INTERSIL EL8188

EL8188
¬
Data Sheet
May 29, 2009
Micropower Single Supply Rail-to-Rail
Input-Output Precision Op Amp
Features
The EL8188 is a precision low power, operational amplifier.
The device is optimized for single supply operation between
2.4V to 5.5V. This enables operation from one lithium cell or
two Ni-Cd batteries. The input range includes both positive
and negative rail.
• 1mV Max Offset Voltage
The EL8188 draws minimal supply current (55µA) while
meeting excellent DC-accuracy, noise, and output drive
specifications.
• Rail-to-rail Input and Output
FN7467.6
• Typical 55µA Supply Current
• Typical 1pA Input Bias Current
• 266kHz Gain-bandwidth Product
• Single Supply Operation Between 2.4V to 5.5V
• Ground Sensing
• Output Sources and Sinks 26mA Load Current
Ordering Information
PART
PART NUMBER MARKING
EL8188FIZ-T7*
(Note 2)
188Z
TEMP
RANGE
(°C)
• Pb-free (RoHS compliant)
PACKAGE
(Pb-Free)
PKG.
DWG. #
-40 to +125 6 Ld WLCSP
W3x2.6C
(1.5mmx1.0mm)
BBYA
Coming Soon
EL8188FWZ-T7A*
(Note 1)
-40 to +125 6 Ld SOT-23
MDP0038
Coming Soon
EL8188FWZ-T7*
(Note 1)
BBYA
-40 to +125 6 Ld SOT-23
Coming Soon
EL8188ISZ
(Note 1)
8188ISZ
Coming Soon
EL8188ISZ-T7*
(Note 1)
8188ISZ
-40 to +125 8 Ld SOIC
MDP0027
Coming Soon
EL8188ISZ-T13*
(Note 1)
8188ISZ
-40 to +125 8 Ld SOIC
MDP0027
Applications
• Battery - or Solar-powered Systems
• 4mA to 20mA Current Loops
• Handheld Consumer Products
• Medical Devices
MDP0038
• Thermocouple Amplifiers
• Photodiode Pre-amps
-40 to +125 8 Ld SOIC
MDP0027
• pH Probe Amplifiers
Pinouts
OUT 1
V- 2
*Please refer to TB347 for details on reel specifications.
EL8188
(8 LD SO)
TOP VIEW
EL8188
(6 LD SOT-23)
TOP VIEW
6 V+
+ -
IN+ 3
DNC 1
5 DNC
IN- 2
4 IN-
IN+ 3
8 DNC
+
7 V+
6 OUT
NOTES:
V- 4
1. These Intersil Pb-free plastic packaged products employ special
Pb-free material sets, molding compounds/die attach materials,
and 100% matte tin plate plus anneal (e3 termination finish, which
is RoHS compliant and compatible with both SnPb and Pb-free
soldering operations). Intersil Pb-free products are MSL classified
at Pb-free peak reflow temperatures that meet or exceed the Pbfree requirements of IPC/JEDEC J STD-020
2. These Intersil Pb-free WLCSP and BGA packaged products
products employ special Pb-free material sets; molding
compounds/die attach materials and SnAgCu - e1 solder ball
terminals, which are RoHS compliant and compatible with both
SnPb and Pb-free soldering operations. Intersil Pb-free WLCSP
and BGA packaged products are MSL classified at Pb-free peak
reflow temperatures that meet or exceed the Pb-free requirements
of IPC/JEDEC J STD-020.
1
5 DNC
EL8188
(6 LD WLCSP)
TOP VIEW
1
2
A
DNC
OUT
B
V+
V-
C
IN-
IN+
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2004-2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
EL8188
Absolute Maximum Ratings (TA = +25°C)
Thermal Information
Supply Voltage (VS) and Pwr-up Ramp Rate . . . . . . . 5.75V, 1V/µs
Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5V
Current into IN+, IN-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA
Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . V- -0.5V to V+ +0.5V
ESD Tolerance
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3kV
Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .300V
Thermal Resistance
θJA (°C/W)
6 Ld SOT Package . . . . . . . . . . . . . . . . . . . . . . . . .
230
6 Ld WLCSP Package . . . . . . . . . . . . . . . . . . . . . . .
130
8 Ld SOIC Package . . . . . . . . . . . . . . . . . . . . . . . .
125
Ambient Operating Temperature Range . . . . . . . . .-40°C to +125°C
Storage Temperature Range . . . . . . . . . . . . . . . . . -65°C to +150°C
Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . +125°C
Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and
result in failures not covered by warranty.
IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typical values are for information purposes only. Unless otherwise noted, all tests
are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA
Electrical Specifications
V+ = 5V, V- = 0V, VCM = 2.5V, VO = 2.5V, TA = +25°C unless otherwise specified. Boldface limits apply over
the operating temperature range, -40°C to +125°C
PARAMETER
VOS
DESCRIPTION
Input Offset Voltage
TEST CONDITIONS
SOT-23
WLCSP
ΔV OS
-----------------ΔTime
Long Term Input Offset Voltage Stability
ΔV OS
---------------ΔT
Input Offset Drift vs Temperature
IB
Input Bias Current (See Figure 20)
MIN
(Note 3)
TYP
MAX
(Note 3)
UNIT
-1
0.05
+1
mV
-1.5
+1.5
mV
-1.5
+1.5
mV
-25
3
µV/Mo
1.1
µV/°C
1
-600
25
pA
600
pA
Input Noise Voltage Peak-to-Peak
f = 0.1Hz to 10Hz
2.8
µVP-P
Input Noise Voltage Density
fO = 1kHz
48
nV/√Hz
iN
Input Noise Current Density
fO = 1kHz
0.15
pA/√Hz
CMIR
Input Voltage Range
Guaranteed by CMRR test
0
CMRR
Common-Mode Rejection Ratio
VCM = 0V to 5V
80
eN
5
100
dB
75
PSRR
Power Supply Rejection Ratio
VS = 2.4V to 5.5V
80
dB
100
dB
80
AVOL
VOUT
Large Signal Voltage Gain
Maximum Output Voltage Swing
SOT-23
VO = 0.5V to 4.5V,
RL = 100kΩ to (V+ + V-)/2
100
VOL; Output low,
RL = 1kΩ to (V+ + V-)/2
2
dB
400
V/mV
100
VOL; Output low,
RL = 100kΩ to (V+ + V-)/2
VOH; Output high,
RL = 100kΩ to (V+ + V-)/2
4.994
VOH; Output high,
RL = 1kΩ to (V+ + V-)/2
4.750
V/mV
3
10
mV
130
250
mV
350
mV
4.9975
4.994
4.7
V
V
V
4.875
V
V
FN7467.6
May 29, 2009
EL8188
Electrical Specifications
V+ = 5V, V- = 0V, VCM = 2.5V, VO = 2.5V, TA = +25°C unless otherwise specified. Boldface limits apply over
the operating temperature range, -40°C to +125°C (Continued)
PARAMETER
VOUT
DESCRIPTION
Maximum Output Voltage Swing
WLCSP
TEST CONDITIONS
MIN
(Note 3)
VOL; Output low,
RL = 100kΩ to (V+ + V-)/2
VOL; Output low,
RL = 1kΩ to (V+ + V-)/2
SR
TYP
MAX
(Note 3)
UNIT
3
10
mV
130
250
mV
350
mV
VOH; Output high,
RL = 100kΩ to (V+ + V-)/2
4.991
4.997
V
VOH; Output high,
RL = 1kΩ to (V+ + V-)/2
4.750
4.875
V
Slew Rate
4.7
0.1
V
0.15
0.07
GBWP
Gain Bandwidth Product
fO = 100kHz
IS, ON
Supply Current, Enabled
SOT-23
35
55
45
65
40
ISC+
Short Circuit Output Current
RL = 10Ω to opposite supply
V/µs
0.25
V/µs
266
30
WLCSP
0.19
23
kHz
75
µA
85
µA
85
µA
95
µA
31
mA
18
ISC-
Short Circuit Output Current
RL = 10Ω to opposite supply
20
mA
26
mA
15
VS
Supply Voltage
Guaranteed by PSRR
mA
2.4
5.5
V
2.4
5.5
V
NOTE:
3. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization
and are not production tested.
3
FN7467.6
May 29, 2009
EL8188
Typical Performance Curves
VS = ±2.5V, TA = +25°C, Unless Otherwise Specified
1
80
RL ≥ 10k
VOUT = 0.2VP-P
50
VS = ±1.2
GAIN (dB)
GAIN (dB)
GAIN = 500
60
0
RL ≥ 10k
VOUT = 0.2VP-P
GAIN = 1k
70
-1
VS = ±2.5
GAIN = 200
40
GAIN = 100
GAIN = 10
30
GAIN = 5
20
10
-2
GAIN = 2
0
VS = ±1.0
-3
1k
10k
-10
100k
GAIN = 1
-20
1M
1
10
100
FREQUENCY (Hz)
10M
50
40
30
20
10
2.5
3.0
4.0
3.5
4.5
5.0
AV = -1
VCM = VDD/2
100
0
-100
-200
-0.5
5.5
0.5
SUPPLY VOLTAGE (V)
1.5
2.5
3.5
4.5
5.5
OUTPUT VOLTAGE (V)
FIGURE 3. SUPPLY CURRENT vs SUPPLY VOLTAGE
FIGURE 4. INPUT OFFSET VOLTAGE vs OUTPUT VOLTAGE
150
50
-50
80
0
60
45
PHASE
90
40
20
-150
135
GAIN
180
0
0.5
1.5
2.5
3.5
4.5
5.5
COMMON-MODE INPUT VOLTAGE (V)
FIGURE 5. INPUT OFFSET VOLTAGE vs COMMON-MODE
INPUT VOLTAGE
4
-20
10
PHASE SHIFT (°)
100
250
GAIN (dB)
NORMALIZED INPUT OFFSET VOLTAGE (µV)
100k 1M
200
INPUT OFFSET VOLTAGE (µV)
SUPPLY CURRENT (µA)
60
-250
-0.5
10k
FIGURE 2. FREQUENCY RESPONSE at VARIOUS CLOSED
LOOP GAINS
FIGURE 1. UNITY GAIN FREQUENCY RESPONSE at
VARIOUS SUPPLY VOLTAGES
0
2.0
1k
FREQUENCY (Hz)
100
1k
10k
100k
1M
FREQUENCY (Hz)
FIGURE 6. OPEN LOOP GAIN AND PHASE vs FREQUENCY
(RL = 1kΩ)
FN7467.6
May 29, 2009
EL8188
Typical Performance Curves
(Continued) VS = ±2.5V, TA = +25°C, Unless Otherwise Specified (Continued)
100
10
90
0
80
-10
-20
90
50
PHASE
40
135
30
20
180
GAIN
10
CMRR (dB)
60
PHASE SHIFT (°)
70
GAIN (dB)
ΔVCM = 1VP-P
RL = 100kΩ
AV = +1
-30
-40
-50
-60
-70
-80
0
-90
-10
10
-100
10
100
1k
10k
100k
1M
100
1k
10k
100k
1M
FREQUENCY (Hz)
FREQUENCY (Hz)
FIGURE 8. CMRR vs FREQUENCY
FIGURE 7. OPEN LOOP GAIN AND PHASE vs FREQUENCY
(RL = 100kΩ)
100
1000
10
ΔVS = 1VP-P
RL = 100kΩ
-10
AV = +1
-20
-PSRR
-40
-50
+PSRR
-60
-70
-80
10
100
VOLTAGE
1
10
CURRENT
-90
-100
10
CURRENT NOISE (pA/√Hz)
VOLTAGE NOISE (õV)
-30
1
100
1k
10k
FREQUENCY (Hz)
100k
1
1M
FIGURE 9. PSRR vs FREQUENCY
10
100
1k
10k
0.1
100k
FREQUENCY (Hz)
FIGURE 10. INPUT VOLTAGE AND CURRENT NOISE vs
FREQUENCY
20
15
VOS DRIFT (µV)
VOLTAGE NOISE (500nV/DIV)
PSRR (dB)
0
10
5
0
-5
2.8µVP-P
-10
-15 0
TIME (1s/DIV)
FIGURE 11. 0.1Hz TO 10Hz INPUT VOLTAGE NOISE
5
500
1000
1500
1800
TIME (HOURS)
FIGURE 12. VOS DRIFT (SOT-23 PACKAGE) vs TIME
FN7467.6
May 29, 2009
EL8188
Typical Performance Curves
(Continued) VS = ±2.5V, TA = +25°C, Unless Otherwise Specified (Continued)
75
85
n = 5000
n = 1500
MAX
70
75
CURRENT (µA)
CURRENT (mA)
65
MEDIAN
60
55
50
MIN
70
65
55
40
50
-20
0
20
40
60
80
100
MEDIAN
60
45
35
-40
MAX
80
MIN
45
-40
120
-20
0
FIGURE 13. SOT-23 SUPPLY CURRENT vs TEMPERATURE,
VS = ±2.5V
200
400
100
200
VOS (õV)
VOS (õV)
80
100
120
0
MEDIAN
-100
n = 1500
MAX
600
MAX
300
MEDIAN
0
-200
-400
-200
MIN
MIN
-600
-300
-20
0
20
40
60
80
100
-800
-40
120
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
TEMPERATURE (°C)
FIGURE 15. SOT-23 VOS vs TEMPERATURE, VS = ±2.5V
FIGURE 16. SOT-23 VOS vs TEMPERATURE, VS = ±1.2V
1500
1500
n = 5000
n = 5000
1000
MAX
1000
MAX
500
500
VOS (µV)
VOS (µV)
60
800
n = 1500
0
MEDIAN
-500
0
MEDIAN
-500
-1000
-1500
-40
40
FIGURE 14. WLCSP SUPPLY CURRENT vs TEMPERATURE,
VS = ±2.5V
400
-400
-40
20
TEMPERATURE (°C)
TEMPERATURE (°C)
MIN
-20
0
20
40
60
80
TEMPERATURE (°C)
-1000
100
120
FIGURE 17. WLCSP VOS vs TEMPERATURE, VS = ±2.5V
6
-1500
-40
MIN
-20
0
20
40
60
80
TEMPERATURE (°C)
100
120
FIGURE 18. WLCSP VOS vs TEMPERATURE, VS = ±1.2V
FN7467.6
May 29, 2009
EL8188
Typical Performance Curves
160
(Continued) VS = ±2.5V, TA = +25°C, Unless Otherwise Specified (Continued)
n = 1500
140
MAX
100
IBIAS -(pA)
IBIAS + (pA)
120
80
60
MEDIAN
40
20
MIN
0
-20
-40
-20
0
20
40
60
80
100
120
250
n = 1500
230
210
190
170
150
130
110
90
70
50
30
10
-10
-40 -20
0
FIGURE 19. IBIAS+ vs TEMPERATURE, VS = ±2.5V
20
40
60
80
100
120
130
125
MAX
n = 1500
120
120
115
115
PSRR (dB)
CMRR (dB)
MIN
FIGURE 20. IBIAS- vs TEMPERATURE, VS = ±2.5V
130
110
105
MEDIAN
100
110
MEDIAN
105
95
90
MIN
85
80
-40
MAX
n = 1500
100
95
-20
0
20
40
60
80
MIN
90
100
85
-40
120
-20
0
40
60
80
100
120
FIGURE 22. PSRR vs TEMPERATURE ±1.5V TO ±2.5V
FIGURE 21. CMRR vs TEMPERATURE, V+ = ±2.5V, ±1.5V
4.9984
4.90
n = 1500
n = 1500
4.9982
4.89
4.9980
MAX
MAX
4.9978
VOUT (V)
4.88
4.87
MEDIAN
4.86
4.9976
4.9974
MEDIAN
4.9972
4.9970
4.9968
4.85
MIN
4.9966
MIN
4.84
-40
20
TEMPERATURE (°C)
TEMPERATURE (°C)
VOUT (V)
MEDIAN
TEMPERATURE (°C)
TEMPERATURE (°C)
125
MAX
4.9964
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 23. VOUT HIGH vs TEMPERATURE, VS = ±2.5V, RL = 1k
7
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 24. VOUT HIGH vs TEMPERATURE, VS = ±2.5V,
RL = 100k
FN7467.6
May 29, 2009
EL8188
Typical Performance Curves
190
(Continued) VS = ±2.5V, TA = +25°C, Unless Otherwise Specified (Continued)
5.0
n = 1500
MAX
4.4
160
VOUT (mV)
VOUT (mV)
MAX
4.6
170
MEDIAN
150
140
MIN
MEDIAN
4.2
4.0
MIN
3.8
130
3.6
120
3.4
110
3.2
100
n = 1500
4.8
180
3.0
-40
-20
0
20
40
60
80
100
-40
120
-20
TEMPERATURE (°C)
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 26. VOUT LOW vs TEMPERATURE, VS = ±2.5V,
RL = 100k
FIGURE 25. VOUT LOW vs TEMPERATURE, VS = ±2.5V,
RL = 1k
510
n = 1500
MAX
460
AVOL (V/mV)
410
360
MEDIAN
310
260
MIN
210
160
-40
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 27. AVOL vs TEMPERATURE, RL = 100k, VO = ±2V @ VS = ±2.5V
8
FN7467.6
May 29, 2009
EL8188
Pin Descriptions
8 LD SOIC
SOT-23 PIN 6 Ld WLCSP
EQUIVALENT
PIN NUMBER NUMBER PIN NUMBER PIN NAME
CIRCUIT
1, 5
DNC
DESCRIPTION
Do Not Connect; Internal connection - Must be left floating.
2
4
C1
IN-
Circuit 1
Amplifier’s inverting input
3
3
C2
IN+
Circuit 1
Amplifier’s non-inverting input
4
2
B2
V-
Circuit 3
Negative power supply
8
5
A1
DNC
6
1
A2
OUT
Circuit 2
Amplifier’s output
7
6
B1
V+
Circuit 3
Positive power supply
Do not connect. Pin must be left floating.
V+
IN-
V+
CAPACITIVELY
COUPLED
ESD CLAMP
OUT
IN+
V-
VCIRCUIT 1
V+
VCIRCUIT 2
Application Information
Introduction
The EL8188 is a rail-to-rail input and output (RRIO),
micro-power, precision, single supply op amp. This amplifier
is designed to operate from single supply (2.4V to 5.5V) or
dual supply (±1.2V to ±2.75V) while drawing only 55µA of
supply current.The device achieves rail-to-rail input and
output operation while eliminating the drawbacks of many
conventional RRIO op amps.
Rail-to-Rail Input
The PFET input stage of the EL8188 has an input
common-mode voltage range that includes the negative and
positive supplies without introducing offset errors or
degrading performance like some existing rail-to-rail input op
amps. Many rail-to-rail input stages use two differential input
pairs: a long-tail PNP (or PFET) and an NPN (or NFET).
Severe penalties result from using this topology. As the input
signal moves from one supply rail to the other, the op amp
switches from one input pair to the other causing changes in
input offset voltage and an undesired change in the input
offset current’s magnitude and polarity.
The EL8188 achieves rail-to-rail input performance without
sacrificing important precision specifications and without
degrading distortion performance. The EL8188's input offset
voltage exhibits a smooth behavior throughout the entire
common-mode input range.
Rail-to-Rail Output
A pair of complementary MOSFET devices achieves rail-to-rail
output swing. The NMOS sinks current to swing the output in
the negative direction, while the PMOS sources current to
9
CIRCUIT 3
swing the output in the positive direction. The EL8188 with a
100kΩ load swings to within 3mV of the supply rails.
Results of Over-Driving the Output
Caution should be used when over-driving the output for long
periods of time. Over-driving the output can occur in three
ways:
1. The input voltage times the gain of the amplifier exceeds the
supply voltage by a large value.
2. The output current required is higher than the output stage
can deliver.
3. Operating the device in Slew Rate Limit. These conditions
can result in a shift in the Input Offset Voltage (VOS) as
much as 1µV/hr of exposer under these condition.
IN+ and IN- Input Protection
In addition to ESD protection diodes to each supply rail, the
EL8188 has additional back-to-back protection diodes across
the differential input terminals (see “Circuit 1” diagram on
page 8). If the magnitude of the differential input voltage
exceeds the diode’s VF, then one of these diodes will conduct.
For elevated temperatures, the leakage of the protection
diodes (Circuit 1 pin description table) increases, resulting in
the increase in Ibias as seen in Figures 19 and 20.
Usage Implications
If the input differential voltage is expected to exceed 0.5V, an
external current limiting resistor must be used to ensure the
input current never exceeds 5mA. For noninverting unity gain
applications the current limiting can be via a series IN+ resistor,
or via a feedback resistor of appropriate value. For other gain
configurations, the series IN+ resistor is the best choice, unless
FN7467.6
May 29, 2009
EL8188
the feedback (RF) and gain setting (RG) resistors are both
sufficiently large to limit the input current to 5mA.
Large differential input voltages can arise from several
sources:
1) During open loop (comparator) operation. The IN+ and INinput voltages don’t track.
2) When the amplifier is disabled but an input signal is still
present. An RL or RG to GND keeps the IN- at GND, while
the varying IN+ signal creates a differential voltage. Mux
Amp applications are similar, except that the active channel
VOUT determines the voltage on the IN- terminal.
3) When the slew rate of the input pulse is considerably
faster than the op amp’s slew rate. If the VOUT can’t keep up
with the IN+ signal, a differential voltage results, and visible
distortion occurs on the input and output signals. To avoid
this issue, keep the input slew rate below 0.2V/µs, or use
appropriate current limiting resistors.
Proper Layout Maximizes Precision
To achieve the optimum levels of high input impedance (i.e.,
low input currents) and low offset voltage, care should be
taken in the circuit board layout. The PC board surface must
remain clean and free of moisture to avoid leakage currents
between adjacent traces. Surface coating of the circuit board
will reduce surface moisture and provide a humidity barrier,
reducing parasitic resistance on the board. When input
leakage current is a paramount concern, the use of guard
rings around the amplifier inputs will further reduce leakage
currents. Figure 28 shows a guard ring example for a unity
gain amplifier that uses the low impedance amplifier output
at the same voltage as the high impedance input to eliminate
surface leakage. The guard ring does not need to be a
specific width, but it should form a continuous loop around
both inputs. For further reduction of leakage currents, mount
components to the PC board using Teflon standoffs.
HIGH IMPEDANCE INPUT
V+
Output Current Limiting
The EL8188 has no internal current-limiting circuitry. If the
output is shorted, it is possible to exceed the “Absolute
Maximum Rating” for “operating junction temperature”,
potentially resulting in the destruction of the device.
IN
Power Dissipation
It is possible to exceed the +150°C maximum junction
temperature (TJMAX) under certain load and power-supply
conditions. It is therefore important to calculate TJMAX for all
applications to determine if power supply voltages, load
conditions, or package type need to be modified to remain in
the safe operating area. These parameters are related as
follows:
T JMAX = T MAX + ( θ JA × PD MAX )
(EQ. 1)
FIGURE 28. GUARD RING EXAMPLE FOR UNITY GAIN
AMPLIFIER
Typical Applications
GENERAL
PURPOSE
COMBINATION
pH PROBE
V+
+
EL8188
V-
+
3V
COAX
where PDMAX is calculated using:
FIGURE 29. pH PROBE AMPLIFIER
V OUTMAX
PD MAX = V S × I SMAX + ( V S - V OUTMAX ) × ---------------------------R
L
(EQ. 2)
where:
• TMAX = Maximum ambient temperature
• θJA = Thermal resistance of the package
• PDMAX = Maximum power dissipation of the amplifier
• VS = Supply voltage
• IMAX = Maximum supply current of the amplifier
A general-purpose combination pH probe has extremely
high output impedance typically in the range of 10GΩ to
12GΩ. Low loss and expensive Teflon cables are often used
to connect the pH probe to the meter electronics. Figure 29
details a low-cost alternative solution using the EL8188 and
a low-cost coax cable. The EL8188 PMOS high impedance
input senses the pH probe output signal and buffers it to
drive the coax cable. Its rail-to-rail input nature also
eliminates the need for a bias resistor network required by
other amplifiers in the same application.
• VOUTMAX = Maximum output voltage swing of the
application
• RL = Load resistance
10
FN7467.6
May 29, 2009
EL8188
R4
100kΩ
R3
10kΩ
R2
K TYPE
THERMOCOUPLE
10kΩ
V+
+
EL8188
V-
410µV/°C
+
5V
R1
100kΩ
FIGURE 30. THERMOCOUPLE AMPLIFIER
Thermocouples are the most popular temperature sensing
devices because of their low cost, interchangeability, and
ability to measure a wide range of temperatures. In
Figure 30, the EL8188 converts the differential thermocouple
voltage into single-ended signal with 10X gain. The
EL8188's rail-to-rail input characteristic allows the
thermocouple to be biased at ground and permits the
op amp to operate from a single 5V supply.
11
FN7467.6
May 29, 2009
EL8188
Small Outline Package Family (SO)
A
D
h X 45¬
(N/2)+1
N
A
PIN #1
I.D. MARK
E1
E
c
SEE DETAIL “
1
(N/2)
B
L1
0.010 M C A B
e
H
C
A2
GAUGE
PLANE
SEATING
PLANE
A1
0.004 C
0.010 M C A B
L
b
0.010
4¬× ¬±
DETAIL X
MDP0027
SMALL OUTLINE PACKAGE FAMILY (SO)
INCHES
SYMBOL
SO-14
SO16 (0.300”)
(SOL-16)
SO20
(SOL-20)
SO24
(SOL-24)
SO28
(SOL-28)
TOLERANCE
NOTES
A
0.068
0.068
0.068
0.104
0.104
0.104
0.104
MAX
-
A1
0.006
0.006
0.006
0.007
0.007
0.007
0.007
±0.003
-
A2
0.057
0.057
0.057
0.092
0.092
0.092
0.092
±0.002
-
b
0.017
0.017
0.017
0.017
0.017
0.017
0.017
±0.003
-
c
0.009
0.009
0.009
0.011
0.011
0.011
0.011
±0.001
-
D
0.193
0.341
0.390
0.406
0.504
0.606
0.704
±0.004
1, 3
E
0.236
0.236
0.236
0.406
0.406
0.406
0.406
±0.008
-
E1
0.154
0.154
0.154
0.295
0.295
0.295
0.295
±0.004
2, 3
e
0.050
0.050
0.050
0.050
0.050
0.050
0.050
Basic
-
L
0.025
0.025
0.025
0.030
0.030
0.030
0.030
±0.009
-
L1
0.041
0.041
0.041
0.056
0.056
0.056
0.056
Basic
-
h
0.013
0.013
0.013
0.020
0.020
0.020
0.020
Reference
-
16
20
24
28
Reference
-
N
SO-8
SO16
(0.150”)
8
14
16
Rev. M 2/07
NOTES:
1. Plastic or metal protrusions of 0.006” maximum per side are not included.
2. Plastic interlead protrusions of 0.010” maximum per side are not included.
3. Dimensions “D” and “E1” are measured at Datum Plane “H”.
4. Dimensioning and tolerancing per ASME Y14.5M-1994
12
FN7467.6
May 29, 2009
EL8188
SOT-23 Package Family
MDP0038
e1
D
SOT-23 PACKAGE FAMILY
A
MILLIMETERS
6
N
SYMBOL
4
E1
2
E
3
0.15 C D
1
2X
2
3
0.20 C
5
2X
e
0.20 M C A-B D
B
b
NX
0.15 C A-B
1
3
SOT23-5
SOT23-6
A
1.45
1.45
MAX
A1
0.10
0.10
±0.05
A2
1.14
1.14
±0.15
b
0.40
0.40
±0.05
c
0.14
0.14
±0.06
D
2.90
2.90
Basic
E
2.80
2.80
Basic
E1
1.60
1.60
Basic
e
0.95
0.95
Basic
e1
1.90
1.90
Basic
L
0.45
0.45
±0.10
L1
0.60
0.60
Reference
N
5
6
Reference
D
2X
TOLERANCE
Rev. F 2/07
NOTES:
C
A2
2. Plastic interlead protrusions of 0.25mm maximum per side are not
included.
SEATING
PLANE
A1
0.10 C
1. Plastic or metal protrusions of 0.25mm maximum per side are not
included.
3. This dimension is measured at Datum Plane “H”.
4. Dimensioning and tolerancing per ASME Y14.5M-1994.
NX
5. Index area - Pin #1 I.D. will be located within the indicated zone
(SOT23-6 only).
(L1)
6. SOT23-5 version has no center lead (shown as a dashed line).
H
A
GAUGE
PLANE
c
L
13
0.25
+3
0¬×-0¬
FN7467.6
May 29, 2009
EL8188
Wafer Level Chip Scale Package (WLCSP)
W3x2.6C
3x2 ARRAY 6 BALL WAFER LEVEL CHIP SCALE PACKAGE
E
D
PIN 1 ID
TOP VIEW
A2
A
A1
SYMBOL
MILLIMETERS
A
0.51 Min, 0.55 Max
A1
0.225 ±0.015
A2
0.305 ±0.013
b
Φ0.323 ±0.025
D
0.955 ±0.020
D1
0.50 BASIC
E
1.455 ±0.020
E1
1.00 BASIC
e
0.50 BASIC
SD
0.25 BASIC
SE
0.00 BASIC
Rev. 3 03/08
b
NOTES:
SIDE VIEW
1. All dimensions are in millimeters.
E1
e
SE
D1
2
SD
1
b
C
B
A
BOTTOM VIEW
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Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software 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.
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14
FN7467.6
May 29, 2009