MAX379CPE+ ,8-Channel, High-Voltage, Fault-Protected MultiplexersFeatures' Fault Input Voltage ±75V with Power Supplies OffThe MAX378 8-channel single-ended (1-of-8 ..
MAX379CWG ,High-Voltage, Fault-Protected Analog MultiplexersGeneral Description ________
MAX379CWG+ ,8-Channel, High-Voltage, Fault-Protected MultiplexersApplicationsMAX378MJE -55°C to +125°C 16 CERDIPData Acquisition SystemsMAX378MLP -55°C to +125°C 20 ..
MAX379EWG+ ,8-Channel, High-Voltage, Fault-Protected MultiplexersELECTRICAL CHARACTERISTICS (continued)(V+ = +15V, V- = -15V; V (Logic Level High) = +2.4V, V (Logic ..
MAX3800UHJ ,3.2Gbps Adaptive Equalizer and Cable DriverELECTRICAL CHARACTERISTICS(V = +3.14V to +3.46V, T = 0°C to +85°C. Typical values are at V = +3.3V ..
MAX3800UHJ+ ,3.2Gbps Adaptive Equalizer and Cable DriverELECTRICAL CHARACTERISTICS(V = +3.14V to +3.46V, T = 0°C to +85°C. Typical values are at V = +3.3V ..
MAX7381AXR166+T ,3-Pin Silicon OscillatorApplicationsPART TEMP RANGE PIN-PACKAGEWhite GoodsMAX7381AXR106-T -40°C to +125°C 3 SC70-3Automotiv ..
MAX7384CRUK ,10 MHz, 2.7 V to 5.5 V, silicon oscillator with low-power frequency switching and reset outputfeatures a factory-programmed high-speed♦ Integrated PORoscillator, a 32.768kHz oscillator, a clock ..
MAX738A ,5V, Step-Down, Current-Mode PWM DC-DC ConvertersApplicationsMAX730AC/D 0°C to +70°C Dice*Portable InstrumentsMAX730AEPA -40°C to +85°C 8 Plastic DI ..
MAX738ACPA ,5V, Step-Down, Current-Mode PWM DC-DC Converters
MAX738ACPA ,5V, Step-Down, Current-Mode PWM DC-DC Converters
MAX738ACPA+ ,5V, Step-Down, Current-Mode PWM DC-DC ConvertersMAX730A/MAX738A/MAX744A19-0165; Rev 2; 1/965V, Step-Dow n,Current-Mode PWM DC-DC Converters________ ..
MAX379CPE+-MAX379CWG+-MAX379EWG+
8-Channel, High-Voltage, Fault-Protected Multiplexers
_______________General DescriptionThe 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, allchannels in the muxes
are turned off, and only a few nanoamperes of leakage cur-
rent 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 first-
generation fault-protected muxes. First, the Maxim protec-
tion scheme limits fault currents to nanoamp leakage
values rather than many milliamperes. This prevents dam-
age 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 requir-
ing pull-up resistors. Break-before-make operation is
guaranteed. Power dissipation is less than 2mW.
________________________ApplicationsData Acquisition Systems
Industrial and Process Control Systems
Avionics Test Equipment
Signal Routing Between Systems
____________________________FeaturesFault Input Voltage ±75V with Power Supplies OffFault Input Voltage ±60V with ±15V Power SuppliesAll Switches Off with Power Supplies OffOn Channel Turns OFF if Overvoltage Occurs on
Input or OutputOnly Nanoamperes of Input Current Under All
Fault ConditionsNo Increase in Supply Currents Due to Fault
ConditionsLatchup-Proof ConstructionOperates from ±4.5V to ±18V SuppliesAll Digital Inputs are TTL and CMOS CompatibleLow-Power Monolithic CMOSDesign
______________Ordering Information
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).
MAX378/MAX379
High-Voltage, Fault-Protected
Analog Multiplexers
________________________________________________________________Maxim Integrated Products1
__________________________________________________________Pin Configurations
Call toll free 1-800-998-8800 for free samples or literature.19-1902; Rev 1; 8/94
MAX378/MAX379
High-Voltage, Fault-Protected
Analog Multiplexers_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(V+ = +15V, V- = -15V; VAH(Logic Level High) = +2.4V, VAL(Logic Level Low) = +0.8V, unless otherwise noted.)
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.
Voltage between Supply Pins..............................................+44V
V+ to Ground...................................................................+22V
V- to Ground......................................................................-22V
DigitalInput Overvoltage:
V+......................................................................+4V........................................................................-4V
Analog Input with Multiplexer Power On..............................±65V
RecommendedV+.....................................+15V
Power SuppliesV-.......................................-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.....................................................0°C to +70°C
MAX378/379E..................................................-40°C to +85°C
MAX378/379M...............................................-55°C to +125°C
Storage Temperature Range.............................-65°C to +150°C
VEN, VA{
Note 1:Derate 12.8mW/°C above TA= +75°C
MAX378/MAX379
High-Voltage, Fault-Protected
Analog Multiplexers
_______________________________________________________________________________________3
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 50µA. 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 +25°C.
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.
ELECTRICAL CHARACTERISTICS (continued)(V+ = +15V, V- = -15V; VAH(Logic Level High) = +2.4V, VAL(Logic Level Low) = +0.8V, unless otherwise noted.)
MAX378/MAX379
High-Voltage, Fault-Protected
Analog Multiplexers_______________________________________________________________________________________10p
INPUT LEAKAGE vs.
INPUT VOLTAGE WITH V+ = V- = 0V
10μ
MAX378-1
VIN (V)
INPUT CURRENT (A)
100n
100p
10n
100μ
100μ
OFF CHANNEL LEAKAGE CURRENT vs.
INPUT VOLTAGE WITH ±15V SUPPLIES
100p
MAX378-2
VIN (V)
IIN(OFF)
(A)
10n
10p
10μ
100n
10n
OUTPUT LEAKAGE CURRENT vs. OFF CHANNEL
OVERVOLTAGE WITH ±15V SUPPLIES
100p
MAX378-3
VIN(OFF) (V)
IOUT(OFF)
(A)
10p
DRAIN-SOURCE ON-RESISTANCE vs.
ANALOG INPUT VOLTAGE
MAX3784
ANALOG INPUT (V)
DS(ON)
__________________________________________Typical Operating Characteristics
NOTE:Typical RDS(ON)match @ +10V
Analog in (±15V supplies) = 2%
for lowest to highest RDS(ON)
channel; @ -10V Analog in,
match = 3%.
Figure 1. Access Time vs. Logic Level (High)
MAX378/MAX379
High-Voltage, Fault-Protected
Analog Multiplexers
_______________________________________________________________________________________5Figure 2. Break-Before-Make Delay (tOPEN)
Figure 3. Enable Delay (tON(EN), tOFF(EN))
Figure 4. Input Leakage Current (Overvoltage)
Figure 5. Input Leakage Current (with Power Supplies OFF)
MAX378/MAX379
High-Voltage, Fault-Protected
Analog Multiplexers_______________________________________________________________________________________
_______________Typical ApplicationsFigure 6 shows a typical data acquisition system
using the MAX378 multiplexer. Since the multiplexer
is driving a high-impedance input, its error is a func-
tion of its own resistance (RDS(ON)) times the multi-
plexer leakage current (IOUT(ON)) and the amplifier
bias current (IBIAS):
VERR= RDS(ON)x (IOUT(ON)+ IBIAS(MAX420))
= 2.0kΩx (2nA + 30pA)
= 18.0µV maximum error
In most cases, this error is low enough that preamplifi-
cation of input signals is not needed, even with very
low-level signals such as 40µV/°C from type J thermo-
couples.
In systems with fewer than eight inputs, an unused chan-
nel 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 pro-
grammable-gain amplifier, with gains ranging from 1 to
10,000. The guaranteed 5µV unadjusted offset of the
MAX420 maintains high signal accuracy, while program-
mable gain allows the output signal level to be scaled to
the optimum range for the remainder of the data acqui-
sition 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.
Truth Table—MAX378
Truth Table—MAX379
Note:Logic “0” = VAL≤0.8V, Logic “1” = VAH‡2.4V
Figure 6. Typical Data Acquisition Front End
