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MAX4709
User Manual
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MAXIM MAX4708, MAX4709 User Manual

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General Description
The MAX4708/MAX4709 8-to-1 and dual 4-to-1 fault-pro­tected multiplexers are pin compatible with the industry­standard DG508/DG509. The MAX4708/MAX4709 are similar to the MAX4508/MAX4509, but these devices do not have clamp diodes to the supply rails on the switch outputs. These multiplexers feature fault-protected inputs, rail-to-rail signal-handling capability, and do not require power-supply sequencing.
Both devices offer ±40V overvoltage protection with the supplies off, ±36V protection with the supplies on, and feature 400Ω (max) on-resistance with 15Ω (max) matching between channels. The MAX4708/MAX4709 operate with dual supplies of ±4.5V to ±20V or a single supply of +9V to +36V. All digital inputs have TTL logic­compatible thresholds, ensuring both TTL and CMOS logic compatibility when using a single +12V supply or dual ±15V supplies.
For low-voltage applications requiring fault protection, refer to the MAX4711/MAX4712/MAX4713 data sheet.
Applications
Data-Acquisition Systems
Industrial and Process Control
Avionics
Signal Routing
Redundancy/Backup Systems
ATE Systems
Hot Swap
Features
♦ No Power-Supply Sequencing Required
♦ All Channels Off with Power Off
♦ Rail-to-Rail Signal Handling
♦ 400Ω (max) On-Resistance
♦ ±40V Fault Protection with Power Off
♦ ±25V Fault Protection with ±15V Supplies
♦ 100ns Fault-Response Time
♦ ±4.5V to ±20V Dual Supplies
♦ +9V to +36V Single Supply
♦ TTL/CMOS-Compatible Logic Inputs
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
A1
A2
GND
V+
NO1
V-
EN
A0
TOP VIEW
MAX4708
NO5
NO6
NO7
NO8
COM
NO4
NO3
NO2
SO/DIP
LOGIC
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
A1
GND
V+
NO1B
NO1A
V-
EN
A0
MAX4709
NO2B
NO3B
NO4B
COMB
COMA
NO4A
NO3A
NO2A
SO/DIP
LOGIC
Pin Configurations/Functional Diagrams
19-4804; Rev 1; 12/08
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
PART TEMP RANGE PIN-PACKAGE
MAX4708ESE -40°C to +85°C 16 Narrow SO
MAX4708EWE -40°C to +85°C 16 Wide SO
MAX4708EPE -40°C to +85°C 16 Plastic DIP
MAX4709ESE -40°C to +85°C 16 Narrow SO
MAX4709EWE -40°C to +85°C 16 Wide SO
MAX4709EPE -40°C to +85°C 16 Plastic DIP
Pin Configurations/Functional Diagrams continued at end of data sheet.
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/ Dual 4-to-1 Multiplexers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS—Dual Supplies
(V+ = +15V, V- = -15V, V
A_H
= +2.4V, V
A_L
= +0.8V, VEN= +2.4V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 2)
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.
(All Voltages Referenced to GND)
V+ ........................................................................-0.3V to +44.0V
V- .........................................................................-44.0V to +0.3V
V+ to V-................................................................-0.3V to +44.0V
COM_, A_, EN (Note 1)........................ (V+ + 0.3V) to (V- - 0.3V)
NO_.........................................................(V+ - 40V) to (V- + 40V)
NO_ to COM_ ..........................................................-36V to +36V
NO_ Voltage with Switch Power On ........................-30V to +30V
NO_ Voltage with Switch Power Off ........................-40V to +40V
Continuous Current into any Terminal. .............................±30mA
Peak Current into any Terminal
(pulsed at 1ms, 10% duty cycle)................................±100mA
Continuous Power Dissipation (TA= +70°C)
16 Narrow SO (derate 8.70mW/°C above +70°C) .......696mW
16 Plastic DIP (derate 10.53mW/°C above +70°C) .....842mW
16 Wide SO (derate 9.52mW/°C above +70°C)...........762mW
Operating Temperature Range
MAX4708E_ E/MAX4709E_E ...........................-40°C to +85°C
Junction Temperature..................................................... +150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: COM_, EN, and A_ pins are not fault protected. Signals on COM_, EN, or A_ exceeding V+ or V- are clamped by internal
diodes. Limit forward-diode current to maximum current rating.
PARAMETER
CONDITIONS T
A
UNITS
ANALOG SWITCH
V
NO_
(Notes 3, 4) E V- V+ V
400
On-Resistance R
ON
V
COM_
= ±10V, I
NO_
= 0.2mA
E 500
Ω
15
On-Resistance Match Between Channels
ΔR
ON
V
COM_
= ±10V, I
NO_
= 0.2mA
(Note 5)
E20
Ω
NO_ Off-Leakage Current
)
V
COM_
= ±10V, V
NO_
= ±10V
(Note 6)
E-5 +5
nA
-2 +2
E-20
-1 +1
COM_ Off-Leakage Current
)
V
COM_
= ±10V,
V
NO_
= ±10V
(Note 6)
E-10
nA
-2 +2
E-25
-1 +1
COM_ On-Leakage Current
)
V
COM_
= ±10V,
V
NO_
= ±10V, or
floating (Note 6)
E-15
nA
SYMBOL
MIN TYP MAX
Fault-Free Analog Signal Range
+25°C 300
+25°C
I
NO_(OFF
MAX4708
I
COM_(OFF
I
COM_(ON
MAX4709
MAX4708
MAX4709
+25°C -0.5 +0.5
+25°C
+25°C
+25°C
+25°C
+20
+10
+25
+15
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)
(V+ = +15V, V- = -15V, V
A_H
= +2.4V, V
A_L
= +0.8V, VEN= +2.4V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS T
A
MIN
TYP
MAX
UNITS
FAULT PROTECTION
Power on -25
Fault-Protected Analog Signal Range (Notes 3, 4)
V
NO_
Power off
-40
V
-1 +1
COM_ Output Leakage Current, Supplies On
I
COM_
V
NO_
= ±25, VEN = 0
E-10
µA
-1 +1
NO_ Input Leakage Current, Supplies On
I
NO_
V
NO_
= ±25V, V
COM_
= ±10V,
V
EN
= 0
E-10
µA
-1 +1
NO_ Input Leakage Current, Supplies Off
I
NO_
V
NO_
= ±40V, V
COM
= 0,
V+ = 0, V- = 0
E-10
µA
Fault-Trip Threshold E
V-
V+
V
±Fault Output Turn-Off Delay RL = 10kΩ, V
NO_
= ±25V
ns
±Fault Recovery Time RL = 10kΩ, V
NO_
= ±25V
µs
LOGIC INPUT (VEN, VA_)
Logic Threshold High V
IH
E2.4 V
Logic Threshold Low V
IL
E0.8V
Input Leakage Current I
IN
V
A_
= 0.8V or 2.4V E -1 +1 µA
SWITCH DYNAMIC CHARACTERISTICS
275
Enable Turn-On Time t
ON
V
NO_
= ±10V, RL = 1kΩ,
C
L
= 35pF, Figure 3 (Note 7)
E 400
ns
200
Enable Turn-Off Time t
OFF
V
NO_
= ±10V, RL = 1kΩ,
C
L
= 35pF, Figure 3 (Note 7)
E 250
ns
350
Transition Time t
TRANS
RL = 1kΩ, CL = 35pF, Figure 2 (Note 7)
E 500
ns
1
Settling Time t
SETT
V
NO_
= 5V, RL = 1kΩ,
C
L
= 35pF
E
2.5
µs
Break-Before-Make Time Delay t
BBM
V
NO_
= ±10V, RL = 1kΩ, Figure 4
(Note 4)
E1080 ns
Charge Injection Q
V
NO
_
= 0, RS = 0, CL = 1.0nF,
Figure 5
0pC
Off-Isolation V
ISO
C L = 15p F, Fi g ur e 6 ( N ote 8)
-70 dB
+25°C
+25°C
+25°C
+25°C
+25°C 100
+25°C 1.5
+25°C 160
- 0.4
+25
+40
+10
+10
+10
+ 0.4
f = 1M H z, V
N O_
= 1V
+25°C 120
+25°C 170
0.1%
0.01%
+25°C
, RL = 75Ω ,
RM S
+25°C
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/ Dual 4-to-1 Multiplexers
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)
(V+ = +15V, V- = -15V, V
A_H
= +2.4V, V
A_L
= +0.8V, VEN= +2.4V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 2)
PARAMETER
CONDITIONS T
A
UNITS
Channel-to-Channel Crosstalk V
CT
C L = 15p F, Fi g ur e 7 ( N ote 9)
-62 dB
NO_ Off-Capacitance
)
f = 1MHz, Figure 8
10 pF
MAX4708 19
COM_ Off-Capacitance
f = 1MHz, Figure 8
MAX4709
14
pF
MAX4708 28
COM_ On-Capacitance
f = 1MHz, Figure 8
MAX4709
22
pF
POWER SUPPLY
Power-Supply Range V+, V- E
V
525
V+ Supply Current I+
All V
A_
= 0 or 5V, V
NO_
= 0,
V
EN
= 5V
E 750
µA
300
V- Supply Current I-
All V
A_
= 0 or 5V, V
NO_
= 0,
V
EN
= 5V
E 400
µA
300
GND Supply Current I
GND
All V
A_
= 0 or 5V, V
NO_
= 0,
V
EN
= 5V
E 500
µA
ELECTRICAL CHARACTERISTICS—Single +12V Supply
(V+ = +12V, V- = 0, V
A_H
= +2.4V, V
A_L
= +0.8V, VEN= +2.4V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 2)
PARAMETER
CONDITIONS T
A
ANALOG SWITCH
V
NO_
Power on or off (Note 3) E
V+ V
950
On-Resistance R
ON
V
COM_
= 10V, I
NO_
= 0.2mA
E
Ω
10 35
On-Resistance Match Between Channels
ΔR
ON
V
COM_
= 10V, I
NO_
= 0.2mA
(Note 5)
50
Ω
NO_ Off-Leakage Current
)
(Notes 6, 10)
E-10
nA
-2 +2
E-20
-1 +1
COM_ Off-Leakage Current
)
V
COM_
= 10V, 1V,
V
NO_
= 1V, 10V
(Notes 6, 10)
E-10
nA
SYMBOL
f = 1M H z, V
N O_
= 1V
, RL = 75Ω ,
RM S
+25°C
MIN TYP MAX
C
N_(OFF
C
C OM _( OF F )
C
C OM _( ON )
Fault-Free Analog Signal Range
SYMBOL
V
= 10V, 1V, V
I
NO_(OFF
I
COM_(OFF
COM_
= 1V, 10V
NO_
+25°C
+25°C
+25°C
±4.5 ±20.0
+25°C 370
+25°C 200
+25°C 200
MIN TYP MAX UNITS
-0.3
+25°C 630
+25°C
C, E
+25°C -0.5 0.01 +0.5
+25°C
MAX4708
MAX4709
+25°C
1100
+10
+20
+10
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS—Single +12V Supply (continued)
(V+ = +12V, V- = 0, V
A_H
= +2.4V, V
A_L
= +0.8V, VEN= +2.4V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 2)
PARAMETER
CONDITIONS T
A
-2 +2
E-25
-1 +1
COM_ On-Leakage Current
)
V
COM_
= 10V, 1V;
V
NO_
= 10V, 1V, or
E-15
nA
FAULT PROTECTION
Power on -36
Fault-Protected Analog Signal Range (Notes 3, 10)
V
NO
_
Power off
E
-40
V
-1 +1
COM_ Output Leakage Current, Supplies On
I
COM
_
V
NO_
= ±36V, V+ = 12V
(Notes 3, 10)
E-10
µA
-1 +1
NO_ Input Leakage Current, Supplies On
I
NO
_
V
NO_
= ±36V, V
COM_
= 0,
V+ = 12V (Notes 3, 10)
E-10
µA
-1 +1
NO_ Input Leakage Current, Supply Off
I
NO
_
V
NO_
= ±40V, V+ = 0, V- = 0
(Notes 3, 10)
E-10
µA
LOGIC INPUT (VEN, VA_)
Logic Threshold High V
IH
E2.4 V
Logic Threshold Low V
IL
E0.8V
Input Leakage Current I
IN
VA_ = 0.8V or 2.4V E -1
+1 µA
SWITCH-DYNAMIC CHARACTERISTICS
500
Enable Turn-On Time t
ON
V
COM_
= 10V, RL = 2kΩ,
C
L
= 35pF, Figure 3 (Note 7)
E 700
ns
250
Enable Turn-Off Time t
OFF
V
COM_
= 10V, RL = 2kΩ,
C
L
= 35pF, Figure 3 (Note 7)
E 350
ns
400
Transition Time t
TRANS
RL = 2kΩ, CL = 35pF, Figure 2 (Note 7)
E 600
ns
0.1% 1
Settling Time t
SETT
CL = 35pF
0.01%
E
2.5
µs
Break-Before-Make Time Delay t
BBM
V
COM_
= 10V, RL = 2kΩ, Figure 4
(Note 4)
50
ns
Charge Injection Q
V
NO_
= 0, RS = 0, CL = 1.0 nF,
Figure 5
2pC
NO_ Off-Capacitance
)
f = 1MHz, V
NO_ =
0, Figure 8
5pF
COM_ Off-Capacitance
)
f = 1MHz, V
NO_ =
0, Figure 8
5pF
COM_ On-Capacitance
)
f = 1MHz, V
COM_
= V
NO_ =
0,
Figure 8
28 pF
SYMBOL
MAX4708
I
COM_(ON
floating (Notes 6, 10)
MAX4709
V
= 5V, RL = 1kΩ,
NO_
C
NO_(OFF
C
COM_(OFF
C
COM_(ON
MIN TYP MAX UNITS
+25°C
+25
+25°C
+15
+36
+40
+25°C
+10
+25°C
+10
+25°C
+10
0.03
+25°C 240
+25°C 100
+25°C 180
+25°C
+25°C
+25°C
+25°C
+25°C
100
Note 2: The algebraic convention is used in this data sheet; the most negative value is shown in the minimum column. Note 3: NO_ pins are fault protected and COM_ pins are not fault protected. The max input voltage on NO_ pins depends on the
COM_ load configuration. Generally, the max input voltage is ±36V with ±15V supplies and a load referred to ground. For more detailed information, see the
NO_ Input Voltage
section.
Note 4: Guaranteed by design and not production tested. Note 5: ΔR
ON
= R
ON(MAX)
- R
ON(MIN)
.
Note 6: Leakage parameters are 100% tested at the maximum rated hot temperature and guaranteed by correlation at T
A
=
+25°C.
Note 7: Dynamic testing is 100% functionally tested on the ATE system and correlated with the initial design characterization per
Figures 2 and 3.
Note 8: Off-Isolation = 20
✕ log
10(VCOM_
/ V
NO_
), where V
COM_
= output and V
NO_
= input to open switch.
Note 9: Between any two analog inputs. Note 10: Guaranteed by testing with dual supplies.
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/ Dual 4-to-1 Multiplexers
6 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS—Single +12V Supply (continued)
(V+ = +12V, V- = 0, V
A_H
= +2.4V, V
A_L
= +0.8V, VEN= +2.4V, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at
T
A
= +25°C.) (Note 2)
PARAMETER
CONDITIONS T
A
Off-Isolation V
ISO
f = 1MHz, V
NO_
= 1V
RMS
, RL =
-70 dB
Channel-to-Channel Crosstalk V
CT
f = 1MHz, V
NO_
= 1V
RMS
, RL =
-62 dB
POWER SUPPLY
Power-Supply Range V+ E 9 36 V
300
All V
A_
= V
EN
= 5V, V
NO_
= 0
E 450
250
V+ Supply Current I+
All V
A_
= 0 or V+, V
NO_
= 0, VEN =
0 or V+
E 375
µA
Typical Operating Characteristics
(V+ = +15V, V- = -15V, VEN= +2.4V, TA= +25°C, unless otherwise noted.)
SYMBOL
MIN TYP MAX UNITS
75Ω, CL = 15pF, Figure 6 (Note 8)
75Ω, CL = 15pF, Figure 7 (Note 9)
+25°C
+25°C
+25°C 180
+25°C 112
ON-RESISTANCE vs. V
COM
(DUAL SUPPLIES)
1000
V+ = +15V V- = -15V
V+ = +4.5V V- = -4.5V
V+ = +20V V- = -20V
V+ = +10V V- = -10V
V
(V)
COM
151050-5-10-15
800
600
(Ω)
ON
R
400
200
0
-20 20
1000
800
MAX4708/09 toc01
600
(Ω)
ON
R
400
200
ON-RESISTANCE vs. V
COM
(SINGLE SUPPLY)
V+ = +9V V- = 0V
V+ = +12V V- = 0V
V+ = +15V V- = 0V
V+ = +36V V- = 0V
0
036
V
COM
V+ = +20V V- = 0V
V+ = +30V V- = 0V
302418126
(V)
ON-RESISTANCE vs. V
600
V+ = +15V V- = -15V
500
MAX4708/09 toc02
400
(Ω)
300
ON
R
200
100
TA = +25°C
0
-15 15
(DUAL SUPPLIES)
TA = +70°C
TA = -40°C
V
AND TEMPERATURE
COM
TA = +125°C
TA = +85°C
TA = -55°C
(V)
COM
MAX4708/09 toc03
1050-5-10
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
_______________________________________________________________________________________ 7
ENABLE TURN-ON/OFF TIMES
vs. SUPPLY VOLTAGE (DUAL SUPPLIES)
MAX4708/09 toc07
SUPPLY VOLTAGE (V+, V-)
t
ON
/t
OFF
(ns)
15105
100
200
300
400
500
0
020
V
NO_
= ±10V
t
ON
t
OFF
ENABLE TURN-ON/OFF TIMES
vs. SUPPLY VOLTAGE (SINGLE SUPPLY)
MAX4708/09 toc08
SUPPLY VOLTAGE (V+)
t
ON
/t
OFF
(ns)
2718
50
100
150
200
250
300
0
936
V- = GND, V
NO_
= +10V
t
ON
t
OFF
Typical Operating Characteristics (continued)
(V+ = +15V, V- = -15V, VEN= +2.4V, TA= +25°C, unless otherwise noted.)
ON-RESISTANCE vs. V
(SINGLE SUPPLY)
1000
V+ = +12V V- = 0V
800
600
(Ω)
ON
R
400
200
0
012
TA = +70°C
TA = +25°C
AND TEMPERATURE
COM
TA = +125°C
TA = +85°C
TA = -40°C
V
(V)
COM
TA = -55°C
108642
1000
MAX4708/09 toc04
100
LEAKAGE CURRENT (pA)
0.1
LEAKAGE CURRENT vs. TEMPERATURE
V+ = +15V, V- = -15V,
±
= 10V, VNO = ±10V
V
COM
I
COM_ON
10
I
1
-40 -15 10 60 85
COM_OFF
TEMPERATURE (°C)
35
I
NO_OFF
MAX4708/09 toc05
Q (pC)
(ns)
/t t
CHARGE INJECTION vs. V
10
5
DUAL SUPPLIES: ±15V
0
SINGLE SUPPLY: +12V
-5
-10
-15 15 V
(V)
COM
ENABLE ON/OFF TIMES
vs. TEMPERATURE
300
V+ = +15V V- = -15V
250
200
t
OFF
ON
150
100
ON
t
OFF
COM
MAX4708/09 toc06
1050-5-10
MAX4708/09 toc09
SUPPLY CURRENT vs. TEMPERATURE
= 0)
(V
500
400
300
200
100
0
-100
-200
SUPPLY CURRENT (μA)
-300
-400
-500
-40 85
A_
V+ = +15V, V- = -15V, VA_ = 0
I+
I
GND
I-
TEMPERATURE (°C)
603510-15
MAX4708/09 toc10
SUPPLY CURRENT vs. TEMPERATURE
= +5V)
(V
600
500
400
300
200
100
0
-100
SUPPLY CURRENT (μA)
-200
-300
-400
-40 85
A_
V+ = +15V, V- = -15V, VA_ = +5V
I+
I
GND
I-
TEMPERATURE (°C)
50
0
-40 85
TEMPERATURE (°C)
603510-15
LOGIC-LEVEL THRESHOLD VOLTAGE
vs. SUPPLY VOLTAGE
3.0
MAX4708/09 toc11
2.5
DUAL SUPPLIES
2.0
THRESHOLD VOLTAGE (V)
1.5
1.0
603510-15
040
SUPPLY VOLTAGE (V)
SINGLE SUPPLY
MAX4708/09 toc12
3530252015105
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/ Dual 4-to-1 Multiplexers
8 _______________________________________________________________________________________
FAULT CURRENT vs. FAULT VOLTAGE
(DUAL SUPPLIES)
MAX4708/09 toc14
V
COM
(V)
I
COM
(μA)
4020-60 -40 -20 0
-150
-100
-50
0
50
100
150
200
-200
-80 60
FOR |V
COM
| < V
SUPPLY
,
I
COM
= V
COM
/ R
L
V+ = +15V V- = -15V
FAULT CURRENT vs. FAULT VOLTAGE
(SINGLE SUPPLY)
MAX4708/09 toc15
V
COM
(V)
I
COM
(μA)
6040-60 -40 -20 0 20
-150
-100
-50
0
50
100
150
200
-200
-80 80
FOR 0V < V
COM
< V
SUPPLY
,
I
COM
= V
COM
/ R
L
V+ = +12V V- = GND
Typical Operating Characteristics (continued)
(V+ = +15V, V- = -15V, VEN= +2.4V, TA= +25°C, unless otherwise noted.)
20
FREQUENCY RESPONSE
V+ = +15V V- = -15V
0
-20
-40
LOSS (dB)
-60
-80
-100
0.001 1 10 1000.01 0.1 1000
INPUT OVERVOLTAGE vs. OUTPUT VOLTAGE
BANDWIDTH
CROSSTALK
OFF-ISOLATION
FREQUENCY (MHz)
4.00μs
MAX4708/09 toc16
MAX4708/09 toc13
GND
V
NO_
INPUT 10V/div
GND
V
COM_
OUTPUT 200mV/div
INPUT OVERVOLTAGE vs. OUTPUT VOLTAGE
200μs
MAX4708/09 toc17
V
NO_
INPUT 10V/div
GND
V
COM_
OUTPUT 10V/div
GND
FAULT RECOVERY TIME (POSITIVE INPUT)
V
NO_
INPUT
10V/div
GND
1.00μs
MAX4708/09 toc18
V
COM_
OUTPUT 5V/div
GND
FAULT RECOVERY TIME (NEGATIVE INPUT)
1.00μs
MAX4708/09 toc19
GND
V
NO_
INPUT 10V/div
GND
V
COM_
OUTPUT 5V/div
FAULT RESPONSE TIME (POSITIVE INPUT)
100ns/div
MAX4708/09 toc20
V
NO_
INPUT 10V/div
GND
V
COM_
OUTPUT 5V/div
GND
FAULT RESPONSE TIME (NEGATIVE INPUT)
100ns/div
MAX4708/09 toc21
GND V
NO_
INPUT 10V/div
GND V
COM_
OUTPUT 5V/div
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
_______________________________________________________________________________________ 9
Pin Descriptions
MAX4708 (Single 8-to-1 Mux) MAX4709 (Dual 4-to-1 Mux)
PIN
NAME
FUNCTION
1 A0 Address Bit 0
2 EN Mux Enable
3V-
Negative Supply Voltage. Bypass to GND with a 0.1µF capacitor.
4
Channel Input 1
5
Channel Input 2
6
Channel Input 3
7
Channel Input 4
8
Analog Output
9
Channel Input 8
10
Channel Input 7
11
Channel Input 6
12
Channel Input 5
13 V+
Positive Supply Voltage. Bypass to GND with a 0.1µF capacitor.
14
Ground
15 A2 Address Bit 2
16 A1 Address Bit 1
PIN
NAME
FUNCTION
1 A0 Address Bit 0
2 EN Mux Enable
3V-
Negative Supply Voltage. Bypass to GND with a 0.1µF capacitor.
4
Channel Input 1A
5
Channel Input 2A
6
Channel Input 3A
7
Channel Input 4A
8
Mux Output A
9
Mux Output B
10
Channel Input 4B
11
Channel Input 3B
12
Channel Input 2B
13
Channel Input 1B
14 V+
Positive Supply Voltage. Bypass to GND with a 0.1µF capacitor.
15
Ground
16 A1 Address Bit 1
Truth Tables
MAX4708 (Single 8-to-1 Mux) MAX4709 (Dual 4-to-1 Mux)
A2 A1 A0 EN
ON SWITCH
XXX0 None
0001 NO1
0011 NO2
0101 NO3
0111 NO4
1001 NO5
1011 NO6
1101 NO7
1111 NO8
A1 A0 EN COMA COMB
X X 0 None None
0 0 1 NO1A NO1B
0 1 1 NO2A NO2B
1 0 1 NO3A NO3B
1 1 1 NO4A NO4B
X = Don’t care.
NO1
NO2
NO3
NO4
COM
NO8
NO7
NO6
NO5
GND
NO1A
NO2A
NO3A
NO4A
COMA
COMB
NO4B
NO3B
NO2B
NO1B
GND
MAX4708/MAX4709
Detailed Description
Several unique features differentiate the MAX4708/ MAX4709 from traditional fault-protected multiplexers. First, instead of the three series FETs utilized in older designs, the MAX4708/MAX4709 design employs two parallel FETs for lower on-resistance and improved flat­ness. Second, older devices limited the range of signal amplitudes the switch could pass by as much as 3V below the supply rails. The MAX4708/MAX4709 feature rail-to-rail signal handling that allows the devices to transmit signals with amplitudes at or slightly beyond the supply rails. Finally, in former designs (MAX4508/ MAX4509), when a fault occurred, the devices clamped and held the output voltage at the appropriate supply rail until the fault was removed. Instead, the MAX4708/MAX4709 now disconnect COM_ from NO_ during a fault condition, making COM_ a high-imped­ance output as long as the fault is present. Operation is identical for both positive and negative fault polarities.
When the NO_ voltage ranges beyond supply rails (fault condition), the NO_ input becomes high imped­ance, regardless of the switch state or load resistance. If power is removed, and the fault voltage is still pre­sent, the NO_ terminals remain high impedance. The fault voltage can be up to ±40V, with V+ = V- = 0.
The COM_ pins are not fault protected. Limit any volt­age sources connected to COM_ to the supply rails.
Figure 1 shows the internal construction of a single nor­mally open (NO) switch, with the analog signal paths shown in bold. The parallel combination of N-channel FET N1 and P-channel FET P1 form the analog switch. During normal operation, these FETs are driven on and off simultaneously according to the control voltages on A_. During a fault condition, both FETs turn off.
NO_ Input Voltage
The maximum allowable input voltage for safe operation depends on whether supplies are on or off, and the load configuration on COM_. If COM_ is referred to a voltage other than ground, but within the supplies, V
NO_
can range higher or lower than the supplies, provided the absolute value of |V
NO_
- V
COM_
| is less than 40V.
For example, with V+ = V- = 0, if the load is referred to +10V at COM_, then the NO_ voltage range can be from +50V to -30V. If the supplies are ±15V and COM_ is refer­enced to ground through a load, the maximum NO_ volt­age is ±36V. If the supplies are off and the COM output is referenced to ground, the maximum NO_ voltage is ±40V.
Normal Operation
Two comparators continuously compare the voltage on NO_ with V+ and V- supply voltages. When the signal
on NO_ ranges between V+ and V-, the multiplexer operates normally, with FETs N1 and P1 turning on and off in response to the control signals on A_ (Figure 1). When the switch state is on, the parallel combination of N1 and P1 forms a low-value resistor between NO_ and COM_ so that signals pass equally well in either direc­tion. When the switch state is off, both NO_ and COM_ are high-impedance inputs.
Fault Conditions
A fault condition occurs when the voltage at any NO_ input exceeds the supply rail. At this point, the output of one of the two fault comparators goes high, effectively turning OFF both FETs N1 and P1. With the two FETs in the OFF position, both the switch input (NO_) and the out­put (COM_) go into a high-impedance state. They remain high impedance regardless of the state of the control volt­ages in A_ and EN, until the fault is removed. The input voltage must not exceed the absolute maximum rating at any moment (see the
Absolute Maximum Ratings
section).
A fault condition on the selected channel drives COM_ to a high-impedance state. However, the fault condition does not affect the performance of other channels. Therefore, while the selected channel is in fault condi­tion, selecting another channel or operating under nor­mal condition, drives COM_ out of high impedance.
Transient Fault Condition
When a fast rising or falling transient on NO_ exceeds V+ or V-, there is a 100ns delay before the fault protec­tion turns on (see the
Typical Operating Charac-
teristics
, Fault Response Time). COM_ follows NO_ until the fault protection turns on. This delay is due to the switch on-resistance and circuit capacitance to ground. When the input transient returns to within the supply rails, there is a longer output recovery time (see the
Typical Operating Characteristics
, Fault Response Times). These values depend on the COM_ output resistance and capacitance. Higher COM_ output resis­tance and capacitance increase the recovery times. The delays do not depend on the fault amplitude.
COM and A_
The GND, COM_, and A_ pins are not fault protected. ESD-protection diodes internally connect A_ to both V+ and V-. If a signal on GND, COM_, or A_ exceeds V+ or V- by more than 300mV, excessive current can flow to or from the supplies, possibly damaging the device.
Logic-Level Thresholds
The logic-level thresholds are CMOS and TTL compatible with V+ = +15V and V- = -15V. Logic levels change as V+ increases (see the
Typical Operating Characteristics
,
Logic-Level Threshold Voltage vs. Supply Voltage.)
Fault-Protected, Single 8-to-1/ Dual 4-to-1 Multiplexers
10 ______________________________________________________________________________________
Applications Information
Ground
V+ and GND power the internal logic and logic-level trans­lators. The logic-level translators convert the logic-level inputs to V+ and V- to drive the gates of the internal FETs. In this design, there is no galvanic connection inside the MAX4708/MAX4709 between the analog signal paths and GND. ESD-protection diodes connect A_ to V+ and V-.
Supply Current Reduction
Driving the logic signals rail-to-rail from 0 to +15V or
-15V to +15V reduces the current consumption from 370µA (typ) to 200µA (typ) (see the
Electrical Charac-
teristic
s table, Power Supplies).
Power Supplies
The MAX4708/MAX4709 operate with bipolar supplies between ±4.5V and ±20V. The V+ and V- supplies need not be symmetrical, but V+ - V- cannot exceed the 44V absolute maximum rating.
The MAX4708/MAX4709 operate from single supplies between +9V and +36V when V- is connected to GND.
Chip Information
PROCESS: CMOS
SUBSTRATE INTERNALLY CONNECTED TO V+
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
______________________________________________________________________________________ 11
NORMALLY OPEN SWITCH CONSTRUCTION
COM_
P1
N1
ON
LOW
FAULT
HIGH
FAULT
V+
NO_
A_
GND
ESD DIODES
V-
MAX4708 MAX4709
Pin Configurations/Functional Diagrams (continued)
Figure 1. Functional Diagram
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages
.
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
16 Narrow SO —
21-0041
16 Wide SO —
21-0042
16 Plastic DIP —
21-0043
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/ Dual 4-to-1 Multiplexers
12 ______________________________________________________________________________________
Test Circuits/Timing Diagrams
50%
t
TRANS
tR < 20ns t
F
< 20ns
V
OUT
+3V
0V
V
NO1
0V
V
NO8
LOGIC INPUT V
A_
SWITCH OUTPUT
V
OUT
GND
V+
A1
V-
A2
A0
EN
NO1
NO2–NO7
NO8
COM
+10V
-10V
50Ω
MAX4708
R
L
C
L
R
L
C
L
V
OUT
GND
V+
A0
V-
A1
EN
NO1B
NO1A–NO4A
NO4B
COMB
+10V
50Ω
MAX4709
90%
90%
t
TRANS
ON
-10V
+2.4V
+2.4V
Figure 2. Address Transition Time
50%
t
OFF(EN)
tR < 20ns t
F
< 20ns
+3V
0V
0V
LOGIC INPUT V
EN
SWITCH OUTPUT V
OUT
V
OUT
GND
V+
A1
V-
A0
A2
EN
NO1
NO2–NO8
COM
+10V
50Ω
MAX4708
R
L
C
L
R
L
C
L
90%
10%
t
ON(EN)
V
OUT
GND
V+
A1
V-
A0
EN
NO1B
NO1A–NO4A
NO2B–NO4B,
COMA
COMB
+10V
50Ω
MAX4709
V
EN
V
EN
Figure 3. Enable Switching Time
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
______________________________________________________________________________________ 13
50%
t
OPEN
tR < 20ns t
F
< 20ns
+5V
+3V
0V
LOGIC INPUT V
A
SWITCH OUTPUT V
OUT
V
OUT
GND
V+
A0
V-
A1
A2
EN
NO1–NO8
COM
+10V
50Ω
MAX4708
1kΩ
35pF
80%
+2.4V
0V
V
A
V
EN
Figure 4. Break-Before-Make Interval
Test Circuits/Timing Diagrams (continued)
ΔV
OUT
+3V
0V
LOGIC INPUT V
EN
V
OUT
GND
V+
A1
V-
A0
A2
EN
COM
MAX4708
1nF
V
OUT
NO
CHANNEL
SELECT
R
S
V
S
ONOFF OFF
ΔV
OUT
IS THE MEASURED VOLTAGE DUE TO CHARGE TRANSFER
ERROR V
CTE
WHEN THE CHANNEL TURNS OFF.
V
CTE
= ΔV
OUT X CL
V
EN
Figure 5. Charge Injection
V
OUT
GND
V+
A1
V-
A0
A2
NO8
COM
MAX4708
NO1
R
S
= 50Ω
V
IN
EN
10nF
R
L
75Ω
OFF-ISOLATION = 20log
V
OUT
V
IN
10nF
Figure 6. Off-Isolation
V
OUT
GND
V+
A1
V-
A0
A2
NO8
COM
MAX4708
NO2
R
G
= 50Ω
V
IN
EN
10nF
R
L
75Ω
10nF
NO1
R 1kΩ
CROSSTALK = 20log
V
OUT
V
IN
Figure 7. Crosstalk
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/ Dual 4-to-1 Multiplexers
14 ______________________________________________________________________________________
Test Circuits/Timing Diagrams (continued)
GND
V+
A2
V-
A1
A0
NO8
MAX4708
CHANNEL
SELECT
NO1
COM
EN
1MHz
CAPACITANCE
ANALYZER
f = 1MHz
Figure 8. NO_, COM_ Capacitance
+25V
-25V
-15V
+15V
V
COM_
V
NO
_
Figure 9. Transient Behavior of Fault Condition
Functional Diagrams/Truth Tables
DECODERS/DRIVERS
COM
NO1
NO2 NO3
NO4
NO5
NO6 NO7
NO8
A0 A1 A2 EN
V+ V- GND
MAX4708
A0A1A2 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
LOGIC 0 VAL ≤ +0.8V, LOGIC 1 VAH ≥ +2.4V
MAX4708
DECODERS/DRIVERS
COMA
NO1A
NO2A NO3A
NO4A
A0 A1 EN
V+ V- GND
MAX4709
COMB
NO1B
NO2B NO3B
NO4B
A0A1 EN ON SWITCH
X
0
0
1
1
X
0
1
0
1
0
1
1
1
1
NONE
1
2
3
4
LOGIC 0 VAL ≤ +0.8V, LOGIC 1 VAH ≥ +2.4V
MAX4709
MAX4708/MAX4709
Fault-Protected, Single 8-to-1/
Dual 4-to-1 Multiplexers
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
15
© 2008 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
DATE
DESCRIPTION
PAGES
CHANGED
0 9/02 Initial release ⎯
1 12/08
Added chip process and packaging information; changed fault conditions information
10, 11
REVISION
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