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LTC728XT14/R6

LTC728XT14/R6

  • 厂商:

    LINEARIN(先积)

  • 封装:

    TSSOP14L

  • 描述:

    四路,精密,11MHz,低功耗,低噪声,RRIO,CMOS放大器

  • 数据手册
  • 价格&库存
LTC728XT14/R6 数据手册
LTC725, LTC726, LTC727, LTC728 P-1 General Description The LTC72x family of single-, dual-, and quad- channel operational amplifiers represents a new generation of general-purpose, low-power op-amps. Featuring railto-rail input and output (RRIO) swings, low quiescent current (typical 750 µA) combined with a wide bandwidth (11 MHz) and very low noise (8 nV/√Hz at 10 kHz) makes this family very attractive for a variety of battery-powered applications that require a good balance between cost and performance, such as audio outputs, motor phase current sensing, photodiode amplification, barcode scanners and white goods. The low input bias current supports these amplifiers to be used in applications with mega-ohm source impedances. The robust design of the LTC72x amplifiers provides ease-of-use to the circuit designer: unity-gain stability with capacitive loads of up to 300 pF, integrated RF/EMI rejection filter, no phase reversal in overdrive conditions, and high electro-static discharge (ESD) protection (5-kV HBM). The LTC72x amplifiers are optimized for operation at voltages as low as +1.8 V (±0.9 V) and up to +5.5 V (±2.75 V) at the temperature range of 0 ℃ to 70 ℃, and operation at voltages from +2.0 V (±1.0 V) to +5.5 V (±2.75 V) over the extended temperature range of −40 ℃ to +125 ℃. The LTC725/LTC727 (single) is available in both SOT23-5L and SC70-5L packages. The LTC726 (dual) is offered in SOIC-8L, MSOP-8L and TSSOP-8L packages. The quadchannel LTC728 is offered in QFN-16L ,SOIC-14L and TSSOP-14L packages. Features and Benefits           Low Input Offset Voltage: ±0.35 mV Maximum Wide Unity-Gain Bandwidth: 11 MHz High Slew Rate: 11 V/μs Fast Settling: 0.26 μs to 0.1% Low Noise: 8 nV/√Hz at 10 kHz Rail-to-Rail Input and Output Internal RF/EMI Filter Single 1.8 V to 5.5 V Supply Voltage Range at 0 ℃ to 70 ℃ Low Supply Current: 750 μA at 5V Supply Per Amplifier Extended Temperature Range: −40℃ to +125℃ Applications  Battery-Powered Instruments: – Consumer, Industrial, Medical, Notebooks  Audio Outputs  Motor Phase Current Sense  Photodiode Amplification  Sensor Signal Conditioning: – Sensor Interfaces, Loop-Powered, Active Filters Pin Configurations (Top View) +IN 3 4 –IN OUTA 1 8 +VS –INA 2 7 OUTB +INA 3 6 –INB –VS 4 5 +INB SOIC-8L / MSOP-8L LTC727 SOT23-5L / SC70-5L OUTA –INA +IN 1 5 +VS –VS 2 –IN 3 1 2 +INA 3 –VS 4 8 7 A B +VS OUTB 6 –INB 5 +INB 16 15 14 13 +INA 1 12 +IND +VS 2 11 –VS +INB 3 10 +INC –INB 4 9 5 6 7 8 OUTC 2 +VS NC –VS 5 NC 1 OUTB OUT –IND LTC728 SOIC-14L / TSSOP-14L OUTD LTC728 QFN3x3-16L OUTA LTC726 DFN2x2-8L –INA LTC725 SOT23-5L / SC70-5L 4 OUT CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. –INC OUTA 1 14 OUTD –INA 2 13 –IND +INA 3 12 +IND +VS 4 11 –VS +INB 5 10 +INC –INB 6 9 –INC OUTB 7 8 OUTC A B D C FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-2 Pin Description Symbol Description –IN Inverting input of the amplifier. The voltage range is from (VS– – 0.1V) to (VS+ + 0.1V). +IN Non-inverting input of the amplifier. This pin has the same voltage range as –IN. +VS Positive power supply. –VS Negative power supply. OUT Amplifier output. Ordering Information Type Number Package Name Package Quantity Marking Code (1) LTC725XT5/R6 SOT23-5L Tape and Reel, 3 000 AH1I LTC725XC5/R6 SC70-5L Tape and Reel, 3 000 H5 LTC727XT5/R6 SOT23-5L Tape and Reel, 3 000 AH3I LTC727XC5/R6 SC70-5L Tape and Reel, 3 000 H7 LTC726XF8/R6 DFN2x2-8L Tape and Reel, 3 000 AH2T LTC726XS8/R8 SOIC-8L Tape and Reel, 4 000 AH2IX LTC726XV8/R6 MSOP-8L Tape and Reel, 3 000 AH2T LTC726XT8/R6 TSSOP-8L Tape and Reel, 3 000 AH2T LTC728XS14/R5 SOIC-14L Tape and Reel, 2 500 AH4IX LTC728XF16/R6 QFN3x3-16L Tape and Reel, 3 000 AH4T LTC728XT14/R6 TSSOP-14L Tape and Reel, 3 000 AH4IX (1) There may be multiple device markings, a varied marking character of “x” , or additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-3 Limiting Value -In accordance with the Absolute Maximum Rating System (IEC 60134). Parameter Absolute Maximum Rating Supply Voltage, VS+ to VS– 10.0 V Signal Input Terminals: Voltage, Current VS– – 0.5 V to VS+ + 0.5 V, ±10 mA Output Short-Circuit Continuous Storage Temperature Range, Tstg –65 ℃ to +150 ℃ Junction Temperature, TJ 150 ℃ Lead Temperature Range (Soldering 10 sec) 260 ℃ ESD Rating Parameter Electrostatic Discharge Voltage Item Value Human body model (HBM), per MIL-STD-883J / Method 3015.9 (1) ±5 000 Charged device model (CDM), per ESDA/JEDEC JS-002-2014 (2) ±2 000 Machine model (MM), per JESD22-A115C ±250 Unit V (1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 500-V HBM is possible if necessary precautions are taken. (2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 250-V CDM is possible if necessary precautions are taken. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-4 Electrical Characteristics VS = 5.0V, TA = +25℃, VCM = VS /2, VO = VS /2, and RL = 10kΩ connected to VS /2, unless otherwise noted. Boldface limits apply over the specified temperature range, TA = −40 to +125 ℃. Symbol Parameter Conditions Min. Typ. Max. LTC725, LTC726, LTC727 ±0.10 ±0.35 LTC728 ±0.12 ±0.50 ±1 2.3 Unit OFFSET VOLTAGE VOS Input offset voltage VOS TC Offset voltage drift TA = −40 to +125 ℃ PSRR Power supply rejection ratio VS = 2.0 to 5.5 V, VCM < VS+ − 2V 95 TA = −40 to +125 ℃ 82 110 mV μV/℃ dB INPUT BIAS CURRENT 1 IB IOS Input bias current TA = +85 ℃ 150 TA = +125 ℃ 500 Input offset current pA 1 pA μVP-P NOISE Vn Input voltage noise f = 0.1 to 10 Hz 3 en Input voltage noise density f = 100 Hz 19 f = 10 kHz 8 In Input current noise density f = 1 kHz 3 nV/√Hz fA/√Hz INPUT VOLTAGE VCM CMRR Common-mode voltage range Common-mode rejection ratio VS––0.1 VS = 5.5 V, VCM = −0.1 to 5.6 V 80 VCM = 0 to 5.3 V, TA = −40 to +125 ℃ 75 VS = 2.0 V, VCM = −0.1 to 2.1 V 76 VCM = 0 to 1.8 V, TA = −40 to +125 ℃ 70 VS++0.1 V 96 90 dB INPUT IMPEDANCE CIN Input capacitance Differential 2.0 Common mode 3.5 pF OPEN-LOOP GAIN RL = 10 kΩ, VO = 0.05 to 3.5 V AVOL Open-loop voltage gain 97 TA = −40 to +125 ℃ 87 RL = 600 Ω, VO = 0.15 to 3.5 V 85 TA = −40 to +125 ℃ 75 105 90 dB FREQUENCY RESPONSE Gain bandwidth product Slew rate G = +1, CL = 100 pF, VO = 1.5 to 3.5 V THD+N Total harmonic distortion + noise G = +1, f = 1 kHz, VO = 0.5 VRMS tS Settling time tOR Overload recovery time GBW SR 11 MHz 11 V/μs 0.0005 % To 0.1%, G = +1, 1V step 0.26 To 0.01%, G = +1, 1V step 0.34 VIN * Gain > VS 0.3 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. μs μs FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-5 Electrical Characteristics (continued) VS = 5.0V, TA = +25℃, VCM = VS /2, VO = VS /2, and RL = 10kΩ connected to VS /2, unless otherwise noted. Boldface limits apply over the specified temperature range, TA = −40 to +125 ℃. Symbol Parameter Conditions Min. Typ. Max. Unit OUTPUT VOH High output voltage swing RL = 10 kΩ VS+–12 VS+–8 RL = 600 Ω VS+–180 VS+–125 VOL Low output voltage swing RL = 10 kΩ VS–+6 VS–+9 RL = 600 Ω VS–+90 VS–+130 ISC Short-circuit current mV ±75 mV mA POWER SUPPLY VS Operating supply voltage TA = 0 to +70 ℃ 1.8 5.5 TA = −40 to +125 ℃ 2.0 5.5 IQ Quiescent current (per amplifier) VS = 2.0 V 625 760 VS = 5.0 V 750 930 V μA THERMAL CHARACTERISTICS TA θJA Operating temperature range Package Thermal Resistance –40 +125 SC70-5L 333 SOT23-5L 190 MSOP-8L 216 TSSOP-8L 160 SOIC-8L 125 QFN3x3-16L 65 TSSOP-14L 112 SOIC-14L 115 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. ℃ ℃/W FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-6 Typical Performance Characteristics At TA = +25℃, VCM = VS /2, and RL = 10kΩ connected to VS /2, unless otherwise noted. 100 -350 -300 -250 -200 -150 -100 -50 0 50 100 150 200 250 300 350 Distribution (Unit) Voltage Noise (nV/√Hz) VS = 5V VCM = –VS 4,490 Samples 500 450 400 350 300 250 200 150 100 50 0 10 1 1 100 Offset Voltage (μV) 1M Input Voltage Noise Spectral Density as a function of Frequency. Offset Voltage Production Distribution 120 125 100 100 PSRR (dB) 80 CMRR (dB) 10k Frequency (Hz) 60 40 75 50 25 20 0 0 1 100 10k 1M 1 100 Frequency (Hz) 10k 1M Frequency (Hz) Common-mode Rejection Ratio as a function of Frequency. Power Supply Rejection Ratio as a function of Frequency. 120 160 1000 90 120 60 80 30 40 0 0 -30 -40 10 1k 100k 10M Quiescent Current (μA) Phase (deg) AOL (dB) 900 800 700 600 500 400 300 200 100 0 1.5 Open-loop Gain and Phase as a function of Frequency. 2 2.5 3 3.5 4 4.5 5 5.5 Supply Voltage (V) Frequency (Hz) Quiescent Current as a function of Supply Voltage. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-7 Typical Performance Characteristics (continued) At TA = +25℃, VCM = VS /2, and RL = 10kΩ connected to VS /2, unless otherwise noted. 875 VS = 5V 1,000 Quiescent Current (µA) Quiescent Current (μA) 1,250 750 500 250 0 VS = 5V 750 625 500 375 250 125 0 -50 -25 0 25 50 75 100 125 0 1 Temperature (℃) 3 4 Quiescent Current as a function of Input Commonmode Voltage. 5 4 –40℃ 3 +125℃ 2 +25℃ 1 Sinking Current 0 0 20 40 60 80 (mA) Current(mA) Short-circuit Short-circuitCurrent 100 Sourcing Current 80 – ISC 60 40 +ISC 20 0 100 1.5 2 Output Current (mA) 2.5 3 3.5 4 4.5 Short-circuit Current as a function of Supply Voltage. 125 VS = 5V 100 1 V/div 75 50 CL = 100pF AV = +1 25 0 -50 -25 0 25 50 75 5 Supply SupplyVoltage Voltage(V) (V) Output Voltage Swing as a function of Output Current. Short-circuit Current (mA) 5 Common-Mode Voltage (V) Quiescent Current as a function of Temperature. Output Voltage (V) 2 100 125 Temperature (℃) Short-circuit Current as a function of Temperature. 0.25 µs/div Large Signal Step Response. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. 5.5 FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-8 Typical Performance Characteristics (continued) CL = 100pF AV = +1 25 mV/div 100 mV/div At TA = +25℃, VCM = VS /2, and RL = 10kΩ connected to VS /2, unless otherwise noted. CL = 100pF AV = +1 100 ns/div Small Signal Step Response (500 mV). 100 ns/div Small Signal Step Response (500 mV). CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers P-9 LTC725, LTC726, LTC727, LTC728 Application Notes The LTC72x is a family of low-power, rail-to-rail input and output operational amplifiers specifically designed for portable applications. These devices operate from 1.8 V to 5.5 V at the temperature range of 0 ℃ to 70 ℃, are unity-gain stable, and suitable for a wide range of general-purpose applications. The class AB output stage is capable of driving ≤ 10kΩ loads connected to any point between VS+ and ground. The input common-mode voltage range includes both rails, and allows the LTC72x family to be used in virtually any single-supply application. Rail-to-rail input and output swing significantly increases dynamic range, especially in low-supply applications, and makes them ideal for driving sampling analog-to-digital converters (ADCs). The LTC72x features 11-MHz bandwidth and 11 -V/μs slew rate with only 750-μA supply current per amplifier, providing good ac performance at very low power consumption. DC applications are also well served with a low input noise voltage of 8-nV/√Hz at 1-kHz, low input bias current, and an input offset voltage of 0.35-mV maximum. The typical offset voltage drift is 1-μV/℃, over the full temperature range the input offset voltage changes only 100-μV (0.35-mV to 0.45-mV). OPERATING VOLTAGE The LTC72x family is optimized for operation at voltages as low as +1.8 V (±0.9 V) and up to +5.5 V (±2.75 V) at the temperature range of 0 ℃ to 70 ℃, and fully specified and ensured for operation from 2.0 V to 5.5 V (±1.0 V to ±2.75 V). In addition, many specifications apply from –40 ℃ to +125 ℃. Parameters that vary significantly with operating voltages or temperature are illustrated in the Typical Characteristics graphs. NOTE: Supply voltages (VS+ to VS–) higher than +10 V can permanently damage the device. RAIL-TO-RAIL INPUT The input common-mode voltage range of the LTC72x series extends 100-mV beyond the negative and positive supply rails. This performance is achieved with a complementary input stage: an N-channel input differential pair in parallel with a P-channel differential pair. The N-channel pair is active for input voltages close to the positive rail, typically VS+– 1.4 V to the positive supply, whereas the P-channel pair is active for inputs from 100-mV below the negative supply to approximately VS+–1.4 V. There is a small transition region, typically VS+–1.2 V to VS+–1 V, in which both pairs are on. This 200-mV transition region can vary up to 200-mV with process variation. Thus, the transition region (both stages on) can range from VS+–1.4 V to VS+–1.2 V on the low end, up to VS+–1 V to VS+–0.8 V on the high end. Within this transition region, PSRR, CMRR, offset voltage, offset drift, and THD can be degraded compared to device operation outside this region. The typical input bias current of the LTC72x during normal operation is approximately 1-pA. In overdriven conditions, the bias current can increase significantly. The most common cause of an overdriven condition occurs when the operational amplifier is outside of the linear range of operation. When the output of the operational amplifier is driven to one of the supply rails, the feedback loop requirements cannot be satisfied and a differential input voltage develops across the input pins. This differential input voltage results in activation of parasitic diodes inside the front-end input chopping switches that combine with electromagnetic interference (EMI) filter resistors to create the equivalent circuit. Notice that the input bias current remains within specification in the linear region. INPUT EMI FILTER AND CLAMP CIRCUIT Figure 1 shows the input EMI filter and clamp circuit. The LTC72x op-amps have internal ESD protection diodes (D1, D2, D3, and D4) that are connected between the inputs and each supply rail. These diodes protect the input transistors in the event of electrostatic discharge and are reverse biased during normal operation. This protection scheme allows voltages as high as approximately 500-mV beyond the rails to be applied at the input of either terminal without causing permanent damage. These ESD protection current-steering diodes also provide in-circuit, input overdrive protection, as long as the current is limited to 20-mA as stated in the Absolute Maximum Ratings. VS+ D1 RS1 5kΩ IN+ D2 D3 CCM1 RS2 CDM 5kΩ IN– D4 CCM2 VS– Figure 1. Input EMI Filter and Clamp Circuit Operational amplifiers vary in susceptibility to EMI. If conducted EMI enters the operational amplifier, the dc offset at the amplifier output can shift from its nominal value when EMI is present. This shift is a result of signal rectification associated with the internal semiconductor junctions. Although all operational amplifier pin functions can be affected by EMI, the input pins are likely to be the most susceptible. The EMI filter of the LTC72x family is CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-10 Application Notes (continued) composed of two 5-kΩ input series resistors (RS1 and RS2), two common-mode capacitors (CCM1 and CCM2), and a differential capacitor (CDM). These RC networks set the −3 dB low-pass cutoff frequencies at 35-MHz for common-mode signals, and at 22-MHz for differential signals. RAIL-TO-RAIL OUTPUT Designed as a micro-power, low-noise operational amplifier, the LTC72x delivers a robust output drive capability. A class AB output stage with commonsource transistors is used to achieve full rail-to-rail output swing capability. For resistive loads up to 100kΩ, the output swings typically to within 5-mV of either supply rail regardless of the power-supply voltage applied. Different load conditions change the ability of the amplifier to swing close to the rails. For resistive loads up to 600-Ω, the output swings typically to within 125-mV of the positive supply rail and within 90-mV of the negative supply rail. signal with the output. The CF and RISO serve to counteract the loss of phase margin by feeding the high frequency component of the output signal back to the amplifier’s inverting input, thereby preserving phase margin in the overall feedback loop. For no-buffer configuration, there are two others ways to increase the phase margin: (a) by increasing the amplifier’s gain, or (b) by placing a capacitor in parallel with the feedback resistor to counteract the parasitic capacitance associated with inverting node. CF VIN CL The LTC72x family can safely drive capacitive loads of up to 300-pF in any configuration. As with most amplifiers, driving larger capacitive loads than specified may cause excessive overshoot and ringing, or even oscillation. A heavy capacitive load reduces the phase margin and causes the amplifier frequency response to peak. Peaking corresponds to overshooting or ringing in the time domain. Therefore, it is recommended that external compensation be used if the LTC72x op-amps must drive a load exceeding 300-pF. This compensation is particularly important in the unity-gain configuration, which is the worst case for stability. A quick and easy way to stabilize the op-amp for capacitive load drive is by adding a series resistor, RISO, between the amplifier output terminal and the load capacitance, as shown in Figure 2. RISO isolates the amplifier output and feedback network from the capacitive load. The bigger the RISO resistor value, the more stable VOUT will be. Note that this method results in a loss of gain accuracy because RISO forms a voltage divider with the RL. RISO VOUT LTC72x CAPACITIVE LOAD AND STABILITY LTC72x RF RISO VOUT VIN CL Figure 2. Indirectly Driving Heavy Capacitive Load An improvement circuit is shown in Figure 3. It provides DC accuracy as well as AC stability. The RF provides the DC accuracy by connecting the inverting RL Figure 3. Indirectly Driving Heavy Capacitive Load with DC Accuracy OVERLOAD RECOVERY Overload recovery is defined as the time required for the operational amplifier output to recover from a saturated state to a linear state. The output devices of the operational amplifier enter a saturation region when the output voltage exceeds the rated operating voltage, either because of the high input voltage or the high gain. After the device enters the saturation region, the charge carriers in the output devices require time to return back to the linear state. After the charge carriers return back to the linear state, the device begins to slew at the specified slew rate. Thus, the propagation delay in case of an overload condition is the sum of the overload recovery time and the slew time. The overload recovery time for the LTC72x family is approximately 0.3-μs. EMI REJECTION RATIO Circuit performance is often adversely affected by high frequency EMI. When the signal strength is low and transmission lines are long, an op-amp must accurately amplify the input signals. However, all opamp pins — the non-inverting input, inverting input, positive supply, negative supply, and output pins — are susceptible to EMI signals. These high frequency signals are coupled into an op-amp by various means, such as conduction, near field radiation, or far field radiation. For example, wires and printed circuit board (PCB) traces can act as antennas and pick up high frequency EMI signals. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-11 Application Notes (continued) Amplifiers do not amplify EMI or RF signals due to their relatively low bandwidth. However, due to the nonlinearities of the input devices, op-amps can rectify these out of band signals. When these high frequency signals are rectified, they appear as a dc offset at the output. The LTC72x op-amps have integrated EMI filters at their input stage. A mathematical method of measuring EMIRR is defined as follows: EMIRR = 20 log (VIN_PEAK / ΔVOS) resulting in a thermal voltage error. This thermocouple error can be reduced by using dummy components to match the thermoelectric error source. Placing the dummy component as close as possible to its partner ensures both Seebeck voltages are equal, thus canceling the thermocouple error. Maintaining a constant ambient temperature on the circuit board further reduces this error. The use of a ground plane helps distribute heat throughout the board and reduces EMI noise pickup. INPUT-TO-OUTPUT COUPLING To minimize capacitive coupling, the input and output signal traces should not be parallel. This helps reduce unwanted positive feedback. MAXIMIZING PERFORMANCE THROUGH PROPER LAYOUT To achieve the maximum performance of the extremely high input impedance and low offset voltage of the LTC72x op-amps, care is needed in laying out the circuit board. The PCB surface must remain clean and free of moisture to avoid leakage currents between adjacent traces. Surface coating of the circuit board reduces surface moisture and provides a humidity barrier, reducing parasitic resistance on the board. The use of guard rings around the amplifier inputs further reduces leakage currents. Figure 4 shows proper guard ring configuration and the top view of a surface-mount layout. The guard ring does not need to be a specific width, but it should form a continuous loop around both inputs. By setting the guard ring voltage equal to the voltage at the non-inverting input, parasitic capacitance is minimized as well. For further reduction of leakage currents, components can be mounted to the PCB using Teflon standoff insulators. Guard Ring +IN –IN +VS Figure 4. Use a guard ring around sensitive pins Other potential sources of offset error are thermoelectric voltages on the circuit board. This voltage, also called Seebeck voltage, occurs at the junction of two dissimilar metals and is proportional to the temperature of the junction. The most common metallic junctions on a circuit board are solder-toboard trace and solder-to-component lead. If the temperature of the PCB at one end of the component is different from the temperature at the other end, the resulting Seebeck voltages are not equal, CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-12 Typical Application Circuits ACTIVE FILTER MOTOR PHASE CURRENT SENSING The LTC72x family is well-suited for active filter applications that require a wide bandwidth, fast slew rate, low-noise, single-supply operational amplifier. Figure 5 shows a 500-kHz, second-order, low-pass filter using the multiple-feedback (MFB) topology. The components have been selected to provide a maximally-flat Butterworth response. Beyond the cut-off frequency, roll-off is –40 dB/dec. The Butterworth response is ideal for applications that require predictable gain characteristics, such as the anti-aliasing filter used in front of an ADC. The current sensing amplification shown in Figure 7 has a slew rate of 2πfVPP for the output of sine wave signal, and has a slew rate of 2fVPP for the output of triangular wave signal. In most of motor control systems, the PWM frequency is at 10 kHz to 20 kHz, and one cycle time is 100 μs for a 10 kHz of PWM frequency. In current shunt monitoring for a motor phase, the phase current is converted to a phase voltage signal for ADC sampling. This sampling voltage signal must be settled before entering the ADC. As the Figure 7 shown, the total settling time of a current shunt monitor circuit includes: the rising edge delay time (tSR) due to the op-amp’s slew rate, and the measurement settling time (tSET). For a 2shunt solution of motor phase current sensing, if the minimum duty cycle of the PWM is defined at 5%, and the tSR is required at 20% of a total time window for a phase current monitoring, in case of a 3.3 V motor control system (3.3 V MCU with 12-bit ADC), the opamp’s slew rate should be more than: R3 549Ω C2 150pF VIN R1 549Ω VS+ R2 1.24kΩ VOUT LTC72x C1 1nF 3.3V / (100μs× 5% × 20%) = 3.3 V/μs At the same time, the op-amp’s bandwidth should be much greater than the PWM frequency, like 10 time at least. VS– tSR tSET Figure 5. Second-Order, Butterworth, 500-kHz LowPass Filter One point to observe when considering the MFB filter is that the output is inverted, relative to the input. If this inversion is not required, or not desired, a noninverting output can be achieved through one of these options: 1. adding an inverting amplifier; 2. adding an additional second-order MFB stage; or 3. using a non-inverting filter topology, such as the Sallen-Key (shown in Figure 6). C2 220pF VBUS tSR – Time delay due to op-amp slew rate tSET – Measurement settling time tSMP – Sampling time window High side switch To Motor Phase VM Low side switch R2 R1 C1 RSHUNT LTC72x R3 R4 VIN R1 1.8kΩ R2 19.5kΩ R3 150kΩ 1VRMS To MCU ADC pin R5 C2 VS+ Filter LTC72x C1 3.3nF tSMP Offset Amplification VOUT C3 47pF VS– Figure 6. Configured as a Three-Pole, 20-kHz, SallenKey Filter Figure 7. Current Shunt Monitor Circuit DIFFERENTIAL AMPLIFIER The circuit shown in Figure 8 performs the difference function. If the resistors ratios are equal R4/R3 = R2/R1, then: VOUT = (Vp – Vn) × R2/R1 + VREF CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-13 Typical Application Circuits (continued) low-leakage cables that that is required to connect a pH probe (general purpose combination pH probes, e.g Corning 476540) to metering ICs such as ADC, AFE and/or MCU. A LTC72x op-amp and a lithium battery are housed in the probe assembly. A conventional low-cost coaxial cable can be used to carry the op-amp’s output signal to subsequent ICs for pH reading. R2 R1 Vn LTC72x VOUT Vp R3 R4 VREF Figure 8. Differential Amplifier INSTRUMENTATION AMPLIFIER RG VREF R1 R2 R2 LTC72x R1 LTC72x VOUT V1 V2 VOUT =(V1  V2 )(1  R1 2 R1  )  VREF R2 RG Figure 9. Instrumentation Amplifier The LTC72x family is well suited for conditioning sensor signals in battery-powered applications. Figure 9 shows a two op-amp instrumentation amplifier, using the LTC72x op-amps. 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, the VREF is typically VS/2. BUFFERED CHEMICAL SENSORS Coax LTC72x R1 10MΩ 3V To ADC, AFE or MCU pH PROBE R2 10MΩ All components contained within the pH probe Figure 10. Buffered pH Probe The LTC72x family has input bias current in the pA range. This is ideal in buffering high impedance chemical sensors, such as pH probes. As an example, the circuit in Figure 10 eliminates expansive CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-14 Tape and Reel Information REEL DIMENSIONS TAPE DIMENSIONS K0 P1 B0 W Reel Diameter A0 Cavity A0 B0 K0 W P1 Reel Width (W1) Dimension designed to accommodate the component width Dimension designed to accommodate the component length Dimension designed to accommodate the component thickness Overall width of the carrier tape Pitch between successive cavity centers QUADRANT ASSIGNMENTS FOR PIN 1 ORIETATION IN TAPE Sprocket Holes Q1 Q2 Q1 Q2 Q3 Q4 Q3 Q4 User Direction of Feed Pocket Quadrants * All dimensions are nominal Device LTC725XT5/R6 Package Pins Type SOT23 5 SPQ 3 000 Reel Reel Diameter Width W1 (mm) (mm) 178 9.0 A0 (mm) B0 (mm) K0 (mm) P1 (mm) W (mm) Pin 1 Quadrant 3.3 3.2 1.5 4.0 8.0 Q3 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-15 Package Outlines DIMENSIONS, SOT23-5L A2 A A1 D e1 Symbol A A1 A2 b c D E1 E e e1 L L1 θ θ L E E1 L1 e b Dimensions In Millimeters Min Max 1.25 0.04 0.10 1.00 1.20 0.33 0.41 0.15 0.19 2.820 3.02 1.50 1.70 2.60 3.00 0.95 BSC 1.90 BSC 0.60 REF 0.30 0.60 0° 8° Dimensions In Inches Min Max 0.049 0.002 0.004 0.039 0.047 0.013 0.016 0.006 0.007 0.111 0.119 0.059 0.067 0.102 0.118 0.037 BSC 0.075 BSC 0.024 REF 0.012 0.024 0° 8° c RECOMMENDED SOLDERING FOOTPRINT, SOT23-5L 1.0 0.039 0.95 0.037 0.95 0.037 0.7 0.028 2.4 0.094 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. mm ( inches ) FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-16 Package Outlines (continued) DIMENSIONS, SC70-5L (SOT353) A2 A Symbol A1 D e1 A A1 A2 b C D E E1 e e1 L L1 θ θ e L E1 E L1 b Dimensions In Millimeters Min Max 0.90 1.10 0.00 0.10 0.90 1.00 0.15 0.35 0.08 0.15 2.00 2.20 1.15 1.35 2.15 2.45 0.65 typ. 1.20 1.40 0.525 ref. 0.26 0.46 0° 8° C RECOMMENDED SOLDERING FOOTPRINT, SC70-5L (SOT353) 0.50 0.0197 0.65 0.0256 0.65 0.0256 0.40 0.0157 1.9 0.0748 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. mm ( inches ) Dimensions In Inches Min Max 0.035 0.043 0.000 0.004 0.035 0.039 0.006 0.014 0.003 0.006 0.079 0.087 0.045 0.053 0.085 0.096 0.026 typ. 0.047 0.055 0.021 ref. 0.010 0.018 0° 8° FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-17 Package Outlines (continued) DIMENSIONS, DFN2x2-8L E A c A1 1 Nd D1 2 D b1 Exposed Thermal Pad Zone L h E1 h 2 e Symbol Min. 0.70 A A1 b b1 c D D1 Nd E E1 e L h 0.20 0.18 1.90 1.10 1.90 0.60 0.30 0.15 Millimeters Nom. 0.75 0.02 0.25 0.18 REF 0.20 2.00 1.20 1.50BSC 2.00 0.70 0.50BSC 0.35 0.20 1 b BOTTOM VIEW RECOMMENDED SOLDERING FOOTPRINT, DFN2x2-8L 1.60 0.0630 PACKAGE OUTLINE 8X 0.50 0.0197 1.00 0.0394 2.30 0.0906 1 0.50 PITCH 0.0197 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. 0.30 8X 0.0118 mm ( inches ) Max. 0.80 0.05 0.30 0.25 2.10 1.30 2.10 0.80 0.40 0.25 FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-18 Package Outlines (continued) DIMENSIONS, SOIC-8L A2 A A1 D b Symbol e A A1 A2 b C D E E1 e L θ L E E1 θ Dimensions In Millimeters Min Max 1.370 1.670 0.070 0.170 1.300 1.500 0.306 0.506 0.203 TYP. 4.700 5.100 3.820 4.020 5.800 6.200 1.270 TYP. 0.450 0.750 0° 8° Dimensions In Inches Min Max 0.054 0.066 0.003 0.007 0.051 0.059 0.012 0.020 0.008 TYP. 0.185 0.201 0.150 0.158 0.228 0.244 0.050 TYP. 0.018 0.030 0° 8° C RECOMMENDED SOLDERING FOOTPRINT, SOIC-8L 8X 5.40 0.213 (1.55) MAX (0.061) (3.90) MIN (0.154) 1 (0.60) MAX 8X (0.024) PITCH 1.270 0.050 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. mm ( inches ) FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-19 Package Outlines (continued) DIMENSIONS, MSOP-8L A2 A A1 D b Symbol e A A1 A2 b C D E E1 e L θ L E1 E Dimensions In Millimeters Min Max 0.800 1.100 Dimensions In Inches Min Max 0.031 0.043 0.050 0.150 0.750 0.950 0.290 0.380 0.150 0.200 2.900 3.100 2.900 3.100 4.700 5.100 0.650 TYP. 0.400 0.700 0° 8° 0.002 0.006 0.030 0.037 0.011 0.015 0.006 0.008 0.114 0.122 0.114 0.122 0.185 0.201 0.026 TYP. 0.016 0.028 0° 8° θ C RECOMMENDED SOLDERING FOOTPRINT, MSOP-8L 8X (0.45) MAX (0.018) (1.45) MAX (0.057) 8X 4.40 (5.85) MAX 0.173 (0.230) (2.95) MIN (0.116) 0.65 PITCH 0.026 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. mm ( inches ) FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-20 Package Outlines (continued) DIMENSIONS, TSSOP-8L A3 A2 A A1 Symbol D b C e L1 L E E1 A A1 A2 A3 b C D E E1 e L1 L θ Dimensions In Millimeters Min Max 1.200 0.020 0.150 0.900 1.050 0.390 0.490 0.200 0.290 0.130 0.180 2.900 3.100 6.200 6.600 4.300 4.500 0.650 typ. 1.000 ref. 0.450 0.750 0° 8° Dimensions In Inches Min Max 0.047 0.001 0.006 0.035 0.041 0.015 0.019 0.008 0.011 0.005 0.007 0.114 0.122 0.244 0.260 0.169 0.177 0.026 typ. 0.039 ref. 0.018 0.030 0° 8° θ RECOMMENDED SOLDERING FOOTPRINT, TSSOP-8L 8X (1.45) MAX (0.057) (4.40) MIN (0.173) PITCH 0.65 0.026 8X 5.90 0.232 (0.45) MAX (0.018) mm ( inches ) CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-21 Package Outlines (continued) DIMENSIONS, SOIC-14L A3 A2 A A1 D b C e L1 L E Symbol E1 A A1 A2 A3 b C D E E1 e L1 L θ Dimensions In Millimeters Min Max 1.450 1.850 0.100 0.300 1.350 1.550 0.550 0.750 0.406 TYP. 0.203 TYP. 8.630 8.830 5.840 6.240 3.850 4.050 1.270 TYP. 1.040 REF. 0.350 0.750 2° 8° Dimensions In Inches Min Max 0.057 0.073 0.004 0.012 0.053 0.061 0.022 0.030 0.016 TYP. 0.008 TYP. 0.340 0.348 0.230 0.246 0.152 0.159 0.050 TYP. 0.041 REF. 0.014 0.030 2° 8° θ RECOMMENDED SOLDERING FOOTPRINT, SOIC-14L 14X 5.40 0.213 (1.50) MAX (0.059) (3.90) MIN (0.154) 1 (0.60) MAX 14X (0.024) PITCH 1.270 0.050 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. mm ( inches ) FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-22 Package Outlines DIMENSIONS, QFN3x3-16L SIDE VIEW A TOP VIEW Symbol A3 D A A3 b D D1 E E1 e h K L BOTTOM VIEW K 9 L 12 8 E 13 E1 e D1 h 5 16 PIN#1 4 Min. 0.70 0.20 2.90 1.60 2.90 1.60 0.20 0.225 0.35 Millimeters Nom. 0.75 0.210 REF. 0.25 3.00 1.65 3.00 1.65 0.50 BSC. 0.25 0.275 0.40 1 b RECOMMENDED SOLDERING FOOTPRINT, QFN3x3-16L 0.65 0.20 3.50 1.70 1.70 1.80 0.30 0.25 0.50 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. Max. 0.80 0.30 3.10 1.70 3.10 1.70 0.30 0.325 0.45 FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers LTC725, LTC726, LTC727, LTC728 P-23 Package Outlines (continued) DIMENSIONS, TSSOP-14L A3 A2 A Symbol A1 D b e C L1 L E E1 A A1 A2 A3 b C D E E1 e L1 L θ Dimensions In Millimeters Min Max 1.200 0.050 0.150 0.900 1.050 0.390 0.490 0.200 0.290 0.130 0.180 4.860 5.060 6.200 6.600 4.300 4.500 0.650 TYP. 1.000 REF. 0.450 0.750 0° 8° Dimensions In Inches Min Max 0.047 0.002 0.006 0.035 0.041 0.015 0.019 0.008 0.011 0.005 0.007 0.191 0.199 0.244 0.260 0.169 0.177 0.026 TYP. 0.039 REF. 0.018 0.030 0° 8° θ RECOMMENDED SOLDERING FOOTPRINT, TSSOP-14L 14X (1.45) MAX (0.057) (4.40) MIN (0.173) PITCH 0.65 0.026 1 5.90 0.232 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. 14X (0.45) MAX (0.018) mm ( inches ) FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers P-24 LTC725, LTC726, LTC727, LTC728 IMPORTANT NOTICE Linearin is a global fabless semiconductor company specializing in advanced high-performance highquality analog/mixed-signal IC products and sensor solutions. The company is devoted to the innovation of high performance, analog-intensive sensor front-end products and modular sensor solutions, applied in multi-market of medical & wearable devices, smart home, sensing of IoT, and intelligent industrial & smart factory (industrie 4.0). Linearin’s product families include widely-used standard catalog products, solution-based application specific standard products (ASSPs) and sensor modules that help customers achieve faster time-to-market products. Go to http://www.linearin.com for a complete list of Linearin product families. For additional product information, or full datasheet, please contact with the Linearin’s Sales Department or Representatives. CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. Linearin and designs are registered trademarks of Linearin Technology Corporation. © Copyright Linearin Technology Corporation. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. FN1617-41T.3 — Data Sheet Precision, 11MHz, Low-Noise, RRIO, CMOS Amplifiers
LTC728XT14/R6 价格&库存

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LTC728XT14/R6
  •  国内价格
  • 1+8.40000
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库存:237