Va, (Logic Level Low) = +0.8V (unless otherwise noted). 0C to +75C -55C to +125C and PARAMETER SYMBOL CONDITIONS TEMP 740C to +85C | UNITS MIN TYP MAX | MIN TYP MAX STATIC . Vp = t10V, Ig = 100uA +25C 1.2 15 1.5 1.8 ON Resistance TOSION) | Va, = O.8V, Van = 2.4V Full 18 20 | ke OFF Input Leakage \ Vg = 10V, Vp = F10V +25C 0.03 05 0.03 1.0 nA Current S(OFF) | Ven = 0.8V Full 50 50 Vp = 10V, Vg = F10V +25C 0.1 1.0 0.1 2.0 OFF Output Leakage lbcorr) | Ven = 0.8V MAX358 | Full 200 200 | nA Current (OFF) MAX359 Full 100 100 Veal) = Vp = 10V (Note 2) | +25C 0.1 2.0 0.1 5.0 oN Channel Leakage loon) [Van = Ven = 24V MAX358| Full 200 200 | nA Vac = 0.8V MAX359 | Full 100 100 Analog Signal Range Van {Note 1) Full -15 +15 -16 +15 Vv Differential, OFF Output Leakage Current loirr MAX359 only Full 50 50 nA FAULT Output Leakage Current \ Vp = OV (Note 2) +25C 4.0 4.0 nA (with Overvoltage) D(OFF) | Analog Overvoltage = +33V Full 2.0 BA Input Leakage Current Vin = +25V, Vo = +10V (with Overvoltage) 's(oFF) (Note 2) +25C 5.0 10 HA Input Leakage Current Vin = +25V, Ven = Vo = OV (w. Power Supplies Off) Is(orr) Ag = Ay = Az = OV or 5V +25C 2.0 5.0 HA INPUT Input Low Threshold VaL Full 0.8 0.8 Vv Input High Threshold Van Full 2.4 2.4 Vv Input Leakage Vy = 4V or OV Current (High or Low) uN (Note 4) Full 1.0 10 uA DYNAMIC Access Time ty (Figure 1) +25C. 0.5 1.0 0.5 1.0 us Break-Before-Make Delay _ Ven = +5, Vi = =10V (Figure 2) tonctorF | ao A,, A, Strobed *25C | 25 80 2 80 ns (Figure 3) +26C 300 500 300 Enable Delay (ON) tonien) Full 1000 4000 ns (Figure 3) +25C 300 500 300 Enable Delay (OFF) torF(EN) Full 1000 1000 ns Settling Time (0.1%) 1.2 1.2 (0.01%) tserr +25C 35 35 HS Note 1: When the analog signal exceeds +13.5V or -12V the blocking action of Maxims gate structure goes into operation. Only leakage currents flow and the channel on resistance rises to infinity. Note 2: The value shown is the steady state vaiue. The transient leakage is typically 104A. See detailed description. Note 3: Electrical characteristics, such as ON Resistance, will change when power supplies other than +15V are used. Note 4: Digital input leakage is primarily due to the clamp diodes. Typical leakage is less than 1nA at +25C. MAXIM 3 V60S/V80S-IH 6SE/8SEXVNMAX358/359, HI-508A/509A Fault-Protected Analog Multiplexer ELECTRICAL CHARACTERISTICS: HI-508A/509A (continued) Supplies = +15V, -15V; Vay (Logic Level High) = +4.0V, Va, (Logic Level Low) = +0.8V (unless otherwise noted). PARAMETER SYMBOL CONDITIONS TEMP BBVE to #128" ore 10 475C UNITS MIN TYP MAX | MIN TYP MAX DYNAMIC (continued) : Ven = 0.8V, Ry = 1k0, OFF Isolation (Note 5) OFFiso) | Cy = 15pF, V = 7Vams, +25C 50 68 50 68 dB f = 100kHz Capacitance. Csiorr) 25C 5 5 pF Grictawe | Cor ase fe |G S| Digital Input Capacitance Ca +25C 5 5 pF Capacitance Cosiorr) +25C O4 OA pF SUPPLY | Positive Supply Current r Ven Va = OV or 4V Full 0.5 2.0 05 2.0 mA Negative Supply Current Ven Va = OV or 4V Full 0.02 1.0 0.02 1.0 mA ] Note 5: Worst case isolation occurs on channel 4 due to proximity to the output pins. MAX358: Vay 3.0 ADDRESS HISOBA: Vay 4.0V AH DRIVE (Wj) he INy tov \ MAXI IN2 50 THRU ov vA ul MAX358 'INz 1 | Aa HI-508A INgf-O._ 10 = rN PROBE voy | o our OUTPUT A 500 ay GND | \ 90% = | -10y ~H 4b = Figure 1. Access Time vs. Logic Level (High) MAX358: Vay - 3.0V HISOBA: Van = 4.0 he _ IN iV , MAXIM ADDRESS vs ul maxasa NO ow DRIVE (Va) Ay *HISOBA Ne = EN OUTPUT 502 9 =) eno aut O Vout 24y 3 = I250F 50% 50% | kz 1 = = aa = ae = topEN SIMILAR CONNECTION FOR MAX359 ANO HI-509A Figure 2. Break Before Make Delay (topen) MAXIMFault-Protected Analog Multiplexer ELECTRICAL CHARACTERISTICS: MAX358/359 (continued) Supplies = +15V, -15V; Va), (Logic Level High) = +2.4V, Va, (Logic Level Low) = +0.8V (unless otherwise noted). 0C to +75C -55C to +125C and PARAMETER SYMBOL CONDITIONS TEMP -40C to +85C | UNITS MIN TYP MAX| MIN TYP MAX DYNAMIC (continued) Ven = 0.8V, Ry = 1k? OFF Isolation OF Fuso; | C. = 15PF. V = 7Vams: 425C | 50 68 50 68 dB f = 100kHz Channel Input 6 Capacitance Cs(orr) +25C s 5 pF Channel Output MAX358 25 25 i Capacitance Corry | MAX359 +25C 12 12 | pF Digital Input Capacitance Cp +25C 5 5 | pF Input to Output o Capacitance Coscorry +25C 0.1 0.4 | pF SUPPLY ses Ven = 0.8V, or 2.4V +25C 0.1 0.6 0.2 1.0 + EN , Positive Supply Current | All Vq = OV or 5V Full 03 07 os 610 | . - Ven = 0.8V or 2.4V +25C 0.01 0.1 0.01 0.1 Negative Supply Current | All Vy = OV or SV Full 002 0.2 0.02 o1 | | Power Supply Range for Vv (Note 5) +25c | +45 418 | 445 +18 Vv | Continuous Operation op ~ ~ Note 5: Electrical characteristics, such as ON Resistance, will change when power supplies other than |! 15V are used MAX358: Va 3.0V HISOBA: Van 4.0 Az ; ENABLE DRIVE Ne OV 50% #- -- - P MAXI IN? i } L At MAX358 tw -Oo_ \ \ Ww |_ Ao] "HI-S0BA = "NO = | I | y EN OUT i | 90 A GND L . | OUTPUT | ik aR I25pF | 1 | | 2 500 | | I \ 90% 4 = ( ! i SIMILAR CONNECTION FOR MAX359 AND HI-509A OV ANALOG SIGNAL fg v Al Ap MIAKIYI Tien] = MAx358 iM HI-508A aut yo 10k: -15V BV a Ap ve AY Ao MAXI LEN | MAX358 IN HI-508A out V ! - | Figure 5. Input Leakage Current (Overvoltage) MAAIM Figure 6. Input Leakage Current (with Power Supplies OFF) V60S/V80S-IH 6SE/8SEXVNMAX358/359, HI-5O8A/509A Fault-Protected Analog Multiplexer Typical Operating Characteristics INPUT LEAKAGE VS. OFF CHANNEL LEAKAGE OUTPUT LEAKAGE VS. INPUT VOLTAGE WITH CURRENT VS. INPUT OFF CHANNEL Vt=V-=0V VOLTAGE WITH OVERVOLTAGE WITH +15V SUPPLIES +15V SUPPLIES mA 100A 1A 104A OA 280uA AT +35V 1A ge tas 305uA AT +50V = 1OOpA WA s = * OPERATING a@ [ams ___ PERATING ait = soma RANGE Bima RANGE 7 5 2 = IA aon _" =z = 10pA Ina LA = 100A 100pA Pe | S 10pa 1OpA 1pA IpA 50-30 -10 OV +10 +30 +50 50-30-10 OV +10 #80 +50 -50 30-10 OV +10 +30 50 vin Vn Ros(on vs. INPUT VOLTAGE in | +5 POWER ako, SUPPLIES +10 POWER SUPPLIES = 3n +1BV = POWER S SUPPLIES = x0 Ika Iv -100 SV HBV HOV BV Vin ANALOG INPUT TRUTH TABLEMAX358 AND HI-508A TRUTH TABLEMAX359 AND HI-509A ON ON Ap Ay Ao EN SWITCH Ay Ao EN SWITCH xX x x 0 NONE Xx x 0 NONE 0 0 0 1 1 0 0 1 1 0 0 1 1 2 0 1 1 2 0 1 0 1 3 1 0 1 3 0 1 1 1 4 1 1 1 4 1 0 0 1 5 1 0 1 1 6 1 1 0 1 7 1 1 1 1 8 Couns gn NOTE: Logic O" = Va, = 0.8V, Logic "1" = Vay > 2.4V 6 MAXI/VIFault-Protected Analog Multiplexer +15 -Vsuep GND ~15V - +Vsupe +15V THERMOCOUPLE Ny out . STRAIN GAUGE IN? MAX420 - | 4-20mA LOOP 7 , TRANSMITTER Ns iv ma MAXIM | gy N MAX358 *Vsure IMs IN} 100k. ing Nz 10k. MAXKIWVI *TOV OUT N 3 GAIN REFERENCE Nr oa5084 kn ZERO REFERENCE IN Maxa5e Na ~Vsupp GND I Wn -15V = - Figure 7, Typical Data Acquistion Front End Typical Applications Figure 7 shows a typical data acquisition system using the MAX358 multiplexer. Since the multiplexer is driving a high impedance input, its error is a func- tion of its own resistance (Rpsion)) times the multi- plexer leakage current (Ipjon)) ySnd the amplifier bias current (Ipias): Verr = Rpsion) * (Ipony + Ieias (MAX420)) 1.5k (2nA + 30pA) 3.05uV maximum error In most cases, this error is low enough that pre- amplification of input signals is not needed, even with very low level signals, such as 40uV/C from type J thermocouples. In systems with fewer than 8 inputs, an unused channel can be connected to the system ground reference point for software zero correction. A second channel connected to the system voltage reference allows gain correction of the entire data acquisition system as well. A MAX 420 precision op-amp is connected as a pro- grammable gain amplifier, with gains ranging from 1 to 10,000. The guaranteed 5uV unadjusted offset of the MAX420 maintains high signal accuracy, while programmable gain allows the output signal level to be scaled to the optimum range for the remainder of MAXLWVI the data acquisition system, normally a Sample/Hold and A/D. Since the gain-changing multiplexer is not connected to the external sensors, it can be either a DG508A multiplexer or the fault protected MAX358. Input switching, however, must be done with a fault protected MAX358 multiplexer if it is to provide the level of protection and isolation required with most data acquisition inputs. Since external signal sources may continue to supply voltage when the multiplexer and system power are turned off, non-fault protected multiplexers, or even first-generation fault protected devices, will allow many milliamps of fault current to flow from outside sources into the multiplexer. The result could be damage to either the sensors or the multiplexer. A non-fault protected multiplexer will also allow input overvoltages to appear at its output, perhaps damaging Sample/Holds or A/Ds. Such input overdrives may also cause input-to-input shorts, allowing the high current output of one sensor to possibly damage another. The MAX358 eliminates all of the above problems since it not only limits its output voltage to safe levels, with or without power applied (+Vsyp and -Vgyp), but also turns all channels off when power is removed, drawing only sub-microamp fault currents from the inputs, and maintaining isolation between inputs for continuous overvoltages up to +35V. V60S/V80S-IH 6SE/8SEXVNMAX358/359, HI-SO8A/SO9A Fault-Protected Analog Multiplexer Detailed Description Fault Protection Circuitry Maxims HI-508A/509A and MAX358/359 are fully fault-protected for continuous input voltages up to +35V, whether or not the +Vsyp and -Vsyp power supplies are present. These devices use a series FET protection scheme which not only protects the multiplexer output from overvoltage, but also limits the input current to sub-microamp levels. This fault current is several orders of magnitude lower than the original manufacturer's HI-508A (several milliamps), which uses 1 to 2k protection resistors in series with parasitic diodes connected to +Vgyp and -Vsup. Figures 8 and 9 show how the series FET circuit protects against overvoltage conditions. When power is off, the gates of all three FETs are at ground. With a -25V input, N-channel FET Q1 is turned on by the +25V gate-to-source voltage. The P-channel device (Q2), however, has +25V Vag and is turned off, there- by preventing the input signal from reaching the output. If the input voltage is +25V, Q1 has a negative Ves, which turns it off. Similarly, only sub-microamp leakage currents can flow from the output back to the input, since any voltage will turn off either Q1 or Q2. Figure 10 shows the condition of an OFF channel with +Vsup and -Vsyp present. As with Figures 8 and 9, either an N-channel or a P-channel device will be off for any input voltage from -35V to +35V. The leakage current with negative overvoltages will imme- diately drop to a few nanoamps at 25C. For positive overvoltages that fault current will initially be 10 or 20uA, decaying over a few seconds to the nanoamp level. The time constant of this decay is caused by the discharge of stored charge from internal nodes and does not compromise the fault protection scheme. Figure 11 shows the condition of the ON channel with +Vsyp and -Vsyp present. With input voltages less than +10V, all three FETs are on and the input signal appears at the output. If the input voltage exceeds +Vgyp minus the N-channel threshold volt- age (VTn), then the N-channel FET will turn off. For voltages more negative than -Vsyup minus the P- channel threshold (Vrp), the P-channel device will turn off. Since Vj is typically 1.5V and VrTp is typically 3V, the multiplexers output swing is limited to about -12V to +13.5V with +15V supplies. -25V OVERVOLTAGE N-CHANNEL MOSFET | Is 1S TURNED ON & & & BECAUSE Vgg = +250 = = P-CHANNEL MOSFET 18 OFF IV +1BV-15V +25v FORCED ON COMMON -25V G Qe a OUTPUT OVERVOLTAGE LINE BY EXTERNAL N-CHANNEL MOSFET 1 TURNED ON , cum BECAUSE Vgs = *10V _isy FROM +15 FROM 5 DRIVERS orivens MOSFET IS OFF P-CHANNEL MOSFET 1S OFF Figure 8. -25V Overvoltage with Multiplexer Power OFF Figure 10. -25V Overvoitage on an OFF Channel with Multiplexer Power Supply ON +25V OVERVOLTAGE N-CHANNEL MOSFET IS TURNED OFF BECAUSE Ves = -25V Ft k -15V +15 -15V +25 Q_ 135V) Q2 Q3 13.5V OVERVOLTAGE OUTPUT N-CHANNEL MOSFET i = sf |S TURNED OFF GECAUSE Ves = -10V +15V FROM -15 FROM ORIVERS ORIVERS W-CHANNEL MOSFET 1S ON Figure 9. +25V Overvoltage with Multiplexer Power OFF Figure 11. +25V Overvoitage Input to the ON Channel MAAKIMFault-Protected Analog Multiplexer The Typical Characteristics graphs show typical leakage vs. input voltage curves. Although the max- imum rated overvoltage of these devices is +35V, the MAX358/359 typically has excellent performance up to +40V, providing additional margin for the unknown transients that exist in the real world. In summary, the MAX358/359 provides superior protection from all fault conditions, while using a standard, readily produced junction isolated CMOS process. Switching Characteristics and Charge Injection Table 1 shows typical charge injection levels vs. power supply voltages and analog input voltage. Note that since the channels are well matched, the differential charge injection for the MAX359/HI-509A is typically less than 5 picocoulombs. The charge injection that occurs during switching creates a voltage transient whose magnitude is inversely proportional to the capacitance on the multiplexer output. The channel-to-channel switching time is typically 600ns, with about 200ns of break before make delay. This 200ns break-before-make delay prevents the input-to-input short that would occur if two input channels were simultaneously connected to the out- put. In a typical data acquisition system such as Fig- ure 7, the dominant delay is not the switching time of the MAX358 multiplexer, but is the settling time of the following amplifiers and S/H. Another limiting factor is the RC time constant of the multiplexer Rosyon) plus the signal source impedance multiplied by the load capacitance on the output of the multiplexer. Even with low signal source impedances, 100pF of capacitance on the multiplexer output will approxi- mately double the settling time to 0.01% accuracy. Operation with Supply Voltages Other than +15V The main effect of supply voltages other than +15V is the reduction in output signal range. The MAX358 limits the output voltage to about 1.5V below +Vsuyp and about 3V above -Vsyp. In other words, the output swing is limited to +3.5V to -2V when operating from +5V. The typical characteristics graphs show typical Rpscon) for 15V, +10V, and +5V power supplies. Maxim tests and guarantees the MAX358/359 for operation from +4.5V to +18V supplies. The switching delays are increased by about a factor of 2 at +5V, but break-before-make action is preserved. The MAX358/9 can be operated with a single +9V to +22V supply, as well as asymmetrical power supplies such at +15V and -5V. The digital threshold will remain approximately 1.6V above the Ground pin, and the analog characteristics such as Rpson) are determined by the total voltage difference between +Vgup and -Vgyp. Connect -Vsup to OV when operat- ing with a +9V to +22V single supply. The MAX358 digital threshold is relatively independ- ent of the power supply voltages, going from a MAKLWVI Table 1A. MAX358 AND HI-508A CHARGE INJECTION Supply Voltage Analog Input Level Injected Charge +1.7V +100pC +5V ov +70pC -1.7V +45pC +5V +200pC +10V ov +130pC -5V +60pC +10V +300pC +15V ov +180pC -10V +50pC Test Conditions: C, = 1000pF on multiplexer output; the tabulated analog input level is applied to channel 1; channels 2 through 8 inputs are open circuited. EN = +5V, A, = Az = OV, Ag is toggled at 2kHz rate between OV and 3V. +100 picocoulombs of charge creates a+100mV step when injected into a 1000pF load capacitance. Table 1B. MAX359 AND HI-509A CHARGE INJECTION Injected Charge Supply Analog ee Voltage Input Level OutA Out B | Differential A-B +1.7V +105pC +107pC -2pC +5V ov +73pC +74pC -1pc -1.7V +48pC +50pC -2pC +5V +215pC +220pC -5pC 410V OV +1350C +139pC -4pC -5V +62pC +63pC -1pc +10V +325pC +330pC -5pC +15V ov +180pC +185pC -5pC -10V +55pC +55pC Oopc Test Conditions: C, = 1000pF on Out A and Out B; the tabulated analog input level is applied to inputs 1A and 1B; channels 2 through 4 are open circuited. EN = +5V, A, = OV, Agis toggled from OV to 3V at a 2kHz rate. typical 1.6V when +Vgup is 15V to 1.5V typical with a 5V +Vsyp. This means that Maxim HI-508/509A and MAX358/359 will operate with standard TTL logic levels, even with +5V power supplies. In all cases, the threshold of the ENable pin is the same as the other logic inputs. Digital interface Levels The typical digital threshold of both the address lines and the enable pin is 1.6V, with a temperature coefficient of about -3mV/C. This ensures compatibility with 0.8V to 2.4V TTL logic swings over the entire temperature range. The digital threshold is relatively independent of the supply voltages, moving from 1.6V typical to 1.5V typical as the power supplies are reduced from +15V to +5V. In all cases, the digital threshold is referenced to the Ground pin. The digital inputs can also be driven with CMOS logic V60S/V80S-IH '6SE/8SEXVNMAX358/359, HI-508A/S09A Fault-Protected Analog Multiplexer levels swinging from either +Vsyp to -Vgyp or from +Vsyp to Ground. The digital input current is just a few nanoamps of leakage at all input voltage levels, with a guaranteed maximum of 1A. The digital inputs are protected from ESD by a 30V zener diode between the input and +Vsyp, and can be driven +6V beyond the supplies without drawing excessive current. Operation as a Demultiplexer The MAX358/9 will function as a demultiplexer, where the input is applied to the Output pin, and the Input pins are used as outputs. The MAX358/9 provides both break-before-make action and full fault protection when operated as a demultiplexer, unlike earlier generations of fault protected multiplexers. Channel-to-Channel Crosstalk, Off Isolation and Digital Feedthrough At DC and low frequencies the channel-to-channel crosstalk is caused by variations in output leakage currents as the off channel input voltages are varied. The MAX358 output leakage varies only a few picoamps as all 7 off inputs are toggled from -10V to + 10V. The output voltage change depends on the impedance level at the MAX358 output, which is Rpg(on) plus the input signal source resistance in most cases since the load driven by the MAX358 is usually a high impedance. For a signal source impedance of 10k or lower, the DC crosstalk exceeds 120dB. Table 2 shows typical AC crosstalk and off isolation performance. Digital feedthrough is masked by the analog charge injection when the output is enabled. When the output is disabled, the digital feedthrough is virtually unmeasureable, since the digital pins are physically isolated from the analog section by the Ground and -Vsup pins. The groundplane formed by these lines is continued onto the MAX358/9 die to provide over 100dB isolation between the digital and analog sections. Table 2A. TYPICAL OFF ISOLATION REJECTION RATIO Frequency 100kHz 500kHz 1IMHz One Channel Driven 74dB 72dB 66dB All Channels Driven 64dB 48dB 44dB Test Conditions: Vjy = 20Vp, py at the tabulated frequency, R, = 15k between OUT and ground, EN = OV. 20VpK-pK OIRR = 20 Log --_ OUT (PK-PK) Table 2B. TYPICAL CROSSTALK REJECTION RATIO Frequency 100kHz 500kHz 1MHz R, = 1.5k 70dB 68dB 64dB R_ = 10k 62dB 46dB 42dB Test Conditions: Specified R, connected from OUT to ground, EN = +5V, Ay = A, = Ay = +5V (Channel 1 selected). 20Vp,_p, at the tabulated frequency is applied to Channel 2. All other channels are open circuited. Similar crosstalk rejection can be observed between any two channels. MAXAL/VI 10 Ordering Information (continued) Fault-Protected Analog Multiplexer PART TEMP. RANGE PACKAGE H11-0508A-2 -55C to +125C 16 Lead CERDIP H11-0508A-5* 0C to +75C 16 Lead CERDIP HI3-0508A-5* 0C to +75C = 16 Lead Plastic DIP HI1-0509A-2 -55C to +125C 16 Lead CERDIP H11-0509A-5* 0C to +75C 16 Lead CERDIP HI3-0509A-5* 0C to +75C = 16 Lead Plastic DIP Maxim burns in all devices at 150C. Maxim's -5 device is therefore equivalent to the original manufacturer's -7 product. MAXIM Chip Topographies MAX358 0139" _| HI-508A (3.531mm} IN, ~~~ IN, IN, oo INg ! IN IN ; 0.158" IN, IN, (40tmm) Vsupeer ~ Vsuprty GND R21. ADENABLE Note: Connect substrate to +Vgypp_y or Leave It Floating MAX359 0.139" HI-509A (3531mm) af IN IN. = * 0158" Nig - Ny (401mm) Vsupeu] \ GND Al AO ENABLE Note: Connect substrate to +Vguypp_y or Leave It Floating 11 V60S/V80S-IH 6SE/8SEXVN