3PEAK
1
TP1541A/ TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Features
Stable 1.3MHz GBWP Over Temperature Range
Stable 1.3MHz GBWP in VCM from 0V to VDD
0.7V/μs Slew Rate
Only 80μA of Supply Current per Amplifier
Excellent EMIRR: 80dB(1GHz)
Offset Voltage: 400uV Maximum
Offset Voltage Temperature Drift: 1uV/°C
Input Bias Current: 1pA Typical
THD+Noise: -105dB at 1kHz, -90dB at 10kHz
High CMRR/PSRR: 95dB/90dB
Beyond the Rails Input Common-Mode Range
High Output Current: 100mA
No Phase Reversal for Overdriven Inputs
Drives 2kΩ Resistive Loads
Shutdown Current: 0.2μA (TP1541NA)
Single +2.1V to +6.0V Supply Voltage Range
–40°C to 125°C Operation Temperature Range
ESD Rating:
Robust 8KV – HBM, 2KV – CDM and 500V – MM
Green, Popular Type Package
Applications
Audio Output
Active Filters, ASIC Input or Output Amplifier
Portable Instruments and Mobile Equipment
Battery or Solar Powered Systems
Smoke/Gas/Environment Sensors
Piezo Electrical Transducer Amplifier
Medical Equipment
PCMCIA Cards
Description
TP154xA series are CMOS single/dual/quad
op-amps with low offset, stable high frequency
response, low power, low supply voltage, and
rail-to-rail inputs and outputs. They incorporate
3PEAK‟s proprietary and patented design
techniques to achieve best in-class performance
among all micro-power CMOS amplifiers in its
power class. The TP154xA family can be used as
plug-in replacements for many commercially
available op-amps to reduce power and improve
input/output range and performance.
TP154xA are unity gain stable with Any Capacitive
load with a constant 1.3MHz GBWP, 0.7V/μs slew
rate while consuming only 80μA of quiescent current
per amplifier. Analog trim and calibration routine
reduce input offset voltage to below 0.4mV, and
proprietary precision temperature compensation
technique makes offset voltage temperature drift at
1μV/°C. Adaptive biasing and dynamic
compensation enables the TP154xA to achieve
„THD+Noise‟ for 1kHz/10kHz 2VPP signal at -105dB
and -90dB, respectively. Beyond the rails input and
rail-to-rail output characteristics allow the full
power-supply voltage to be used for signal range.
This combination of features makes the TP154xA
ideal choices for battery-powered applications
because they minimize errors due to power supply
voltage variations over the lifetime of the battery and
maintain high CMRR even for a rail-to-rail input
op-amp. General audio output, remote battery-
powered sensors, and smoke detector can benefit
from the features of the TP154xA op-amps.
For applications that require power-down, the
TP1541NA in popular type packages has a
low-power shutdown mode that reduces supply current
to 0.2μA, and forces the output into a high-impedance
state.
3PEAK and the 3PEAK logo are registered trademarks of
3PEAK INCORPORATED. All other trademarks are the property
of their respective owners.
Pin Configuration
(Top View)
TP1541A
5-Pin SOT23/SC70
(-T and -C Suffixes)
4
5
3
2
1
Out
+In -In
﹣Vs
﹢Vs
TP1542A
8-Pin SOIC/TSSOP/MSOP
(-S, -T and -V Suffixes)
8
6
5
7
3
2
1
4
Out A
﹢In A
﹣In A
﹢In B
﹣In B
Out B
A
B
﹣Vs
﹢Vs
TP1544A
14-Pin SOIC/TSSOP
(-S and -T Suffixes)
14
13
12
11
10
9
8
6
5
7
3
2
1
4
Out A
﹢In A
﹣In A
DA
CB
Out D
﹢In D
﹣In D
Out B
﹢In B
﹣In B
Out C
﹢In C
﹣In C
﹣Vs
﹢Vs
5
TP1541NA
6-Pin SC70
(-C Suffix)
4
6
3
2
1
+In
-VS
-In Out
+VS
SHDN
8
7
6
54
3
2
1
Out A
﹢In A
﹣In A
﹣Vs ﹢In B
﹣In B
Out B
﹢Vs
TP1542A
8-Pin DFN
(-F Suffix)
2
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Absolute Maximum Ratings
Note 1
Supply Voltage: V+ – V–....................................7.0V
Input Voltage............................. V– – 0.3 to V+ + 0.3
Input Current: +IN, –IN, SHDN Note 2.............. ±10mA
Differential Input Voltage................................ ±7V
SHDN Pin Voltage……………………………V– to V+
Output Short-Circuit Duration Note 3…............ Infinite
Operating Temperature Range.......–40°C to 125°C
Maximum Junction Temperature................... 150°C
Storage Temperature Range.......... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) ......... 260°C
Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any
Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime.
Note 2: The inputs are protected by ESD protection diodes to each power supply. If the input extends more than 500mV beyond the power
supply, the input current should be limited to less than 10mA.
Note 3: A heat sink may be required to keep the junction temperature below the absolute maximum. This depends on the power supply
voltage and how many amplifiers are shorted. Thermal resistance varies with the amount of PC board metal connected to the package. The
specified values are for short traces connected to the leads.
ESD, Electrostatic Discharge Protection
Parameter
Condition
Minimum Level
Unit
Human Body Model ESD
MIL-STD-883H Method 3015.8
8
kV
Machine Model ESD
JEDEC-EIA/JESD22-A115
500
V
Charged Device Model ESD
JEDEC-EIA/JESD22-C101E
2
kV
Order Information
Model Name
Order Number
Package
Transport Media, Quantity
Marking
Information
TP1541A
TP1541A-TR
5-Pin SOT23
Tape and Reel, 3000
541
TP1541NA
TP1541NA-CR
6-Pin SC70
Tape and Reel, 3000
54N
TP1542A
TP1542A-SR
8-Pin SOIC
Tape and Reel, 4000
1542A
TP1542A-VR
8-Pin MSOP
Tape and Reel, 3000
1542A
TP1542A-FR
8-Pin DFN
Tape and Reel, 3000
542
TP1544A
TP1544A-SR
14-Pin SOIC
Tape and Reel, 2500
1544A
TP1544A-TR
14-Pin TSSOP
Tape and Reel, 3000
1544A
3
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Electrical Characteristics
The specifications are at TA = 27° C. VS = 5V, VCM = 2.5V, RL = 2kΩ, CL =100pF, Unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VOS
Input Offset Voltage
VCM = 0V to 3V
-400
±50
+400
μV
VOS TC
Input Offset Voltage Drift
-40°C to 125°C
1
μV/° C
IB
Input Bias Current
TA = 27 °C
1
10
pA
TA = 85 °C
25
pA
IOS
Input Offset Current
0.001
pA
Vn
Input Voltage Noise
f = 0.1Hz to 10Hz
7
μVPP
en
Input Voltage Noise Density
f = 1kHz
27
nV/√Hz
in
Input Current Noise
f = 1kHz
2
fA/√Hz
CIN
Input Capacitance
Differential
Common Mode
7.76
6.87
pF
CMRR
Common Mode Rejection Ratio
VCM = 0.1V to 2.6V
85
95
dB
VCM
Common-mode Input Voltage
Range
V– -0.3
V++0.3
V
PSRR
Power Supply Rejection Ratio
VCM = 2.5V, VS = 3V to 5V
77
90
dB
AVOL
Open-Loop Large Signal Gain
RLOAD = 10kΩ
98
120
dB
VOL, VOH
Output Swing from Supply Rail
RLOAD = 10kΩ
3
6
mV
ROUT
Closed-Loop Output Impedance
G = 1, f =1kHz, IOUT = 0
0.002
Ω
RO
Open-Loop Output Impedance
f = 1kHz, IOUT = 0
125
Ω
ISC
Output Short-Circuit Current
Sink or source current
90
100
mA
IO
Output Current
Sink or source current, Output 1V Drop
50
mA
VDD
Supply Voltage
2.1
6.0
V
IQ
Quiescent Current per Amplifier
VS = 5V
80
110
μA
PM
Phase Margin
RLOAD = 1kΩ, CLOAD = 60pF
65
°
GM
Gain Margin
RLOAD = 1kΩ, CLOAD = 60pF
15
dB
GBWP
Gain-Bandwidth Product
f = 1kHz
1.3
MHz
SR
Slew Rate
AV = 1, VOUT = 1.5V to 3.5V, CLOAD = 60pF,
RLOAD = 1kΩ
0.7
V/μs
tS
Settling Time, 0.1%
Settling Time, 0.01%
AV = –1, VOUT = 1V Step
3.7
4.9
μs
THD+N
Total Harmonic Distortion and
Noise
f = 1kHz, AV =1, RL = 2kΩ, VOUT = 1Vp-p
-105
dB
Xtalk
Channel Separation
f = 1kHz, RL = 2kΩ
110
dB
IQ(OFF)
Supply Current in Shutdown
VS = 5V
0.2
μA
ISHDN
Shutdown Pin Current
VSHDN = 0.5V
-0.15
μA
VSHDN = 1.5V
-0.15
μA
ILEAK
Output Leakage Current in
Shutdown
VSHDN = 0V, VOUT = 0V
-20
pA
VSHDN = 0V, VOUT = 5V
20
pA
VIL
SHDN Input Low Voltage
Disable
0.5
V
VIH
SHDN Input High Voltage
Enable
1.0
V
tON
Turn-On Time
SHDN Toggle from 0V to 5V
20
ms
tOFF
Turn-Off Time
SHDN Toggle from 5V to 0V
20
ms
4
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Typical Performance Characteristics
VS = ±2.75V, VCM = 0V, RL = Open, unless otherwise specified.
Offset Voltage Production Distribution Unity Gain Bandwidth vs. Temperature
Open-Loop Gain and Phase Input Voltage Noise Spectral Density
Input Bias Current vs. Temperature Input Bias Current vs. Input Common Mode Voltage
0
500
1000
1500
2000
2500
3000
-400
-350
-300
-250
-200
-150
-100
-50
0
50
100
150
200
250
300
350
400
Population
Offset Voltage(μV)
Number =46247pcs
0.0
0.3
0.5
0.8
1.0
1.3
1.5
1.8
2.0
-50 0 50 100 150
GBW(MHz)
Temperature(℃)
-150
-100
-50
0
50
100
150
200
-60
-40
-20
0
20
40
60
80
100
120
140
0.1 10 1k 100k 10M 1000M
Phase (°)
Gain(dB)
Frequency (Hz)
Phase
Gain
1
10
100
1000
110 100 1k 10k 100k 1M
Noise(nV/√Hz)
Frequency(Hz)
-10
0
10
20
30
40
50
-40 -20 0 20 40 60 80 100 120
Input Bias Current(pA)
Temperature(℃)
-25
-20
-15
-10
-5
0
0 1 2 3 4 5
Input Bias Current(pA)
Common Mode Voltage(V)
5
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Typical Performance Characteristics
VS = ±2.75V, VCM = 0V, RL = Open, unless otherwise specified. (Continued)
Common Mode Rejection Ratio CMRR vs. Frequency
Quiescent Current vs. Temperature Short Circuit Current vs. Temperature
Power-Supply Rejection Ratio Quiescent Current vs. Supply Voltage
0
20
40
60
80
100
120
140
0 1 2 3 4 5
CMRR(dB)
Common-mode Voltage(V)
0
20
40
60
80
100
120
140
160
110 100 1k 10k 100k 1M
CMRR(dB)
Frequency(Hz)
0
20
40
60
80
100
120
-50 0 50 100 150
Supply current(μA)
Temperature(℃)
VCM= 0V
VCM= 2.5V
VCM= 5.0V
0
20
40
60
80
100
120
140
-50 0 50 100 150
Current(mA)
Temperature(℃)
ISINK
ISOURCE
-20
0
20
40
60
80
100
120
0.1 10 1k 100k
PSRR(dB)
Frequency(Hz)
PSRR+
PSRR-
0
20
40
60
80
100
120
1.5 2 2.5 3 3.5 4 4.5 5
Supply current (uA)
Supply Voltage (V)
6
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Typical Performance Characteristics
VS = ±2.75V, VCM = 0V, RL = Open, unless otherwise specified. (Continued)
PSRR vs. Temperature CMRR vs. Temperature
EMIRR IN+ vs. Frequency Large-Scale Step Response
Negative Over-Voltage Recovery Positive Over-Voltage Recovery
0
20
40
60
80
100
120
-50 0 50 100 150
PSRR(-dB)
Temperature(℃)
0
20
40
60
80
100
120
140
-50 0 50 100 150
CMRR(-dB)
Temperature(℃)
0
10
20
30
40
50
60
70
80
90
110 100 1000
EMIRR IN+ (dB)
Frequency (MHz)
Time (50μs/div)
2V/div 2V/div
Gain = 1
RL= 10kΩ
Time (50μs/div)
1V/div 2V/div
Gain = +10
±V = ±2.5V
Time (50μs/div)
1V/div 2V/div
Gain = +10
±V = ±2.5V
7
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Typical Performance Characteristics
VS = ±2.75V, VCM = 0V, RL = Open, unless otherwise specified. (Continued)
0.1 Hz TO 10 Hz Input Voltage Noise Offset Voltage vs Common-Mode Voltage
Positive Output Swing vs. Load Current Negative Output Swing vs. Load Current
Offset Voltage vs. Temperature
Time (1s/div)
5μV/div
-900
-800
-700
-600
-500
-400
-300
-200
-100
0
100
200
0 1 2 3 4 5
Offset voltage(μV)
Common-mode voltage(V)
0
20
40
60
80
100
120
0 1 2 3 4 5
Iout(mA)
Vout Dropout (V)
25℃
-40℃
125℃
-140
-120
-100
-80
-60
-40
-20
0
012345
Iout(mA)
Vout Dropout (V)
25℃
-40℃
125℃
0
10
20
30
40
50
60
70
80
-50 0 50 100 150
Offset voltage(μV)
Temperature(℃)
8
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Pin Functions
–IN: Inverting Input of the Amplifier. Voltage range
of this pin can go from V– – 0.3V to V+ + 0.3V.
+IN: Non-Inverting Input of Amplifier. This pin has
the same voltage range as –IN.
+VS: Positive Power Supply. Typically the voltage is
from 2.1V to 6V. Split supplies are possible as long
as the voltage between V+ and V– is between 2.1V
and 6V. A bypass capacitor of 0.1μF as close to the
part as possible should be used between power
supply pins or between supply pins and ground.
-VS: Negative Power Supply. It is normally tied to
ground. It can also be tied to a voltage other than
ground as long as the voltage between V+ and V– is
from 2.1V to 6V. If it is not connected to ground,
bypass it with a capacitor of 0.1μF as close to the
part as possible.
SHDN: Active Low Shutdown. Shutdown threshold
is 1.0V above negative supply rail. If unconnected,
the amplifier is automatically enabled.
OUT: Amplifier Output. The voltage range extends
to within millivolts of each supply rail.
N/C: No Connection.
Operation
The TP154xA family input signal range extends
beyond the negative and positive power supplies.
The output can even extend all the way to the
negative supply. The input stage is comprised of
two CMOS differential amplifiers, a PMOS stage
and NMOS stage that are active over different
ranges of common mode input voltage. The
Class-AB control buffer and output bias stage uses
a proprietary compensation technique to take full
advantage of the process technology to drive very
high capacitive loads. This is evident from the
transient over shoot measurement plots in the
Typical Performance Characteristics.
Applications Information
Low Supply Voltage and Low Power Consumption
The TP154xA family of operational amplifiers can operate with power supply voltages from 2.1V to 6.0V. Each
amplifier draws only 80μA quiescent current. The low supply voltage capability and low supply current are ideal
for portable applications demanding HIGH CAPACITIVE LOAD DRIVING CAPABILITY and CONSTANT WIDE
BANDWIDTH. The TP154xA family is optimized for wide bandwidth low power applications. They have an
industry leading high GBWP to power ratio and are unity gain stable for ANY CAPACITIVE load. When the load
capacitance increases, the increased capacitance at the output pushed the non-dominant pole to lower frequency
in the open loop frequency response, lowering the phase and gain margin. Higher gain configurations tend to
have better capacitive drive capability than lower gain configurations due to lower closed loop bandwidth and
hence higher phase margin.
Low Input Referred Noise
The TP154xA family provides a low input referred noise density of 27nV/√Hz at 1kHz. The voltage noise will
grow slowly with the frequency in wideband range, and the input voltage noise is typically 7μVP-P at the frequency
of 0.1Hz to 10Hz.
Low Input Offset Voltage
The TP154xA family has a low offset voltage of 400μV maximum which is essential for precision applications. The
offset voltage is trimmed with a proprietary trim algorithm to ensure low offset voltage for precision signal
processing requirement.
9
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Low Input Bias Current
The TP154xA family is a CMOS OPA family and features very low input bias current in pA range. The low input
bias current allows the amplifiers to be used in applications with high resistance sources. Care must be taken to
minimize PCB Surface Leakage. See below section on “PCB Surface Leakage” for more details.
PCB Surface Leakage
In applications where low input bias current is critical, Printed Circuit Board (PCB) surface leakage effects need to
be considered. Surface leakage is caused by humidity, dust or other contamination on the board. Under low
humidity conditions, a typical resistance between nearby traces is 1012Ω. A 5V difference would cause 5pA of
current to flow, which is greater than the TP154xA OPA‟s input bias current at +27°C (±1pA, typical). It is
recommended to use multi-layer PCB layout and route the OPA‟s -IN and +IN signal under the PCB surface.
The effective way to reduce surface leakage is to use a guard ring around sensitive pins (or traces). The guard
ring is biased at the same voltage as the sensitive pin. An example of this type of layout is shown in Figure 1 for
Inverting Gain application.
1. For Non-Inverting Gain and Unity-Gain Buffer:
a) Connect the non-inverting pin (VIN+) to the input with a wire that does not touch the PCB surface.
b) Connect the guard ring to the inverting input pin (VIN–). This biases the guard ring to the Common Mode input voltage.
2. For Inverting Gain and Trans-impedance Gain Amplifiers (convert current to voltage, such as photo detectors):
a) Connect the guard ring to the non-inverting input pin (VIN+). This biases the guard ring to the same reference voltage as
the op-amp (e.g., VDD/2 or ground).
b) Connect the inverting pin (VIN–) to the input with a wire that does not touch the PCB surface.
VIN+ VIN- +VSGuard Ring
Figure 1
Ground Sensing and Rail to Rail Output
The TP154xA family has excellent output drive capability, delivering over 100mA of output drive current. The
output stage is a rail-to-rail topology that is capable of swinging to within 10mV of either rail. Since the inputs can
go 300mV beyond either rail, the op-amp can easily perform „true ground‟ sensing.
The maximum output current is a function of total supply voltage. As the supply voltage to the amplifier increases,
the output current capability also increases. Attention must be paid to keep the junction temperature of the IC
below 150°C when the output is in continuous short-circuit. The output of the amplifier has reverse-biased ESD
diodes connected to each supply. The output should not be forced more than 0.5V beyond either supply,
otherwise current will flow through these diodes.
ESD
The TP154xA family has reverse-biased ESD protection diodes on all inputs and output. Input and out pins can
not be biased more than 300mV beyond either supply rail.
Shut-down
The single channel OPA versions have SHDN pins that can shut down the amplifier to less than 0.2μA supply
current. The SHDN pin voltage needs to be within 0.5V of V– for the amplifier to shut down. During shutdown, the
output will be in high output resistance state, which is suitable for multiplexer applications. When left floating, the
SHDN pin is internally pulled up to the positive supply and the amplifier remains enabled.
10
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Driving Large Capacitive Load
The TP154xA family of OPA is designed to drive large capacitive loads. Refer to Typical Performance
Characteristics for “Phase Margin vs. Load Capacitance”. As always, larger load capacitance decreases overall
phase margin in a feedback system where internal frequency compensation is utilized. As the load capacitance
increases, the feedback loop‟s phase margin decreases, and the closed-loop bandwidth is reduced. This
produces gain peaking in the frequency response, with overshoot and ringing in output step response. The
unity-gain buffer (G = +1V/V) is the most sensitive to large capacitive loads.
When driving large capacitive loads with the TP154xA OPA family (e.g., > 200 pF when G = +1V/V), a small
series resistor at the output (RISO in Figure 3) improves the feedback loop‟s phase margin and stability by making
the output load resistive at higher frequencies.
Vin
Vout
Cload
Riso
Figure 3
Power Supply Layout and Bypass
The TP154xA OPA‟s power supply pin (VDD for single-supply) should have a local bypass capacitor (i.e., 0.01μF
to 0.1μF) within 2mm for good high frequency performance. It can also use a bulk capacitor (i.e., 1μF or larger)
within 100mm to provide large, slow currents. This bulk capacitor can be shared with other analog parts.
Ground layout improves performance by decreasing the amount of stray capacitance and noise at the OPA‟s
inputs and outputs. To decrease stray capacitance, minimize PC board lengths and resistor leads, and place
external components as close to the op amps‟ pins as possible.
Proper Board Layout
To ensure optimum performance at the PCB level, care must be taken in the design of the board layout. To avoid
leakage currents, the surface of the board should be kept clean and free of moisture. Coating the surface creates
a barrier to moisture accumulation and helps reduce parasitic resistance on the board.
Keeping supply traces short and properly bypassing the power supplies minimizes power supply disturbances
due to output current variation, such as when driving an ac signal into a heavy load. Bypass capacitors should be
connected as closely as possible to the device supply pins. Stray capacitances are a concern at the outputs and
the inputs of the amplifier. It is recommended that signal traces be kept at least 5mm from supply lines to minimize
coupling.
A variation in temperature across the PCB can cause a mismatch in the Seebeck voltages at solder joints and
other points where dissimilar metals are in contact, resulting in thermal voltage errors. To minimize these
thermocouple effects, orient resistors so heat sources warm both ends equally. Input signal paths should contain
matching numbers and types of components, where possible to match the number and type of thermocouple
junctions. For example, dummy components such as zero value resistors can be used to match real resistors in
the opposite input path. Matching components should be located in close proximity and should be oriented in the
same manner. Ensure leads are of equal length so that thermal conduction is in equilibrium. Keep heat sources
on the PCB as far away from amplifier input circuitry as is practical.
The use of a ground plane is highly recommended. A ground plane reduces EMI noise and also helps to maintain
a constant temperature across the circuit board.
Instrumentation Amplifier
The TP154xA OPA series is well suited for conditioning sensor signals in battery-powered applications. Figure 4
shows a two op-amp instrumentation amplifier, using the TP154xA OPA.
The circuit works well for applications requiring rejection of Common Mode noise at higher gains. The reference
voltage (VREF) is supplied by a low-impedance source. In single voltage supply applications, VREF is typically
VDD/2.
11
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Vref Vout
RG
R2 R2 R1
R1
V2
V2
11
12
2
2
=( )(1 )
OUT REF
G
RR
V V V V
RR
Figure 4
Gain-of-100 Amplifier Circuit
Figure 5 shows a Gain-of-100 amplifier circuit using two TP154xA OPAs. It draws 160uA total current from
supply rail, and has a -3dB frequency at 100kHz.
Figure 6 shows the small signal frequency response of the circuit.
Vout
Vin
90.9K 90.9K
10K 10K
-0.9V
+0.9V
Figure 5: 100kHz, 160μA Gain-of-100 Amplifier
Figure 6: Frequency response of 100kHz, 160uA Gain-of-100 Amplifier
Buffered Chemical Sensor (pH) Probe
The TP154xA OPA has input bias current in the pA range. This is ideal in buffering high impedance chemical
sensors such as pH probe. As an example, the circuit in Figure 7 eliminates expansive low-leakage cables that
that is required to connect pH probe to metering ICs such as ADC, AFE and/or MCU. A TP154xA OPA and a
lithium battery are housed in the probe assembly. A conventional low-cost coaxial cable can be used to carry
OPA‟s output signal to subsequent ICs for pH reading.
12
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
R1
10M
R2
10M
COAX
BATTERY
3V
(DURACELL
DL1620)
ALL COMPONENTS CONTAJNED WITHIN THE pH PROBE
GENERAL PURPOSE
COMBINATION
pH PROBE
(CORNING 476540)
pH
PROBE
To
ADC/AFE/MCU
Figure 7: Buffer pH Probe
Two-Pole Micro-power Sallen-Key Low-Pass Filter
Figure 8 shows a micro-power two-pole Sallen-Key Low-Pass Filter with 400Hz cut-off frequency. For best
results, the filter‟s cut-off frequency should be 8 to 10 times lower than the OPA‟s crossover frequency. Additional
OPA‟s phase margin shift can be avoided if the OPA‟s bandwidth-to-signal ratio is greater than 8. The design
equations for the 2-pole Sallen-Key low-pass filter are given below with component values selected to set a
400Hz low-pass filter cutoff frequency:
R1
1MOhm
R2
1MOhm
C1
400pF
C2
400pF
R3
2MOhm
R4
2MOhm
Vin
Vout
12
12
-3dB
3 4 3 4
R = R = R = 1M
C = C = C = 400pF
Q = Filter Peaking Factor = 1
f = 1/(2 ) = 400
R = R /(2-1/Q) ; with Q = 1, R =R
RC Hz
Figure 8
Portable Gas Sensor Amplifier
Gas sensors are used in many different industrial and medical applications. Gas sensors generate a current that
is proportional to the percentage of a particular gas concentration sensed in an air sample. This output current
flows through a load resistor and the resultant voltage drop is amplified. Depending on the sensed gas and
sensitivity of the sensor, the output current can be in the range of tens of microamperes to a few milli-amperes.
Gas sensor datasheets often specify a recommended load resistor value or a range of load resistors from which
to choose.
There are two main applications for oxygen sensors – applications which sense oxygen when it is abundantly
present (that is, in air or near an oxygen tank) and those which detect traces of oxygen in parts-per-million
concentration. In medical applications, oxygen sensors are used when air quality or oxygen delivered to a patient
needs to be monitored. In fresh air, the concentration of oxygen is 20.9% and air samples containing less than 18%
oxygen are considered dangerous. In industrial applications, oxygen sensors are used to detect the absence of
oxygen; for example, vacuum-packaging of food products.
The circuit in Figure 9 illustrates a typical implementation used to amplify the output of an oxygen detector. With
the components shown in the figure, the circuit consumes less than 37μA of supply current ensuring that small
form-factor single- or button-cell batteries (exhibiting low mAh charge ratings) could last beyond the operating life
of the oxygen sensor. The precision specifications of these amplifiers, such as their low offset voltage, low TC-VOS,
13
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
low input bias current, high CMRR, and high PSRR are other factors which make these amplifiers excellent
choices for this application.
100KOhm
1%
100Ohm
1%
Vout
100KOhm
1%
10MOhm
1%
2
O
I
2
1 in Air ( 21% O )
0.7
OUT
DD
VV
I uA
Oxygen Sensor
City Technology
4OX2
Figure 9
14
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Package Outline Dimensions
SC70-5(SC70-6)
SOT23-5(SOT23-6)
Symbol
Dimensions
In Millimeters
Dimensions
In Inches
Min
Max
Min
Max
A
1.050
1.250
0.041
0.049
A1
0.000
0.100
0.000
0.004
A2
1.050
1.150
0.041
0.045
b
0.300
0.400
0.012
0.016
C
0.100
0.200
0.004
0.008
D
2.820
3.020
0.111
0.119
E
1.500
1.700
0.059
0.067
E1
2.650
2.950
0.104
0.116
e
0.950TYP
0.037TYP
e1
1.800
2.000
0.071
0.079
L
0.700REF
0.028REF
L1
0.300
0.460
0.012
0.024
θ
0°
8°
0°
8°
Symbol
Dimensions
In Millimeters
Dimensions
In Inches
Min
Max
Min
Max
A
0.900
1.100
0.035
0.043
A1
0.000
0.100
0.000
0.004
A2
0.900
1.000
0.035
0.039
b
0.150
0.350
0.006
0.014
C
0.080
0.150
0.003
0.006
D
2.000
2.200
0.079
0.087
E
1.150
1.350
0.045
0.053
E1
2.150
2.450
0.085
0.096
e
0.650TYP
0.026TYP
e1
1.200
1.400
0.047
0.055
L
0.525REF
0.021REF
L1
0.260
0.460
0.010
0.018
θ
0°
8°
0°
8°
15
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Package Outline Dimensions
SOIC-8
MSOP-8
Symbol
Dimensions
In Millimeters
Dimensions In
Inches
Min
Max
Min
Max
A
1.350
1.750
0.053
0.069
A1
0.100
0.250
0.004
0.010
A2
1.350
1.550
0.053
0.061
B
0.330
0.510
0.013
0.020
C
0.190
0.250
0.007
0.010
D
4.780
5.000
0.188
0.197
E
3.800
4.000
0.150
0.157
E1
5.800
6.300
0.228
0.248
e
1.270TYP
0.050TYP
L1
0.400
1.270
0.016
0.050
θ
0°
8°
0°
8°
Symbol
Dimensions
In Millimeters
Dimensions In
Inches
Min
Max
Min
Max
A
0.800
1.200
0.031
0.047
A1
0.000
0.200
0.000
0.008
A2
0.760
0.970
0.030
0.038
b
0.30 TYP
0.012 TYP
C
0.15 TYP
0.006 TYP
D
2.900
3.100
0.114
0.122
e
0.65 TYP
0.026
E
2.900
3.100
0.114
0.122
E1
4.700
5.100
0.185
0.201
L1
0.410
0.650
0.016
0.026
θ
0°
6°
0°
6°
16
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Package Outline Dimensions
DFN-8
Symbol
Dimensions
In Millimeters
Dimensions In Inches
Min
Nom
Max
Min
Nom
Max
A
0.80
0.85
0.9
0.031
0.033
0.035
A1
0.00
0.02
0.05
0.000
0.001
0.002
A2
0.153
0.203
0.253
0.006
0.008
0.010
b
0.18
0.24
0.30
0.007
0.009
0.012
D
1.9
2.0
2.1
0.075
0.079
0.083
E
1.9
2.0
2.1
0.075
0.079
0.083
D1
0.5
0.6
0.7
0.020
0.024
0.028
E1
1.1
1.2
1.3
0.043
0.047
0.051
e
0.50
0.20
k
0.2
0.008
L
0.25
0.35
0.45
0.010
0.014
0.018
17
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
www.3peakic.com.cn Rev. B.04
Package Outline Dimensions
SOIC-14
Symbol
Dimensions
In Millimeters
MIN
NOM
MAX
A
1.35
1.60
1.75
A1
0.10
0.15
0.25
A2
1.25
1.45
1.65
A3
0.55
0.65
0.75
b
0.36
0.49
b1
0.35
0.40
0.45
c
0.16
0.25
c1
0.15
0.20
0.25
D
8.53
8.63
8.73
E
5.80
6.00
6.20
E1
3.80
3.90
4.00
e
1.27 BSC
L
0.45
0.60
0.80
L1
1.04 REF
L2
0.25 BSC
R
0.07
R1
0.07
h
0.30
0.40
0.50
θ
0°
8°
θ1
6°
8°
10°
θ2
6°
8°
10°
θ3
5°
7°
9°
θ4
5°
7°
9°
18
TP1541A/TP1541NA/TP1542A/TP1544A
Stable 1.3MHz, Precision, RRIO, Op Amps
Rev. B.04 www.3peakic.com.cn
Package Outline Dimensions
TSSOP-14
Symbol
Dimensions
In Millimeters
MIN
NOM
MAX
A
-
-
1.20
A1
0.05
-
0.15
A2
0.90
1.00
1.05
A3
0.34
0.44
0.54
b
0.20
-
0.28
b1
0.20
0.22
0.24
c
0.10
-
0.19
c1
0.10
0.13
0.15
D
4.86
4.96
5.06
E
6.20
6.40
6.60
E1
4.30
4.40
4.50
e
0.65 BSC
L
0.45
0.60
0.75
L1
1.00 REF
L2
0.25 BSC
R
0.09
-
-
R1
0.09
-
-
s
0.20
-
θ1
0°
-
8°
θ2
10°
12°
14°
θ3
10°
12°
14°