The Intersil HI-539 is a monolithic, 4-Channel, differential
multiplexer. Two digital inputs are provided for channel
selection, plus an Enable input to disconnect all channels.
Performance is guaranteed for each channel over the
voltage range ±10V, but is optimized for low level differential
signals. Leakage current, for example, which varies slightly
with input voltage, has its distribution centered at zero input
volts.
In most monolithic multiplexers, the net differential offset due
to thermal effects becomes significant for low level signals.
This problem is minimized in the HI-539 by symmetrical
placement of critical circuitry with respect to the few heat
producing devices.
Supply voltages are ±15V and power consumption is only
2.5mW.
Ordering Information
TEMP.
PART NUMBER
RANGE (oC)PACKAGE
HI1-0539-50 to 7516 Ld CERDIPF16.3
HI1-0539-8-55 to 12516 Ld CERDIPF16.3
HI3-0539-50 to 7516 Ld PDIPE16.3
HI4P0539-50 to 7520 Ld PLCCN20.35
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operationofthe
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTE:
1. θJA is measured with the component mounted on an evaluation PC board in free air.
2. See Figures 2B, 2C, 2D. The condition ±10V means:
l
S(OFF)
and I
D(OFF)
:
(VS = +10V, VD = -10V), then
(VS = -10V, VD = +10V)
I
: (+10V, then -10V)
D(ON)
3. ∆VOS(Exclusive of thermocouple effects) = rON∆I
4. VlN = 1kHz, 15V
on all but the selected channel. See Figure 7.
P-P
D(ON)
+ I
D(ON)∆rON
. See Applications section for discussion of additional VOS error.
5. Calculated from typical Single-Ended Crosstalk performance.
T est Cir cuits and Waveforms
100µA
V
2
Unless Otherwise Specified TA = 25oC, V+ = +15V, V - = -15V, VAH = 4V and VAL = 0.8V
VIN = 0V
800
700
OUTIN
V
V
IN
HI-539
rON =
2
100µA
600
ON RESISTANCE (Ω)
500
-250255075100125
-50
TEMPERATURE (
o
C)
FIGURE 1A. TEST CIRCUITFIGURE 1B. ON RESISTANCE vs TEMPERATURE
900
125oC
800
700
600
ON RESISTANCE (Ω)
500
400
-12
-10 -8-6 -4-20248 10612
25oC
-55oC
ANALOG INPUT (V)
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
ON RESISTANCE (kΩ)
0.9
0.8
0.7
0.6
0.5
57911131517
SUPPLY VOLTAGE (±V)
VIN = 0V
FIGURE 1C. ON RESISTANCE vs ANALOG INPUT VOLTAGEFIGURE 1D. ON RESISTANCE vs SUPPLY VOLTAGE
FIGURE 1. ON RESISTANCE
4
HI-539
T est Cir cuits and Waveforms
10
I
D(ON)
1
LEAKAGE CURRENT (nA)
25
5075100125
I
D(OFF)
TEMPERATURE (
Unless Otherwise Specified TA = 25oC, V+ = +15V, V - = -15V, VAH = 4V and VAL = 0.8V (Continued)
= I
S(OFF)
o
C)
±10V
FIGURE 2A. LEAKAGE CURRENT vs TEMPERATUREFIGURE 2B. I
†
HI-539
OUT A
I
A
S(OFF)
±10V
±
10V
A
0
A
1
EN
0.8V
±
10V
HI-539†
EN
A
0
A
1
† Similar Connection For Side “B”
TEST CIRCUIT (NOTE 6)
D(OFF)
HI-539†
A
0
EN
A
1
OUT A
OUT A
4V
0.8V
I
A
D(OFF)
±
10V
A
I
D(ON)
±10V
†Similar Connection For Side “B”
FIGURE 2C. I
TEST CIRCUIT (NOTE 6)FIGURE 2D. I
S(OFF)
†Similar Connection For Side “B”
TEST CIRCUIT (NOTE 6)
D(ON)
NOTE:
6. Three measurements = ±10V,10V, and 0V.
±
FIGURE 2. LEAKAGE CURRENT
+15V/+10V
14
12
10
8
6
4
I+ SUPPLY CURRENT (mA)
2
0
100Hz
1kHz10kHz100kHz1MHz 3MHz 10MHz
FUNCTIONAL LIMIT
V
SUPPLY
V
SUPPLY
TOGGLE FREQUENCY
= ±15V
= ±10V
50Ω
V
A
HIGH = 4.0V
LOW = 0V
V
A
50% DUTY CYCLE
A
1
HI-539
A
0
5V
EN
GND
†Similar Connection For Side “B”
A
V+
IN 1A
†
IN 2A
IN 3A
IN 4A
OUT A
V-
A
+I
-I
-15V/-10V
FIGURE 3A. SUPPLY CURRENT vs TOGGLE FREQUENCYFIGURE 3B. TEST CIRCUIT
FIGURE 3. DYNAMIC SUPPLY CURRENT
SUPPLY
SUPPLY
+10V/+5V
-10V/-5V
10MΩ
14pF
5
HI-539
T est Cir cuits and Waveforms
320
300
280
260
240
ACCESS TIME (ns)
220
200
3
456789101112131415
LOGIC LEVEL (HIGH) (V)
Unless Otherwise Specified TA = 25oC, V+ = +15V, V - = -15V, VAH = 4V and VAL = 0.8V (Continued)
A
1
A
0
50Ω
V
A
5V
EN
HI-539
GND
FIGURE 4A. ACCESS TIME vs LOGIC LEVEL (HIGH)FIGURE 4B. TEST CIRCUIT
= 4V
V
AH
50%
ADDRESS
DRIVE (V
)
A
0V
VA INPUT
2V/DIV.
S1 ON
+15V
V+
IN 1A
IN 2A,
IN 3A
IN 4A
OUT A
V-
-15V
±
10V
±10V
kΩ
50
10
pF
+10V
10%
t
A
OUTPUT
-10V
200ns/DIV.
OUTPUT
5V/DIV.
S4 ON
FIGURE 4C. MEASUREMENT POINTSFIGURE 4D. WAVEFORMS
FIGURE 4. ACCESS TIME
+15V
0V
VAH = 4V
50%50%
t
ADDRESS
DRIVE (V
OPEN
)
A
OUTPUT
HI-539†
A
1
A
0
EN
5V
50ΩV
A
IN 2, IN 3A
GND
V+
IN 1A
IN 4A
OUT A
V-
-15V
†Similar connection for side “B”
700
+5V
V
OUT
Ω
12.5pF
FIGURE 5A. MEASUREMENT POINTSFIGURE 5B. TEST CIRCUIT
6
HI-539
T est Cir cuits and Waveforms
VAH = 4V
Unless Otherwise Specified TA = 25oC, V+ = +15V, V - = -15V, VAH = 4V and VAL = 0.8V (Continued)
VA INPUT
2V/DIV.
S1 ON
100ns/DIV.
S4 ON
OUTPUT
1V/DIV.
FIGURE 5C. WAVEFORMS
FIGURE 5. BREAK-BEFORE-MAKE DELAY
+15V
HI-539
V+
†
IN 1A
+10V
50%
90%
t
ON(EN)
50% ENABLE DRIVE (V
0V
OUTPUT
10%
0V
t
OFF(EN)
)
A
V
A
50
Ω
A
A
EN
1
0
GND
IN 2A THRU
†Similar connection for side “B”
FIGURE 6A. MEASUREMENT POINTSFIGURE 6B. TEST CIRCUIT
ENABLE
DRIVE
2V/DIV.
DISABLED
ENABLED
(S1 ON)
OUTPUT
2V/DIV.
IN 4A
OUT A
V-
-15V
700
V
OUT
Ω
12.5pF
100ns/DIV.
FIGURE 6C. WAVEFORMS
FIGURE 6. ENABLE DELAYS
7
HI-539
T est Cir cuits and Waveforms
HI-539
1kHz,
15V
P-P
350Ω
†AD606 or BB3630, for Example
FIGURE 7A. SINGLE-ENDED CROSSTALK TEST CIRCUITFIGURE 7B. DIFFERENTIAL CROSSTALK TEST CIRCUIT
Application Information
Unless Otherwise Specified TA = 25oC, V+ = +15V, V - = -15V, VAH = 4V and VAL = 0.8V (Continued)
INSTRUMENTATION
AMPLIFIER
G = 1000
+
†
-
1kHz,
15V
HI-539
350Ω
350Ω
P-P
INSTRUMENTATION
AMPLIFIER
G = 1000
+
-
†AD606 or BB3630, for example
FIGURE 7. CROSSTALK
Coaxial cable is not suitable for lo w le vel signals because the
two conductors (center and shield) are unbalanced. Also,
General
The Hl-539 accepts inputs in the range -15V to +15V, with
performance guaranteed over the ±10V range. At these
higher levelsof analog inputvoltage it is comparable to the Hl509, and is plug-in compatiblewith that device (as wellas the
Hl-509A). Howev er, as mentioned earlier, the Hl-539 was
designed to introduce minimum error when switchinglow level
inputs.
Special care is required in working with these low level
signals. The main concern with signals below 100mV is that
noise, offset voltage, and other aberrations can represent a
large percentage error. A shielded differential signal path is
essential to maintain a noise level below 50µV
RMS
.
Low Level Signal Transmission
The transmission cable carrying the transducer signal is critical
in a low level system. It should be as short as practical and
rigidly supported. Signal conductors should be tightly twisted
for minimum enclosed area to guard against pickup of
electromagnetic interference, and the twisted pair should be
shielded against capacitively coupled (electrostatic)
interference. A braided wire shield ma y be satisfactory, but a
lapped foil shield is better since it allows only
leakage capacitance to ground per foot. A ke y requirement f or
the transmission cable is that it presents a balanced line to
sources of noise interference. This means an equal series
1
/10 as much
ground loops are produced if the shield is grounded at both
ends by standard BNC connectors. If coax must be used, carry
the signal on the center conductors of two equal-length cables
whose shields are terminated only at the transducer end. As a
general rule, terminate (ground) the shield at one end only ,
preferably at the end with greatest noise interference. This is
usually the transducer end for both high and low le v el signals .
Watch Small∆V Errors
Printed circuit traces and short lengths of wire can add
substantial error to a signal even after it has traveled
hundreds of feet and arrived on a circuit board. Here, the
small voltage drops due to current flow through connections
of a fewmilliohms must be considered, especially to meet an
accuracy requirement of 12 bits or more.
Table 1 is a useful collection of data for calculating theeffect
of these short connections. (Proximity to a ground plane will
lower the values of inductance.)
As an example, suppose the Hl-539 is feeding a 12-bit
converter system with an allowable error of ±
(±1.22mV). lf the interface logic draws 100mA from the 5V
supply, this current will produce 1.28mV across 6 inches of
#24 wire; more than the error budget. Obviously, this digital
current must not be routed through any portion of theanalog
ground return network.
1
/2 LSB
impedance in each conductor plus an equally distributed
impedance from each conductor to ground. The result should
be signals equal in magnitude but opposite in phase at any
transverse plane. Noise will be coupled in phase to both
conductors, and may be rejected as common-mode voltage b y
a differential amplifier connected to the multiplexer output.
The input bias current for any DC-coupled amplifier must
have an external path back to the amplifier’s power supply.
No such path exists in Figure 8A, and consequently the
amplifier output will remain in saturation.
A single large resistor (1MΩ to10MΩ) from eithersignal line
to powersupply common will provide the required path, but a
resistor on each line is necessary to preserve accuracy. A
single pair of these bias current resistors on the HI-539
output may be used if their loading effect can be tolerated
(each formsa voltage divider with r
). Otherwise,a resistor
ON
pair on each input channel of the multiplexer is required.
The use of bias current resistors is acceptable only if one is
confident that the sum of signal plus common-mode voltage
will remain within the input range of the multiplexer/amplifier
combination.
Another solution is to simply run a third wire from the low
side of the signal source, as in Figure 8B. This wire assures
a low common-mode voltage as well as providing the path
for bias currents. Making the connection near the multiplexer
will save wire, but it will also unbalance the line and reduce
the amplifier's common-mode rejection.
Differential Offset,∆V
OS
There are two major sources of ∆VOS. That part due to the
expression(r
ON∆lD(ON)+lD(ON)∆rON
) becomes significant
with increasing temperature, as shown in the Electrical
Specifications tables. The other source of offset is the
thermocouple effects due to dissimilar materials in the signal
path. These include silicon, aluminum, tin, nickel-iron and
(often) gold, just to exit the package.
For the thermocouple effects in the package alone, the
constraint on ∆V
may be stated in terms of a limit on the
OS
difference in temperature for package pins leading to any
channel of the Hl-539. For example, a difference of 0.13
o
C
produces a 5µV offset. Obviously, this ∆T effect can
dominate the ∆V
parameter at any temperature unless
OS
care is taken in mounting the Hl-539 package.
Temperature gradients across the Hl-539 package should be
held to a minimum in critical applications. Locate the Hl-539
far from heat producing components, with any air currents
flowing lengthwise across the package.
9
HI-539
“FLOATING”
SOURCE
HI-539
r
ON
r
ON
V+
+
-
V-
FIGURE 8A.
1M TO 10M
POWER SUPPLY
COMMON
HI-539
r
ON
r
ON
POWER SUPPLY
COMMON
V+
+
-
V-
NOTE: The amplifier in Figure 8A is unusable because its bias currents cannot return to the power supply. Figure 8B shows two alternative paths
for these bias currents: either a pair of resistors, or (better) a third wire from the low side of the signal source.
FIGURE 8B.
10
Die Characteristics
HI-539
DIE DIMENSIONS:
92 mils x 100 mils
METALLIZATION:
Type: AlCu
Thickness: 16k
Å ±2kÅ
SUBSTRATE POTENTIAL (NOTE):
-V
SUPPLY
NOTE: The substrate appears resistive to the -V
conductor at -V
SUPPLY
potential.
Metallization Mask Layout
V-ENA
PASSIVATION:
Type: Nitride Over Silox
Nitride Thickness: 3.5k
Å ±1kÅ
Silox Thickness: 12kű2.0kÅ
WORST CASE CURRENT DENSITY:
5
2.54 x 10
A/cm2 at 20mA
TRANSISTOR COUNT:
236
PROCESS:
CMOS-DI
terminal, therefore it may be left floating (Insulating Die Mount) or it may be mounted on a
SUPPLY
HI-539
A
0
1
GNDV+
IN1A
IN2A
OUTBIN4BIN4AOUTAIN3A
IN1B
IN2B
IN3B
All Intersil semiconductor products are manufactured, assembled and tested under ISO9000 quality systems certification.
Intersil semiconductor products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see web site http://www.inter sil.com
11
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