MAXIM MAX378, MAX379 User Manual

19-1902; Rev 1; 8/94
High-Voltage, Fault-Protected
Analog Multiplexers
_______________General Description
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
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
____________________________Features
Fault 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 Output
Only Nanoamperes of Input Current Under All
Fault Conditions
No Increase in Supply Currents Due to Fault
Conditions
Latchup-Proof ConstructionOperates from ±4.5V to ±18V SuppliesAll Digital Inputs are TTL and CMOS CompatibleLow-Power Monolithic CMOS Design
______________Ordering Information
PART
MAX378CPE
MAX378CWG MAX378CJE 0°C to +70°C MAX378C/D 0°C to +70°C Dice** MAX378EPE MAX378EWG -40°C to +85°C MAX378EJE MAX378MJE -55°C to +125°C MAX378MLP -55°C to +125°C 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).
TEMP. RANGE PIN-PACKAGE
0°C to +70°C 0°C to +70°C
-40°C to +85°C 16 Plastic DIP
-40°C to +85°C 16 CERDIP
16 Plastic DIP 24 Wide SO 16 CERDIP
24 Wide SO
16 CERDIP
MAX378/MAX379
__________________________________________________________Pin Configurations
A0
1 2
EN
V-
3
IN1 IN2 IN3
IN4
OUT
Pin Configurations continued at end of data sheet.
MAX378
4 5 6 7 8
DIP
________________________________________________________________
A1
16
A2
15
GND
14 13
V+
12
IN5
11
IN6
10
IN7
9
IN8
TOP VIEW
IN1A IN2A IN3A
IN4A
OUTA
A0
1 2
EN
V-
3
MAX379
4 5 6 7 8
DIP
A1
16
GND
15
V+
14 13
IN1B
12
IN2B
11
IN3B
10
IN4B
9
OUTB
Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
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:
VEN, V
Analog Input with Multiplexer Power On..............................±65V
Analog Input with Multiplexer Power Off..............................±80V
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.
V+......................................................................+4V
A
{
V-........................................................................-4V
Recommended V+.....................................+15V
{}
Power Supplies V-.......................................-15V
ELECTRICAL CHARACTERISTICS
(V+ = +15V, V- = -15V; VAH(Logic Level High) = +2.4V, VAL(Logic Level Low) = +0.8V, unless otherwise noted.)
MAX378/MAX379
CONDITIONS UNITS
V
= ±10V, IIN= 100µA
OUT
VAL= 0.8V, VAH= 2.4V VIN= ±10V, V
= 0.8V (Note 6)
V
EN
V
OUT
VEN= 0.8V MAX378 (Note 6) MAX379
V
IN(ALL)
VAH= VEN= 2.4V MAX378 VAL= 0.8V (Note 5) MAX379
(Note 2) MAX379 only
(Note 6)
V
OUT
(Notes 3, 4) VIN= ±60V, V
(Notes 3, 4) VIN= ±75V, VEN= V
A0= A1= A2= 0V or 5V
(Note 4) (Note 4)
VA= 5V or 0V (Note 5)
OUT
= ±10V, VIN= 10V
= V
OUT
= 0V, VIN= ±60V
OUT
STATIC
ON Resistance
OFF Input Leakage Current
OFF Output Leakage Current
ON Channel Leakage Current
Analog Signal Range Differential OFF Output
Leakage Current
FAULT
Output Leakage Current (with Input Overvoltage)
Input Leakage Current (with Overvoltage)
Input Leakage Current (with Power Supplies Off)
CONTROL
Input Low Threshold Input High Threshold Input Leakage Current
(High or Low)
SYMBOLPARAMETER TEMP
r
DS(ON)
I
IN(OFF)
I
OUT(OFF)
I
OUT(ON)
AN
DIFF
I
OUT(OFF)
IN(OFF)
IN(OFF)
AL AH
A
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
Note 1: Derate 12.8mW/°C above TA= +75°C
0°C to +70°C
and
-40°C to +85°C
2.0 3.5
3.0 4.0
-1.0 0.03 1.0
-50 50
-2.0 0.1 2.0
-200 200
-100 100
-20 0.1 20
-600 600
-15 +15
-50 50
20
2.4
-1.0 1.0
±
= 10V
±
= ±10V
= ±10V
OUT
-55°C to +125°C
MIN TYP MAX MIN TYP MAX
+25°C
Full
+25°C
Full
+25°C
Full Full
+25°C
Full Full Full
Full
+25°C
Full
+25°C
= 0V
+25°C 20
Full Full
Full
2.0 3.0
3.0 4.0
-0.5 0.03 0.5
-50 50
-1.0 0.1 1.0
-100 100
-10 0.1 10
-300 300 -300 300
20 40
0.8
k
nA
nA-200 200
nA-600 600
V-15 +15V
nA-50 50I
nA20 µA10
µA25I
µA10I
V0.8V V2.4V
µA-1.0 1.0I
2 _______________________________________________________________________________________
High-Voltage, Fault-Protected
Analog Multiplexers
ELECTRICAL CHARACTERISTICS (continued)
(V+ = +15V, V- = -15V; VAH(Logic Level High) = +2.4V, VAL(Logic Level Low) = +0.8V, unless otherwise noted.)
1000
1000
0°C to +70°C
and
-40°C to +85°C
400 1000
1500
300
1000
1.2
3.5
50 68
5 25 12
5
0.1
0.2 1.0
0.5 1.0
0.01 0.1
0.02 0.1
±4.5 ±18
.
SYMBOLPARAMETER
DYNAMIC
Access Time +25°C 0.5 1.0 Break-Before-Make Delay
(Figure 2)
Enable Delay (ON)
Enable Delay (OFF)
Settling Time (0.1%)
(0.01%)
“OFF Isolation”
Channel Input Capacitance Channel Output Capacitance
Digital Input Capacitance
Input to Output Capacitance
SUPPLY
Power-Supply Range for Continuous Operation
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 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 T Note 7: Electrical characteristics, such as ON Resistance, will change when power supplies other than ±15V are used.
t
ON(EN)
t
OFF(EN)
t
SETT
IN(OFF)
C
OUT(OFF)
DS(OFF)
I+Positive Supply Current
I-Negative Supply Current
OP
A
OFF
(ISO)
A
A
= cold temp.
CONDITIONS
Figure 1 µs0.5 1.0t VEN= +5V, VIN= ±10V
A0, A1, A2strobed
Figure 3
Figure 3
VEN= 0.8V, RL= 1k, CL= 15pF V = 7V
VEN= 0.8V or 2.4V All VA= 0V or 5V
VEN= 0.8V or 2.4V All VA= 0V or 5V
(Note 7)
, f = 100kHz
RMS
MAX378 MAX379
-55°C to +125°C
TEMP
MIN TYP MAX MIN TYP MAX
+25°C 25 200 +25°C
Full
+25°C
Full
+25°C
+25°C +25°C +25°C
+25°C
+25°C
+25°C
Full
+25°C
Full
+25°C
400 750
300 500
1.2
3.5
25 12
0.1 0.6
0.3 0.7
0.01 0.1
0.02 0.2
Detailed Description
MAX378/MAX379
UNITS
ns25 200tON-t
ns
ns
µs
dB50 68OFF pF5C pF
pF5C
pF0.1C
mA
mA
V±4.5 ±18V
_______________________________________________________________________________________ 3
High-Voltage, Fault-Protected Analog Multiplexers
__________________________________________Typical Operating Characteristics
INPUT LEAKAGE vs.
INPUT VOLTAGE WITH V+ = V- = 0V
1m
100µ
10µ
1µ
100n
10n
INPUT CURRENT (A)
1n
100p
10p
MAX378/MAX379
-100 -50 50 100
NOTE: Typical R
Analog in (±15V supplies) = 2% for lowest to highest R channel; @ -10V Analog in,
-80V
OPERATING
RANGE
V
DS(ON)
IN
+80V
0
(V)
match @ +10V
DS(ON)
match = 3%.
MAX378-1
OFF CHANNEL LEAKAGE CURRENT vs. INPUT VOLTAGE WITH ±15V SUPPLIES
100µ
10µ
1µ
100n
(A)
10n
IN(OFF)
I
1n
100p
10p
1p
-120 -60 60 120
OPERATING
RANGE
-60V
V
IN
0
(V)
DRAIN-SOURCE ON-RESISTANCE vs.
ANALOG INPUT VOLTAGE
(k)
DS(ON)
R
7
6
5
4
3
2
1 0
+3.5V +4V
+13V
-10 -5 5 15-15 0 20
±5V
SUPPLIES
SUPPLIES
ANALOG INPUT (V)
±15V
OUTPUT LEAKAGE CURRENT vs. OFF CHANNEL
OVERVOLTAGE WITH ±15V SUPPLIES
10n
MAX378-2
1n
(A)
100p
OUT(OFF)
+60V
+13V
10
I
10p
1p
-120 -60 60 120
MAX3784
-60V
OPERATING
RANGE
0
V
IN(OFF)
(V)
MAX378-3
+60V
A2
MAX378
A1 A0
+V
AH
EN
GND
IN2-IN7
OUT
IN1
±10V
IN2
±
IN8
10V
+10V
50%
MAX378: VAH = 3.0V
90%
t
A
ADDRESS
DRIVE (V
OUTPUT A
-10V
)
A
0V
V
A
50
Figure 1. Access Time vs. Logic Level (High)
4 _______________________________________________________________________________________
PROBE
10M
14pF
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