19-1902; Rev 1; 8/94 High-Voltage, Fault-Protected Analog Multiplexers ____________________________Features The MAX378 8-channel single-ended (1-of-8) multiplexer and the MAX379 4-channel differential (2-of-8) multiplexer use a series N-channel/P-channel/N-channel structure to provide significant fault protection. If the power supplies to the MAX378/MAX379 are inadvertently turned off while input voltages are still applied, all channels in the muxes are turned off, and only a few nanoamperes of leakage current will flow into the inputs. This protects not only the MAX378/MAX379 and the circuitry they drive, but also the sensors or signal sources that drive the muxes. The series N-channel/P-channel/N-channel protection structure has two significant advantages over the simple current-limiting protection scheme of the industry's firstgeneration fault-protected muxes. First, the Maxim protection scheme limits fault currents to nanoamp leakage values rather than many milliamperes. This prevents damage to sensors or other sensitive signal sources. Second, the MAX378/MAX379 fault-protected muxes can withstand a continuous 60V input, unlike the first generation, which had a continuous 35V input limitation 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 pull-up resistors. Break-before-make operation is guaranteed. Power dissipation is less than 2mW. ________________________Applications Data Acquisition Systems Industrial and Process Control Systems Avionics Test Equipment Signal Routing Between Systems Fault Input Voltage 75V with Power Supplies Off Fault Input Voltage 60V with 15V Power Supplies All Switches Off with Power Supplies Off On Channel Turns OFF if Overvoltage Occurs on Input or Output Only Nanoamperes of Input Current Under All Fault Conditions No Increase in Supply Currents Due to Fault Conditions Latchup-Proof Construction Operates from 4.5V to 18V Supplies All Digital Inputs are TTL and CMOS Compatible Low-Power Monolithic CMOS Design ______________Ordering Information TEMP. RANGE PART PIN-PACKAGE 0C to +70C MAX378CPE 16 Plastic DIP MAX378CWG 0C to +70C 24 Wide SO MAX378CJE 0C to +70C 16 CERDIP MAX378C/D 0C to +70C Dice** MAX378EPE -40C to +85C 16 Plastic DIP MAX378EWG -40C to +85C 24 Wide SO MAX378EJE -40C to +85C 16 CERDIP MAX378MJE -55C to +125C 16 CERDIP MAX378MLP -55C to +125C 20 LCC* Ordering Information continued at end of data sheet. * Contact factory for availability. **The substrate may be allowed to float or be tied to V+ (JI CMOS). __________________________________________________________Pin Configurations TOP VIEW A0 1 16 A1 A0 1 16 A1 EN 2 15 A2 EN 2 15 GND V- 3 14 GND V- 3 IN1 4 MAX378 14 V+ MAX379 13 V+ IN1A 4 IN2 5 12 IN5 IN2A 5 12 IN2B IN3 6 11 IN6 IN3A 6 11 IN3B IN4 7 10 IN7 IN4A 7 10 IN4B OUT 8 9 IN8 DIP Pin Configurations continued at end of data sheet. OUTA 8 13 IN1B 9 OUTB DIP ________________________________________________________________ Maxim Integrated Products Call toll free 1-800-998-8800 for free samples or literature. 1 MAX378/MAX379 _______________General Description MAX378/MAX379 High-Voltage, Fault-Protected Analog Multiplexers ABSOLUTE MAXIMUM RATINGS Voltage between Supply Pins ..............................................+44V V+ to Ground ...................................................................+22V V- to Ground......................................................................-22V Digital Input Overvoltage: V+......................................................................+4V VEN, VA V- ........................................................................-4V Analog Input with Multiplexer Power On..............................65V Recommended V+ .....................................+15V Power Supplies V- .......................................-15V Analog Input with Multiplexer Power Off..............................80V { { } Continuous Current, IN or OUT...........................................20mA Peak Current, IN or OUT (Pulsed at 1ms, 10% duty cycle max) ............................40mA Power Dissipation (Note 1) (CERDIP) ................................1.28W Operating Temperature Range: MAX378/379C .....................................................0C to +70C MAX378/379E ..................................................-40C to +85C MAX378/379M ...............................................-55C to +125C Storage Temperature Range .............................-65C to +150C Note 1: Derate 12.8mW/C above TA = +75C 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+ = +15V, V- = -15V; VAH (Logic Level High) = +2.4V, VAL (Logic Level Low) = +0.8V, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS TEMP -55C to +125C 0C to +70C and -40C to +85C MIN TYP MAX MIN TYP MAX UNITS STATIC ON Resistance rDS(ON) OFF Input Leakage Current IIN(OFF) OFF Output Leakage Current ON Channel Leakage Current Analog Signal Range Differential OFF Output Leakage Current IOUT(OFF) IOUT(ON) VOUT = 10V, IIN = 100A VAL = 0.8V, VAH = 2.4V VIN = 10V, VOUT = 10V VEN = 0.8V (Note 6) +25C 2.0 3.0 2.0 3.5 Full 3.0 4.0 3.0 4.0 -0.5 0.03 0.5 -1.0 0.03 1.0 -50 50 -50 50 VOUT = 10V, VIN = 10V VEN = 0.8V MAX378 (Note 6) MAX379 +25C -1.0 1.0 -2.0 Full -200 200 -200 200 Full -100 100 -100 100 VIN(ALL) = VOUT = 10V VAH = VEN = 2.4V MAX378 VAL = 0.8V (Note 5) MAX379 +25C -10 10 -20 Full -600 600 -600 600 Full -300 300 -300 300 +25C Full 0.1 0.1 0.1 0.1 k nA 2.0 nA 20 nA VAN (Note 2) Full -15 +15 -15 +15 V IDIFF MAX379 only (Note 6) Full -50 50 -50 50 nA FAULT Output Leakage Current (with Input Overvoltage) IOUT(OFF) VOUT = 0V, VIN = 60V (Notes 3, 4) Input Leakage Current (with Overvoltage) IIN(OFF) VIN = 60V, VOUT = 10V (Notes 3, 4) Input Leakage Current (with Power Supplies Off) IIN(OFF) VIN = 75V, VEN = VOUT = 0V A0 = A1 = A2 = 0V or 5V +25C 20 20 nA Full 10 20 A +25C 25 40 A +25C 10 20 A 0.8 V CONTROL Input Low Threshold VAL (Note 4) Full Input High Threshold VAH (Note 4) Full 2.4 VA = 5V or 0V (Note 5) Full -1.0 Input Leakage Current (High or Low) 2 IA 0.8 2.4 1.0 -1.0 _______________________________________________________________________________________ V 1.0 A High-Voltage, Fault-Protected Analog Multiplexers (V+ = +15V, V- = -15V; VAH (Logic Level High) = +2.4V, VAL (Logic Level Low) = +0.8V, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS TEMP -55C to +125C 0C to +70C and -40C to +85C MIN TYP MAX MIN TYP MAX 0.5 0.5 UNITS DYNAMIC Access Time tA Figure 1 +25C tON-tOFF VEN = +5V, VIN = 10V A0, A1, A2 strobed +25C Enable Delay (ON) tON(EN) Figure 3 Enable Delay (OFF) tOFF(EN) Figure 3 Settling Time (0.1%) (0.01%) tSETT Break-Before-Make Delay (Figure 2) "OFF Isolation" OFF(ISO) Channel Input Capacitance CIN(OFF) Channel Output Capacitance Digital Input Capacitance Input to Output Capacitance 25 +25C 200 400 Full +25C 300 Full 25 50 1.0 200 750 400 1000 1500 500 300 1000 1.2 1.2 3.5 3.5 68 50 s ns 1000 1000 +25C VEN = 0.8V, RL = 1k, CL = 15pF +25C V = 7VRMS, f = 100kHz 1.0 ns ns s 68 dB pF +25C 5 5 MAX378 +25C MAX379 25 25 12 12 CA +25C 5 5 pF CDS(OFF) +25C 0.1 0.1 pF COUT(OFF) pF SUPPLY Positive Supply Current I+ VEN = 0.8V or 2.4V All VA = 0V or 5V +25C 0.1 0.6 0.2 1.0 Full 0.3 0.7 0.5 1.0 Negative Supply Current I- VEN = 0.8V or 2.4V All VA = 0V or 5V +25C 0.01 0.1 0.01 0.1 Full 0.02 0.2 0.02 0.1 Power-Supply Range for Continuous Operation VOP (Note 7) +25C 4.5 18 4.5 mA mA 18 V Note 2: When the analog signal exceeds +13.5V or -12V, the blocking action of Maxim's gate structure goes into operation. Only leakage currents flow and the channel ON resistance rises to infinity. Note 3: The value shown is the steady-state value. The transient leakage is typically 50A. See Detailed Description. Note 4: Guaranteed by other static parameters. Note 5: Digital input leakage is primarily due to the clamp diodes. Typical leakage is less than 1nA at +25C. Note 6: Leakage currents not tested at TA = cold temp. Note 7: Electrical characteristics, such as ON Resistance, will change when power supplies other than 15V are used. _______________________________________________________________________________________ 3 MAX378/MAX379 ELECTRICAL CHARACTERISTICS (continued) __________________________________________Typical Operating Characteristics OFF CHANNEL LEAKAGE CURRENT vs. INPUT VOLTAGE WITH 15V SUPPLIES 10n 1n 1n OPERATING RANGE +80V 100p -80V 100p 10n -60V OPERATING RANGE 100n 10p -100 0 -50 50 MAX378-3 1n 100p OPERATING RANGE +60V 100n IOUT(OFF) (A) 1 1 +60V 10 10n MAX378-2 10 IIN(OFF) (A) INPUT CURRENT (A) 100 MAX378-1 1m 100 OUTPUT LEAKAGE CURRENT vs. OFF CHANNEL OVERVOLTAGE WITH 15V SUPPLIES -60V INPUT LEAKAGE vs. INPUT VOLTAGE WITH V+ = V- = 0V 10p 10p 1p -120 100 0 -60 VIN (V) 60 1p -120 120 0 -60 VIN (V) 60 VIN(OFF) (V) DRAIN-SOURCE ON-RESISTANCE vs. ANALOG INPUT VOLTAGE +3.5V MAX3784 7 +4V 6 +13V 5V SUPPLIES RDS(ON) (k) 5 4 +13V 3 15V SUPPLIES 2 NOTE: Typical RDS(ON) match @ +10V Analog in (15V supplies) = 2% for lowest to highest R DS(ON) channel; @ -10V Analog in, match = 3%. MAX378: VAH = 3.0V 1 0 -15 -10 -5 0 5 10 15 20 ANALOG INPUT (V) A2 ADDRESS DRIVE (VA) IN1 IN2 50% A1 0V VA +10V OUTPUT A +VAH 50 10V MAX378 IN2-IN7 A0 IN8 EN OUT MAX378/MAX379 High-Voltage, Fault-Protected Analog Multiplexers GND 90% PROBE 10V -10V 10M 14pF tA Figure 1. Access Time vs. Logic Level (High) 4 _______________________________________________________________________________________ 120 High-Voltage, Fault-Protected Analog Multiplexers A1 VA 2.4V 50% 50% +5V IN1 IN2 ADDRESS DRIVE (VA) 0V MAX378/MAX379 A2 MAX358: VAH = 3.0V 50 OUTPUT MAX378* IN2-IN7 A0 IN8 EN OUT VOUT GND 12.5pF 1k tOPEN *SIMILAR CONNECTION FOR MAX379 Figure 2. Break-Before-Make Delay (tOPEN) MAX378: VAH = 3.0V A2 IN1 A1 MAX378* IN2-IN7 +10V ENABLE DRIVE 50% 0V A0 90% OUT EN VA OUTPUT GND 12.5pF 1k 50 90% tON(EN) tOFF(EN) *SIMILAR CONNECTION FOR MAX379 Figure 3. Enable Delay (tON(EN), tOFF(EN)) +5V +15V A0 0V V- A0 +5V or 0V A1 A2 EN I MAX378 A1 A2 EN I OUT IN1 V- MAX378 OUT IN1 IN8 60V V- V 10V ANALOG SIGNAL GND -15V Figure 4. Input Leakage Current (Overvoltage) 10k 75V V- GND 10k 0V Figure 5. Input Leakage Current (with Power Supplies OFF) _______________________________________________________________________________________ 5 MAX378/MAX379 High-Voltage, Fault-Protected Analog Multiplexers Truth Table--MAX378 Truth Table--MAX379 A2 A1 A0 EN ON SWITCH X 0 0 0 0 1 1 1 1 X 0 0 1 1 0 0 1 1 X 0 1 0 1 0 1 0 1 0 1 1 1 1 1 1 1 1 NONE 1 2 3 4 5 6 7 8 A1 A0 EN ON SWITCH X 0 0 1 1 X 0 1 0 1 0 1 1 1 1 NONE 1 2 3 4 Note: Logic "0" = VAL 0.8V, Logic "1" = VAH 2.4V +15V THERMOCOUPLE IN1 STRAIN GUAGE IN2 4-20mA LOOP TRANSMITTER IN3 V+ +15V OUT MAX420 -15V +15V IN4 V+ IN5 IN1 IN6 +10V GAIN REFERENCE IN7 ZERO REFERENCE IN8 1M MAX378 100k IN2 OUT V- GND -15V DG508A MAX358 OR MAX378 10k IN3 IN4 1k IN5 V- GND 111 -15V Figure 6. Typical Data Acquisition Front End _______________Typical Applications Figure 6 shows a typical data acquisition system using the MAX378 multiplexer. Since the multiplexer is driving a high-impedance input, its error is a function of its own resistance (RDS(ON)) times the multiplexer leakage current (IOUT(ON)) and the amplifier bias current (IBIAS): VERR = RDS(ON) x (IOUT(ON) + IBIAS (MAX420)) = 2.0k x (2nA + 30pA) = 18.0V maximum error In most cases, this error is low enough that preamplification of input signals is not needed, even with very low-level signals such as 40V/C from type J thermocouples. 6 In systems with fewer than eight 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 MAX420 precision op amp is connected as a programmable-gain amplifier, with gains ranging from 1 to 10,000. The guaranteed 5V 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 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 or MAX378. _______________________________________________________________________________________ High-Voltage, Fault-Protected Analog Multiplexers +60V OVERVOLTAGE N-CHANNEL MOSFET IS TURNED OFF BECAUSE VGS = -60V Q2 Q1 S Q3 D S D Fault Protection Circuitry -15V +15V -60V OVERVOLTAGE -60V Q2 Q1 N-CHANNEL MOSFET IS TURNED OFF BECAUSE VGS = +45V Q1 S N-CHANNEL MOSFET IS TURNED ON BECAUSE VGS = +60V D G -60V Q2 D S G Q3 D S G P-CHANNEL MOSFET IS OFF Figure 7. -60V Overvoltage with Multiplexer Power OFF +15V FROM DRIVERS -15V FROM DRIVERS -15V +60V FORCED ON COMMON OUTPUT LINE BY EXTERNAL CIRCUITRY Q3 N-CHANNEL MOSFET IS OFF P-CHANNEL MOSFET IS OFF Figure 9. -60V Overvoltage on an OFF Channel with Multiplexer Power Supply ON -15V -60V OVERVOLTAGE G Figure 8. +60V Overvoltage with Multiplexer Power OFF _______________Detailed Description The MAX378/MAX379 are fully fault protected for continuous input voltages up to 60V, whether or not the V+ and V- power supplies are present. These devices use a "series FET" switching scheme which not only protects the multiplexer output from overvoltage, but also limits the input current to sub-microamp levels. Figures 7 and 8 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 -60V input, N-channel FET Q1 is turned on by the +60V gate- D S G G MAX378/MAX379 Input switching, however, must be done with a faultprotected MAX378 multiplexer, 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. This could result in damage to either the sensors or the multiplexer. A nonfault-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 MAX378 eliminates all of the above problems. It not only limits its output voltage to safe levels, with or without power applied (V+ and V-), but also turns all channels off when power is removed. This allows it to draw only sub-microamp fault currents from the inputs, and maintain isolation between inputs for continuous input levels up to 75V with power supplies off. +60V OVERVOLTAGE N-CHANNEL MOSFET IS TURNED ON BECAUSE VGS = -45V Q1 +15V +13.5V Q2 -15V Q3 +13.5V OUTPUT VTN = +1.5V +15V FROM DRIVERS -15V FROM DRIVERS N-CHANNEL MOSFET IS ON Figure 10. +60V Overvoltage Input to the ON Channel _______________________________________________________________________________________ 7 MAX378/MAX379 High-Voltage, Fault-Protected Analog Multiplexers to-source voltage. The P-channel device (Q2), however, has +60V VGS and is turned off, thereby preventing the input signal from reaching the output. If the input voltage is +60V, Q1 has a negative VGS, 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 9 shows the condition of an OFF channel with V+ and V- present. As with Figures 7 and 8, either an N-channel or a P-channel device will be off for any input voltage from -60V to +60V. The leakage current with negative overvoltages will immediately drop to a few nanoamps at +25C. For positive overvoltages, that fault current will initially be 40A or 50A, 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 10 shows the condition of the ON channel with V+ and V- 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 V+ minus the Nchannel threshold voltage (VTN), then the N-channel FET will turn off. For voltages more negative than Vminus the P-channel threshold (VTP), the P-channel device will turn off. Since VTN is typically 1.5V and VTP is typically 3V, the multiplexer's output swing is limited to about -12V to +13.5V with 15V supplies. The Typical Operating Characteristics graphs show typical leakage vs. input voltage curves. Although the maximum rated input of these devices is 65V, the MAX378/MAX379 typically have excellent performance up to 75V, providing additional margin for the unknown transients that exist in the real world. In summary, the MAX378/MAX379 provide 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 MAX379 is typically less than 5pC. 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 simultaneous8 ly connected to the output. In a typical data acquisition system, such as in Figure 6, the dominant delay is not the switching time of the MAX378 multiplexer, but is the settling time of the following amplifiers and S/H. Another limiting factor is the RC time constant of the multiplexer RDS(ON) 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 approximately double the settling time to 0.01% accuracy. Operation with Supply Voltage Other than 15V The main effect of supply voltages other than 15V is the reduction in output signal range. The MAX378 limits the output voltage to about 1.5V below V+ and about 3V above V-. In other words, the output swing is limited to +3.5V to -2V when operating from 5V. The Typical Operating Characteristics graphs show typical RDS(ON), for 15V, 10V, and 5V power supplies. Maxim tests and guarantees the MAX378/MAX379 for operation from 4.5V to 18V supplies. The switching delays are increased by about a factor of 2 at 5V, but breakbefore-make action is preserved. The MAX378/MAX379 can be operated with a single +9V to +22V supply, as well as asymmetrical power supplies such as +15V and -5V. The digital threshold will remain approximately 1.6V above GND and the analog characteristics such as RDS(ON) are determined by the total voltage difference between V+ and V-. Connect V- to 0V when operating with a +9V to +22V single supply. This means that the MAX378/MAX379 will operate with standard TTL-logic levels, even with 5V power supplies. In all cases, the threshold of the EN pin is the same as the other logic inputs. Table 1a. MAX378 Charge Injection Supply Voltage Analog Input Level Injected Charge 5V +1.7V 0V -1.7V +100pC +70pC +45pC 10V +5V 0V -5V +200pC +130pC +60pC 15V +10V 0V -10V +500pC +180pC +50pC Test Conditions: CL = 1000pF on multiplexer output; the tabulated analog input level is applied to channel 1; channels 2 through 8 are open circuited. EN = +5V, A1 = A2 = 0V, A0 is toggled at 2kHz rate between 0V and 3V. +100pC of charge creates a +100mV step when injected into a 1000pF load capacitance. _______________________________________________________________________________________ High-Voltage, Fault-Protected Analog Multiplexers Injected Charge Supply Voltage Analog Input Level Out A Out B Differential A-B 5V +1.7V 0V -1.7V +105pC +73pC +48pC +107pC +74pC +50pC -2pC -1pC -2pC 10V +5V 0V -5V +215pC +135pC +62pC +220pC +139pC +63pC -5pC -4pC -1pC 15V +10V 0V -10V +525pC +180pC +55pC +530pC +185pC +55pC -5pC -5pC 0pC Test Conditions: CL = 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, A1 = 0V, A0 is toggled from 0V to 3V at a 2kHz rate. rents as the off-channel input voltages are varied. The MAX378 output leakage varies only a few picoamps as all seven off inputs are toggled from -10V to +10V. The output voltage change depends on the impedance level at the MAX378 output, which is RDS(ON) plus the input signal source resistance in most cases, since the load driven by the MAX378 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 unmeasurable, since the digital pins are physically isolated from the analog section by the GND and V- pins. The ground plane formed by these lines is continued onto the MAX378/MAX379 die to provide over 100dB isolation between the digital and analog sections. Digital Interface Levels The typical digital threshold of both the address lines and the EN 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 GND. The digital inputs can also be driven with CMOS-logic levels swinging from either V+ to V- or from V+ to GND. 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 V+, and can be driven 4V beyond the supplies without drawing excessive current. Operation as a Demultiplexer The MAX378/MAX379 will function as a demultiplexer, where the input is applied to the OUT pin, and the input pins are used as outputs. The MAX378/MAX379 provide 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, channel-to-channel crosstalk is caused by variations in output leakage cur- Table 2a. Typical Off-Isolation Rejection Ratio Frequency 100kHz 500kHz 1MHz One Channel Driven 74dB 72dB 66dB All Channels Driven 64dB 48dB 44dB Test Conditions: V IN = 20VP-P at the tabulated frequency, RL = 1.5k between OUT and GND, EN = 0V. 20VP-P OIRR = 20 Log ____________ VOUT (P-P) Table 2b. Typical Crosstalk Rejection Ratio Frequency 100kHz 500kHz 1MHz FL = 1.5k 70dB 68dB 64dB RL = 10k 62dB 46dB 42dB Test Conditions: Specified RL connected from OUT to GND, EN = +5V, A0 = A1 = A2 = +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. _______________________________________________________________________________________ 9 MAX378/MAX379 Table 1b. MAX379 Charge Injection _____________________________________________Pin Configurations (continued) TOP VIEW A0 1 24 A1 A0 1 24 A1 EN 2 23 A2 EN 2 23 N.C. N.C. 3 22 GND N.C. 3 22 GND N.C. 4 21 N.C. N.C. 4 21 N.C. MAX378 V- 5 MAX379 20 V+ V- 5 IN1 6 19 IN5 IN1A 6 19 IN1B IN2 7 18 IN6 IN2A 7 18 IN2B IN3 8 17 N.C. IN3A 8 17 IN3B 16 IN7 IN4A 9 16 IN4B N.C. 10 15 N.C. N.C. 10 15 N.C. N.C. 11 14 N.C. N.C. 11 14 N.C. OUT 12 13 IN8 OUTA 12 13 OUTB V- 4 18 GND 19 GND 20 A1 1 N.C. V- 4 18 V+ 17 V+ IN1A 5 16 N.C. N.C. 6 IN2 7 15 IN5 IN2A 7 15 IN2B IN3 8 14 IN6 IN3A 8 14 IN3B LCC 16 N.C. IN4B 13 OUTB 12 N.C. 11 MAX379 9 IN7 13 IN8 12 N.C. 11 IN4 9 MAX378 17 IN1B IN4A N.C. 6 OUTA 10 IN1 5 2 A0 3 EN 19 A2 SO 20 A1 1 N.C. 2 A0 3 EN SO 10 20 V+ IN4 9 OUT 10 MAX378/MAX379 High-Voltage, Fault-Protected Analog Multiplexers LCC ______________________________________________________________________________________ High-Voltage, Fault-Protected Analog Multiplexers PART TEMP. RANGE _________________Chip Topographies PIN-PACKAGE MAX379CPE 0C to +70C 16 Plastic DIP MAX379CWG MAX379CJE MAX379C/D MAX379EPE MAX379EWG MAX379EJE MAX379MJE MAX379MLP 0C to +70C 0C to +70C 0C to +70C -40C to +85C -40C to +85C -40C to +85C -55C to +125C -55C to +125C 24 Wide SO 16 CERDIP Dice** 16 Plastic DIP 24 Wide SO 16 CERDIP 16 CERDIP 20 LCC* * Contact factory for availability. **The substrate may be allowed to float or be tied to V+ (JI CMOS). MAX378 IN8 OUT IN4 IN7 IN7 IN3 0.229" (5.816mm) IN6 IN2 IN5 V+ IN1 V- GND A2 A1 A0 EN 0.151" (3.835mm) NOTE: Connect substrate to V+ or leave it floating. MAX379 OUTB OUTA IN4A IN4B IN3B IN3A 0.229" (5.816mm) IN2B IN2A IN1B V+ IN1A V- GND A1 A0 EN 0.151" (3.835mm) NOTE: Connect substrate to V+ or leave it floating. ______________________________________________________________________________________ 11 MAX378/MAX379 _Ordering Information (continued) MAX378/MAX379 High-Voltage, Fault-Protected Analog Multiplexers ________________________________________________________Package Information DIM D 0- 8 A e B 0.101mm 0.004in. A1 C L A A1 B C E e H L INCHES MAX MIN 0.104 0.093 0.012 0.004 0.019 0.014 0.013 0.009 0.299 0.291 0.050 0.419 0.394 0.050 0.016 DIM PINS E Wide SO SMALL-OUTLINE PACKAGE (0.300 in.) H D D D D D 16 18 20 24 28 INCHES MIN MAX 0.398 0.413 0.447 0.463 0.496 0.512 0.598 0.614 0.697 0.713 MILLIMETERS MIN MAX 2.35 2.65 0.10 0.30 0.35 0.49 0.23 0.32 7.40 7.60 1.27 10.00 10.65 0.40 1.27 MILLIMETERS MIN MAX 10.10 10.50 11.35 11.75 12.60 13.00 15.20 15.60 17.70 18.10 21-0042A DIM D1 A A1 A2 A3 B B1 C D D1 E E1 e eA eB L E E1 D A3 A A2 L A1 INCHES MAX MIN 0.200 - - 0.015 0.150 0.125 0.080 0.055 0.022 0.016 0.065 0.050 0.012 0.008 0.765 0.745 0.030 0.005 0.325 0.300 0.280 0.240 0.100 BSC 0.300 BSC 0.400 - 0.150 0.115 15 0 MILLIMETERS MIN MAX - 5.08 0.38 - 3.18 3.81 1.40 2.03 0.41 0.56 1.27 1.65 0.20 0.30 18.92 19.43 0.13 0.76 7.62 8.26 6.10 7.11 2.54 BSC 7.62 BSC - 10.16 2.92 3.81 0 15 21-587A C e B1 B eA 16-PIN PLASTIC DUAL-IN-LINE PACKAGE eB 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. 12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600 (c) 1994 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.