MAX378-MAX379 Maxim, MAX378-MAX379 Datasheet

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MAX378-MAX379

Manufacturer Part Number
MAX378-MAX379
Description
High-Voltage / Fault-Protected Analog Multiplexers
Manufacturer
Maxim
Datasheet
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 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.
________________________Applications
19-1902; Rev 1; 8/94
Call toll free 1-800-998-8800 for free samples or literature.
_______________General Description
__________________________________________________________Pin Configurations
Pin Configurations continued at end of data sheet.
Data Acquisition Systems
Industrial and Process Control Systems
Avionics Test Equipment
Signal Routing Between Systems
OUT
IN1
IN2
IN3
IN4
EN
A0
V-
________________________________________________________________ Maxim Integrated Products
1
2
3
4
5
6
7
8
MAX378
DIP
16
15
14
13
12
11
10
9
A1
A2
GND
V+
IN5
IN6
IN7
IN8
High-Voltage, Fault-Protected
TOP VIEW
____________________________Features
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).
______________Ordering Information
MAX378CPE
MAX378CWG
MAX378CJE
MAX378C/D
MAX378EPE
MAX378EWG
MAX378EJE
MAX378MJE
MAX378MLP
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
PART
Analog Multiplexers
OUTA
IN1A
IN2A
IN3A
IN4A
EN
A0
V-
1
2
3
4
5
6
7
8
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
-55°C to +125°C
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
0°C to +70°C
MAX379
DIP
16
15
14
13
12
11
10
9
A1
GND
V+
IN1B
IN2B
IN3B
IN4B
OUTB
16 Plastic DIP
24 Wide SO
16 CERDIP
Dice**
16 Plastic DIP
24 Wide SO
16 CERDIP
16 CERDIP
20 LCC*
PIN-PACKAGE
1

Related parts for MAX378-MAX379

MAX378-MAX379 Summary of contents

Page 1

... 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’ ...

Page 2

... Peak Current 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 Note 1: Derate 12.8mW/°C above T (Logic Level Low ...

Page 3

... Figure 3 Full +25°C Figure 3 Full +25° 0.8V 1kΩ 15pF +25° 100kHz RMS +25°C MAX378 +25°C MAX379 +25°C +25°C +25° 0.8V or 2.4V EN All Full A +25° 0.8V or 2.4V EN All Full (Note 7) +25°C = cold temp. 0° ...

Page 4

... V (V) IN NOTE: Typical R match @ +10V DS(ON) Analog in (±15V supplies for lowest to highest R DS(ON) channel; @ -10V Analog in, match = 3%. MAX378 3.0V ADDRESS AH DRIVE (V 50% 0V +10V OUTPUT A 90% -10V t A Figure 1. Access Time vs. Logic Level (High) 4 _______________________________________________________________________________________ OFF CHANNEL LEAKAGE CURRENT vs. INPUT VOLTAGE WITH ±15V SUPPLIES ...

Page 5

... MAX358 3.0V AH ADDRESS DRIVE ( OUTPUT 50% 50% t OPEN Figure 2. Break-Before-Make Delay (t ) OPEN MAX378 3.0V AH ENABLE DRIVE 50% 0V 90% OUTPUT 90% t ON(EN) t OFF(EN) Figure 3. Enable Delay ( ON(EN) OFF(EN) +5V +15V MAX378 EN I OUT IN1 IN8 ±60V V- GND V ±10V -15V ANALOG SIGNAL Figure 4. Input Leakage Current (Overvoltage) ...

Page 6

... ZERO REFERENCE V- -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 func- tion of its own resistance (R ) times the multi- DS(ON) plexer leakage current (I ...

Page 7

... 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 ...

Page 8

... 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 set- , which turns it tling time of the following amplifiers and S/H. Another limit- GS ing factor is the RC time constant of the multiplexer ...

Page 9

... Differential at the MAX378 output, which is R A-B signal source resistance in most cases, since the load -2pC driven by the MAX378 is usually a high impedance. For -1pC a signal source impedance of 10kΩ or lower, the DC -2pC crosstalk exceeds 120dB. -5pC ...

Page 10

... N. MAX378 IN1 6 19 IN2 7 18 IN3 8 17 IN4 OUT IN1 N.C. 6 MAX378 IN2 7 IN3 8 LCC 10 ______________________________________________________________________________________ TOP VIEW N.C. GND N.C. N. IN1A IN5 IN2A IN6 IN3A N.C. IN7 IN4A N.C. N.C. N.C. N.C. OUTA IN8 18 GND ...

Page 11

... IN7 IN6 IN5 V+ GND A2 (3.835mm) NOTE: Connect substrate leave it floating. OUTB OUTA IN4B IN3B IN2B IN1B V+ GND (3.835mm) NOTE: Connect substrate leave it floating. MAX378 IN8 OUT IN4 IN3 0.229" (5.816mm) IN2 IN1 0.151" MAX379 IN4A IN3A 0.229" ...

Page 12

... A1 e Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied ...

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