TSX711, TSX712 Low-power, precision, rail-to-rail, 2.7 MHz, 16 V CMOS operational amplifiers Datasheet - production data See the TSX921 and TSX922 for higher speeds Applications Battery-powered instrumentation Instrumentation amplifier Active filtering DAC buffer High-impedance sensor interface Current sensing (high and low side) Description Features Low input offset voltage: 200 µV max. Rail-to-rail input and output Low current consumption: 800 µA max. Gain bandwidth product: 2.7 MHz Low supply voltage: 2.7 - 16 V Unity gain stable Low input bias current: 50 pA max. High ESD tolerance: 4 kV HBM Extended temp. range: -40 °C to 125 °C Automotive qualification Related products See the TSX7191 and TSX7192 for higher speeds with similar precision See the TSX561 and TSX562 for low-power features See the TSX631 and TSX632 for micropower features January 2016 The TSX711 and TSX712 series of operational amplifiers (op amps) offer high precision functioning with low input offset voltage down to a maximum of 200 µV at 25 °C. In addition, their rail-to-rail input and output functionality allow these products to be used on full range input and output without limitation. This is particularly useful for a low-voltage supply such as 2.7 V that the TSX71x is able to operate with. Thus, the TSX71x has the great advantage of offering a large span of supply voltages, ranging from 2.7 V to 16 V. They can be used in multiple applications with a unique reference. Low input bias current performance makes the TSX71x perfect when used for signal conditioning in sensor interface applications. In addition, lowside and high-side current measurements can be easily made thanks to rail-to-rail functionality. High ESD tolerance (4 kV HBM) and a wide temperature range are also good arguments to use the TSX71x in the automotive market segment. DocID025959 Rev 4 This is information on a product in full production. 1/30 www.st.com Contents TSX711, TSX712 Contents 1 Package pin connections................................................................ 3 2 Absolute maximum ratings and operating conditions ................. 4 3 4 Electrical characteristics ................................................................ 5 Electrical characteristic curves .................................................... 11 5 Application information ................................................................ 17 6 5.1 Operating voltages .......................................................................... 17 5.2 Input pin voltage ranges .................................................................. 17 5.3 Rail-to-rail input ............................................................................... 17 5.4 Rail-to-rail output ............................................................................. 17 5.5 Input offset voltage drift over temperature ....................................... 18 5.6 Long term input offset voltage drift .................................................. 18 5.7 High values of input differential voltage ........................................... 19 5.8 Capacitive load................................................................................ 20 5.9 PCB layout recommendations ......................................................... 21 5.10 Optimized application recommendation .......................................... 21 5.11 Application examples ...................................................................... 21 5.11.1 Oxygen sensor ................................................................................. 21 5.11.2 Low-side current sensing.................................................................. 22 Package information ..................................................................... 24 6.1 SOT23-5 package information ........................................................ 25 6.2 MiniSO8 package information ......................................................... 26 6.3 SO8 package information ................................................................ 27 7 Ordering information..................................................................... 28 8 Revision history ............................................................................ 29 2/30 DocID025959 Rev 4 TSX711, TSX712 1 Package pin connections Package pin connections Figure 1: Pin connections (top view) DocID025959 Rev 4 3/30 Absolute maximum ratings and operating conditions 2 TSX711, TSX712 Absolute maximum ratings and operating conditions Table 1: Absolute maximum ratings (AMR) Symbol VCC Parameter Supply voltage (1) Vid Differential input voltage Vin Input voltage Iin Input current (2) (3) Tstg Storage temperature Rthja Thermal resistance junction to (4)(5) ambient Tj ESD MM: machine model Unit 18 V ±VCC mV (VCC-) - 0.2 to (VCC+) + 0.2 V 10 mA -65 to 150 °C SOT23-5 250 MiniSO8 190 SO8 125 Maximum junction temperature HBM: human body model Value 150 (6) °C/W °C 4000 (7) 100 CDM: charged device model (8) V 1500 Latch-up immunity 200 mA Notes: (1) All voltage values, except the differential voltage are with respect to the network ground terminal. (2) Differential voltages are the non-inverting input terminal with respect to the inverting input terminal. See Section 5.7 for the precautions to follow when using the TSX711 and TSX712 with a high differential input voltage. (3) (4) (5) (6) (7) (8) Input current must be limited by a resistor in series with the inputs. Rth are typical values. Short-circuits can cause excessive heating and destructive dissipation. According to JEDEC standard JESD22-A114F. According to JEDEC standard JESD22-A115A. According to ANSI/ESD STM5.3.1 Table 2: Operating conditions Symbol 4/30 Parameter VCC Supply voltage Vicm Common mode input voltage range Toper Operating free air temperature range Value 2.7 to 16 DocID025959 Rev 4 (VCC-) - 0.1 to (VCC+) + 0.1 -40 to 125 Unit V °C TSX711, TSX712 3 Electrical characteristics Electrical characteristics Table 3: Electrical characteristics at VCC+ = 4 V with VCC- = 0 V, Vicm = VCC/2, Tamb = 25 ° C, and RL > 10 kΩ connected to VCC/2 (unless otherwise specified) Symbol Parameter Conditions Vio (TSX711, TSX712) Input offset voltage Vio (TSX711A) ΔVio/ΔT ΔVio Iib Input offset voltage drift (1) Iio Input offset current RIN Input resistance CIN Input capacitance (1) Common mode rejection ratio 20 log (ΔVic/ΔVio) CMRR (TSX712) Large signal voltage gain 200 Tmin < Top < 85 °C 365 Tmin < Top < 125 °C 450 Vicm = VCC/2 100 Tmin < Top < 85 °C 265 Tmin < Top < 125 °C 350 2.5 High level output voltage (voltage drop from VCC+) Unit μV µV/°C nV month --------------------------- T = 25 °C 1 Vout = VCC/2 1 1 Tmin < Top < Tmax 84 Tmin < Top < Tmax 83 Vicm = -0.1 to 2 V, Vout = VCC/2 100 Tmin < Top < Tmax 94 Vicm = -0.1 to 4.1 V, Vout = VCC/2 80 Tmin < Top < Tmax 78 Vicm = -0.1 to 2 V, Vout = VCC/2 91 Tmin < Top < Tmax 86 RL= 2 kΩ, Vout = 0.3 to 3.7 V 110 Tmin < Top < Tmax 96 RL= 10 kΩ, Vout = 0.2 to 3.8 V 110 Tmin < Top < Tmax 96 DocID025959 Rev 4 pA 1 TΩ 12.5 pF 102 122 98 dB 103 136 140 28 Tmin < Top < Tmax Tmin < Top < Tmax 50 200 Vicm = -0.1 to 4.1 V, Vout = VCC/2 RL= 10 kΩ tο VCC/2 50 200 Vout = VCC/2 RL= 2 kΩ to VCC/2 VOH Max. Vicm = VCC/2 Tmin < Top < Tmax CMRR (TSX711) Avd Typ. (1) Long term input offset (2) voltage drift Input bias current Min. 50 60 6 15 mV 20 5/30 Electrical characteristics Symbol TSX711, TSX712 Parameter Conditions Min. RL= 2 kΩ tο VCC/2 VOL Low level output voltage Typ. Max. 23 50 Tmin < Top < Tmax 60 RL= 10 kΩ tο VCC/2 5 Tmin < Top < Tmax Isink Iout (TSX711) Isource Isink Iout (TSX712) Isource 35 Tmin < Top < Tmax 20 Vout = 0 V 35 Tmin < Top < Tmax 20 Vout = VCC 25 Tmin < Top < Tmax 15 Vout = 0 V 35 Tmin < Top < Tmax 20 No load, Vout = VCC/2 Gain bandwidth product RL = 10 kΩ, CL = 100 pF ɸm Phase margin Gm GBP SRn SRp en THD+N mV 20 Vout = VCC Supply current per amplifier ICC 15 Unit 45 45 mA 37 45 570 Tmin < Top < Tmax 800 μA 900 2.7 MHz RL = 10 kΩ, CL = 100 pF 50 Degrees Gain margin RL = 10 kΩ, CL = 100 pF 15 dB Negative slew rate Av = 1, Vout = 3 VPP, 10 % to 90 % 0.6 Tmin < Top < Tmax 0.5 Av = 1, Vout = 3VPP, 10 % to 90 % 1.0 Tmin < Top < Tmax 0.9 Positive slew rate 1.9 0.85 V/μs 1.4 f = 1 kHz 22 Equivalent input noise voltage f = 10 kHz 19 Total harmonic distortion + noise f =1 kHz, Av = 1, RL= 10 kΩ, BW = 22 kHz, Vin= 0.8 VPP nV -----------Hz 0.001 Notes: (1) Maximum values are guaranteed by design. (2) Typical value is based on the Vio drift observed after 1000h at 125 °C extrapolated to 25 °C using the Arrhenius law and assuming an activation energy of 0.7 eV. The operational amplifier is aged in follower mode configuration (see Section 5.6). 6/30 DocID025959 Rev 4 % TSX711, TSX712 Electrical characteristics Table 4: Electrical characteristics at VCC+ = 10 V with VCC- = 0 V, Vicm = VCC/2, Tamb = 25 °C, and RL > 10 kΩ connected to VCC/2 (unless otherwise specified) Symbol Parameter Conditions Vio (TSX711, TSX712) Input offset voltage Vio (TSX711A) ΔVio/ΔT ΔVio Iib Input offset voltage drift (1) Iio Input offset current RIN Input resistance CIN Input capacitance (1) Common mode rejection ratio 20 log (ΔVic/ΔVio) CMRR (TSX712) Large signal voltage gain 200 Tmin < Top < 85 °C 365 Tmin < Top < 125 °C 450 Vicm = VCC/2 100 Tmin < Top < 85 °C 265 Tmin < Top < 125 °C 350 2.5 T = 25 °C 25 Vout = VCC/2 1 High level output voltage (voltage drop from VCC+) 1 Tmin < Top < Tmax 90 Tmin < Top < Tmax 86 Vicm = -0.1 to 8 V, Vout = VCC/2 105 Tmin < Top < Tmax 95 Vicm = -0.1 to 10.1 V, Vout = VCC/2 88 Tmin < Top < Tmax 84 Vicm = -0.1 to 8 V, Vout = VCC/2 98 Tmin < Top < Tmax 92 RL= 2 kΩ, Vout = 0.3 to 9.7 V 110 Tmin < Top < Tmax 100 RL= 10 kΩ, Vout = 0.2 to 9.8 V 110 Tmin < Top < Tmax 100 Low level output voltage Tmin < Top < Tmax DocID025959 Rev 4 50 50 pA 12.5 pF 102 117 100 dB 106 140 45 70 80 10 30 40 42 Tmin < Top < Tmax RL= 10 kΩ ο VCC/2 nV month TΩ Tmin < Top < Tmax VOL μV/°C 1 Tmin < Top < Tmax RL= 2 kΩ ο VCC/2 μV 200 Vicm = -0.1 to 10.1 V, Vout = VCC/2 RL= 10 kΩ ο VCC/2 Unit --------------------------- 200 Vout = VCC/2 RL= 2 kΩ ο VCC/2 VOH Max. Vicm = VCC/2 Tmin < Top < Tmax CMRR (TSX711) Avd Typ. (1) Long term input offset (2) voltage drift Input bias current Min. 70 mV 80 9 30 40 7/30 Electrical characteristics Symbol TSX711, TSX712 Parameter Isink Iout (TSX711) Isource Isink Iout (TSX712) Isource Conditions Min. Typ. Vout = VCC 50 70 Tmin < Top < Tmax 40 Vout = 0 V 50 Tmin < Top < Tmax 40 Vout = VCC 30 Tmin < Top < Tmax 15 Vout = 0 V 50 Tmin < Top < Tmax 40 Supply current per amplifier No load, Vout = VCC/2 Gain bandwidth product RL = 10 kΩ, CL = 100 pF ɸm Phase margin Gm ICC GBP SRn SRp en THD+N Max. Unit 69 mA 39 69 630 Tmin < Top < Tmax 850 μA 1000 2.7 MHz RL = 10 kΩ, CL = 100 pF 53 Degrees Gain margin RL = 10 kΩ, CL = 100 pF 15 dB Negative slew rate Av = 1, Vout = 8 VPP, 10 % to 90 % 0.8 Tmin < Top < Tmax 0.7 Av = 1, Vout = 8 VPP, 10 % to 90 % 1.0 Tmin < Top < Tmax 0.9 Positive slew rate 1.9 1 V/μs 1.3 f = 1 kHz 22 Equivalent input noise voltage f = 10 kHz 19 Total harmonic distortion + noise f = 1 kHz, Av = 1, RL= 10 kΩ, BW = 22 kHz, Vin= 5 VPP nV -----------Hz 0.0003 Notes: (1) Maximum values are guaranteed by design. (2) Typical value is based on the Vio drift observed after 1000h at 125 °C extrapolated to 25 °C using the Arrhenius law and assuming an activation energy of 0.7 eV. The operational amplifier is aged in follower mode configuration (see Section 5.6). 8/30 DocID025959 Rev 4 % TSX711, TSX712 Electrical characteristics Table 5: Electrical characteristics at VCC+ = 16 V with VCC- = 0 V, Vicm = VCC/2, Tamb = 25 °C, and RL > 10 kΩ connected to VCC/2 (unless otherwise specified) Symbol Parameter Conditions Vio (TSX711, TSX712) Input offset voltage Vio (TSX711A) ΔVio/ΔT ΔVio Input offset voltage drift (1) Input bias current Iio Input offset current RIN Input resistance CIN Input capacitance (1) Common mode rejection ratio 20 log (ΔVic/ΔVio) CMRR (TSX712) Avd Supply voltage rejection ratio 20 log (ΔVcc/ΔVio) Large signal voltage gain Max. Vicm = VCC/2 200 Tmin < Top < 85 °C 365 Tmin < Top < 125 °C 450 Vicm = VCC/2 100 Tmin < Top < 85 °C 265 Tmin < Top < 125 °C 350 2.5 T = 25 °C Vout = VCC/2 1 1 Tmin < Top < Tmax μV/°C 50 50 pA 200 Vicm = -0.1 to 16.1 V, Vout = VCC/2 94 Tmin < Top < Tmax 90 Vicm = -0.1 to 14 V, Vout = VCC/2 110 Tmin < Top < Tmax 96 Vicm = -0.1 to 16.1 V, Vout = VCC/2 94 Tmin < Top < Tmax 90 Vicm = -0.1 to 14 V, Vout = VCC/2 100 Tmin < Top < Tmax 90 Vcc = 4 to 16 V 100 Tmin < Top < Tmax 90 RL= 2 kΩ, Vout = 0.3 to 15.7 V 110 Tmin < Top < Tmax 100 RL= 10 kΩ, Vout = 0.2 to 15.8 V 110 Tmin < Top < Tmax 100 DocID025959 Rev 4 μV nV month 200 Vout = VCC/2 Unit --------------------------- 500 Tmin < Top < Tmax CMRR (TSX711) SVRR Typ. (1) Long term input offset (2) voltage drift Iib Min. 1 TΩ 12.5 pF 113 116 107 dB 107 131 146 149 9/30 Electrical characteristics Symbol VOH TSX711, TSX712 Parameter High level output voltage (voltage drop from VCC+) Conditions Min. Typ. Max. RL= 2 kΩ (TSX711) 100 130 RL= 2 kΩ (TSX712) 70 130 Tmin < Top < Tmax 150 RL= 10 kΩ 16 40 70 130 Tmin < Top < Tmax Low level output voltage Tmin < Top < Tmax 150 RL= 10 kΩ 15 Tmin < Top < Tmax Isink Iout (TSX711) Isource Isink Iout (TSX712) Isource Vout = VCC 50 Tmin < Top < Tmax 45 Vout = 0 V 50 Tmin < Top < Tmax 45 Vout = VCC 30 Tmin < Top < Tmax 15 Vout = 0 V 50 Tmin < Top < Tmax 45 No load, Vout = VCC/2 Gain bandwidth product RL = 10 kΩ, CL = 100 pF ɸm Phase margin Gm Gain margin Negative slew rate Av = 1, Vout = 10 VPP, 10 % to 90 % 0.7 Tmin < Top < Tmax 0.6 GBP SRn SRp Positive slew rate THD+N mV 71 68 mA 40 68 660 Tmin < Top < Tmax 900 μA 1000 2.7 MHz RL = 10 kΩ, CL = 100 pF 55 Degrees RL = 10 kΩ, CL= 100 pF 15 dB Av = 1, Vout = 10 VPP, 10 % to 90 % Tmin < Top < Tmax en 40 50 Supply current per amplifier ICC mV 50 RL= 2 kΩ VOL Unit 1.9 1 0.95 V/μs 1.4 0.9 f = 1 kHz 22 Equivalent input noise voltage f = 10 kHz 19 Total harmonic distortion + Noise f = 1 kHz, Av = 1, RL= 10 kΩ, BW = 22 kHz, Vin= 10 VPP nV -----------Hz 0.0002 Notes: (1) Maximum values are guaranteed by design. (2) Typical value is based on the Vio drift observed after 1000h at 125 °C extrapolated to 25 °C using the Arrhenius law and assuming an activation energy of 0.7 eV. The operational amplifier is aged in follower mode configuration (see Section 5.6). 10/30 DocID025959 Rev 4 % TSX711, TSX712 Electrical characteristic curves Figure 2: Supply current vs. supply voltage Figure 3: Input offset voltage distribution at VCC = 16 V Figure 4: Input offset voltage distribution at VCC = 4 V Figure 5: Input offset voltage vs. temperature at VCC = 16 V 600 Vio limit 400 Input offset voltage (µV) 4 Electrical characteristic curves 200 0 -200 -400 -600 -40 Figure 6: Input offset voltage drift population Vcc=16V Vicm=8V -20 0 20 40 60 Temperature (°C) 80 100 120 Figure 7: Input offset voltage vs. supply voltage at VICM = 0 V DocID025959 Rev 4 11/30 Electrical characteristic curves TSX711, TSX712 Figure 8: Input offset voltage vs. common mode voltage at VCC = 2.7 V Figure 9: Input offset voltage vs. common mode voltage at VCC = 16 V Figure 10: Output current vs. output voltage at VCC = 2.7 V (TSX711) Figure 11: Output current vs. output voltage at VCC = 16 V (TSX711) Figure 12: Output current vs. output voltage at VCC = 2.7 V (TSX712) Figure 13: Output current vs. output voltage at VCC = 16 V (TSX712) 12/30 DocID025959 Rev 4 TSX711, TSX712 Electrical characteristic curves Figure 14: Output low voltage vs. supply voltage Figure 15: Output high voltage (drop from VCC+) vs. supply voltage Figure 16: Output voltage vs. input voltage close to the rail at VCC = 16 V Figure 17: Slew rate vs. supply voltage Figure 18: Negative slew rate at VCC = 16 V Figure 19: Positive slew rate at VCC = 16 V DocID025959 Rev 4 13/30 Electrical characteristic curves TSX711, TSX712 Figure 20: Response to a small input voltage step Figure 21: Recovery behavior after a negative step on the input Figure 22: Recovery behavior after a positive step on the input Figure 23: Bode diagram at VCC = 2.7 V Figure 24: Bode diagram at VCC = 16 V Figure 25: Power supply rejection ratio (PSRR) vs. frequency 14/30 DocID025959 Rev 4 TSX711, TSX712 Electrical characteristic curves Figure 26: Output overshoot vs. capacitive load Figure 27: Output impedance vs. frequency in closed loop configuration Figure 28: THD + N vs. frequency Figure 29: THD + N vs. output voltage Figure 30: Noise vs. frequency Figure 31: 0.1 to 10Hz noise DocID025959 Rev 4 15/30 Electrical characteristic curves TSX711, TSX712 Figure 32: Channel separation (TSX712) 16/30 DocID025959 Rev 4 TSX711, TSX712 Application information 5 Application information 5.1 Operating voltages The TSX711 and TSX712 devices can operate from 2.7 to 16 V. The parameters are fully specified for 4 V, 10 V, and 16 V power supplies. However, the parameters are very stable in the full VCC range. Additionally, the main specifications are guaranteed in extended temperature ranges from -40 to 125 °C. 5.2 Input pin voltage ranges The TSX711 and TSX712 devices have internal ESD diode protection on the inputs. These diodes are connected between the input and each supply rail to protect the input MOSFETs from electrical discharge. If the input pin voltage exceeds the power supply by 0.5 V, the ESD diodes become conductive and excessive current can flow through them. Without limitation this over current can damage the device. In this case, it is important to limit the current to 10 mA, by adding resistance on the input pin, as described in Figure 33: "Input current limitation". Figure 33: Input current limitation 16 V R Vin 5.3 - + + - Vout Rail-to-rail input The TSX711 and TSX712 devices have a rail-to-rail input, and the input common mode range is extended from (VCC-) - 0.1 V to (VCC+) + 0.1 V. 5.4 Rail-to-rail output The operational amplifier output levels can go close to the rails: to a maximum of 40 mV above and below the rail when connected to a 10 kΩ resistive load to V CC/2. DocID025959 Rev 4 17/30 Application information 5.5 TSX711, TSX712 Input offset voltage drift over temperature The maximum input voltage drift variation over temperature is defined as the offset variation related to the offset value measured at 25 °C. The operational amplifier is one of the main circuits of the signal conditioning chain, and the amplifier input offset is a major contributor to the chain accuracy. The signal chain accuracy at 25 °C can be compensated during production at application level. The maximum input voltage drift over temperature enables the system designer to anticipate the effect of temperature variations. The maximum input voltage drift over temperature is computed using Equation 1. Equation 1 ∆Vio V T – Vio 25 °C = max io ∆T T – 25 °C Where T = -40 °C and 125 °C. The TSX711 and TSX712 datasheet maximum values are guaranteed by measurements on a representative sample size ensuring a Cpk (process capability index) greater than 1.3. 5.6 Long term input offset voltage drift To evaluate product reliability, two types of stress acceleration are used: Voltage acceleration, by changing the applied voltage Temperature acceleration, by changing the die temperature (below the maximum junction temperature allowed by the technology) with the ambient temperature. The voltage acceleration has been defined based on JEDEC results, and is defined using Equation 2. Equation 2 AFV = e β . V S – VU Where: AFV is the voltage acceleration factor β is the voltage acceleration constant in 1/V, constant technology parameter (β = 1) VS is the stress voltage used for the accelerated test VU is the voltage used for the application The temperature acceleration is driven by the Arrhenius model, and is defined in Equation 3. Equation 3 AFT = e Ea 1 1 ------ . – k TU TS Where: AFT is the temperature acceleration factor Ea is the activation energy of the technology based on the failure rate 18/30 DocID025959 Rev 4 TSX711, TSX712 Application information -5 -1 k is the Boltzmann constant (8.6173 x 10 eV.K ) TU is the temperature of the die when VU is used (K) TS is the temperature of the die under temperature stress (K) The final acceleration factor, AF, is the multiplication of the voltage acceleration factor and the temperature acceleration factor (Equation 4). Equation 4 AF = AFT × AFV AF is calculated using the temperature and voltage defined in the mission profile of the product. The AF value can then be used in Equation 5 to calculate the number of months of use equivalent to 1000 hours of reliable stress duration. Equation 5 Months = AF × 1000 h × 12 months / 24 h × 365.25 days To evaluate the op amp reliability, a follower stress condition is used where V CC is defined as a function of the maximum operating voltage and the absolute maximum rating (as recommended by JEDEC rules). The Vio drift (in µV) of the product after 1000 h of stress is tracked with parameters at different measurement conditions (see Equation 6). Equation 6 VCC = maxVop with Vicm = VCC 2 The long term drift parameter (ΔVio), estimating the reliability performance of the product, is obtained using the ratio of the Vio (input offset voltage value) drift over the square root of the calculated number of months (Equation 7). Equation 7 ∆Vio = Vio dr ift month s Where Vio drift is the measured drift value in the specified test conditions after 1000 h stress duration. 5.7 High values of input differential voltage In a closed loop configuration, which represents the typical use of an op amp, the input differential voltage is low (close to Vio). However, some specific conditions can lead to higher input differential values, such as: operation in an output saturation state operation at speeds higher than the device bandwidth, with output voltage dynamics limited by slew rate. use of the amplifier in a comparator configuration, hence in open loop Use of the TSX711 or TSX712 in comparator configuration, especially combined with high temperature and long duration can create a permanent drift of Vio. DocID025959 Rev 4 19/30 Application information 5.8 TSX711, TSX712 Capacitive load Driving large capacitive loads can cause stability problems. Increasing the load capacitance produces gain peaking in the frequency response, with overshoot and ringing in the step response. It is usually considered that with a gain peaking higher than 2.3 dB an op amp might become unstable. Generally, the unity gain configuration is the worst case for stability and the ability to drive large capacitive loads. Figure 34: "Stability criteria with a serial resistor at different supply voltage" shows the serial resistor that must be added to the output, to make a system stable. Figure 35: "Test configuration for Riso" shows the test configuration using an isolation resistor, Riso. Figure 34: Stability criteria with a serial resistor at different supply voltage 1000 Vcc=16V Riso (Ω) Stable Vcc=2.7V 100 Unstable Vicm=Vcc/2 Rl=10kΩ Gain=1 T=25°C 10 100 p 1n 10 n 100 n Cload (F) Figure 35: Test configuration for Riso V CC+ Riso VIN + Cload V CC- 20/30 DocID025959 Rev 4 VOUT 10 kΩ TSX711, TSX712 5.9 Application information PCB layout recommendations Particular attention must be paid to the layout of the PCB, tracks connected to the amplifier, load, and power supply. The power and ground traces are critical as they must provide adequate energy and grounding for all circuits. The best practice is to use short and wide PCB traces to minimize voltage drops and parasitic inductance. In addition, to minimize parasitic impedance over the entire surface, a multi-via technique that connects the bottom and top layer ground planes together in many locations is often used. The copper traces that connect the output pins to the load and supply pins should be as wide as possible to minimize trace resistance. 5.10 Optimized application recommendation It is recommended to place a 22 nF capacitor as close as possible to the supply pin. A good decoupling will help to reduce electromagnetic interference impact. 5.11 Application examples 5.11.1 Oxygen sensor The electrochemical sensor creates a current proportional to the concentration of the gas being measured. This current is converted into voltage thanks to R resistance. This voltage is then amplified by the TSX711 or the TSX712 (see Figure 36: "Oxygen sensor principle schematic"). Figure 36: Oxygen sensor principle schematic R1 R2 VCC I O2_ sensor + + Vout - The output voltage is calculated using Equation 8: Equation 8 Vou t = I × R – Vio × R2 +1 R1 As the current delivered by the O2 sensor is extremely low, the impact of the V io can become significant with a traditional operational amplifier. The use of a precision amplifier like the TSX711/TSX712 is perfect for this application. In addition, using the TSX711/TSX712 for the O2 sensor application ensures that the measurement of O2 concentration is stable, even at different temperatures, thanks to a small ΔVio/ΔT. DocID025959 Rev 4 21/30 Application information 5.11.2 TSX711, TSX712 Low-side current sensing Power management mechanisms are found in most electronic systems. Current sensing is useful for protecting applications. The low-side current sensing method consists of placing a sense resistor between the load and the circuit ground. The resulting voltage drop is amplified using the TSX711 or TSX712 (see Figure 37: "Low-side current sensing schematic"). Figure 37: Low-side current sensing schematic C1 Rg1 I Rf1 In Rshunt Rg2 Ip 5V - + + - Vout Rf2 Vout can be expressed as follows: Equation 9 Vou t = Rshun t × I 1 – Rg2 Rg2 + Rf2 1+ Rg2 × Rf2 Rf1 Rf1 Rf1 + Ip – l n × Rf1 – Vio 1 + × 1+ Rg2 + Rf2 Rg1 Rg1 Rg1 Assuming that Rf2 = Rf1 = Rf and Rg2 = Rg1 = Rg, Equation 9 can be simplified as follows: Equation 10 Vout = Rshunt × I Rf Rf – Vio 1 + + Rf × I io Rg Rg The main advantage of using a precision amplifier like the TSX711 or TSX712, for a low-side current sensing, is that the errors due to Vio and Iio are extremely low and may be neglected. Therefore, for the same accuracy, the shunt resistor can be chosen with a lower value, resulting in lower power dissipation, lower drop in the ground path, and lower cost. Particular attention must be paid on the matching and precision of Rg1, Rg2, Rf1, and Rf2, to maximize the accuracy of the measurement. Taking into consideration the resistor inaccuracies, the maximum and minimum output voltage of the operational amplifier can be calculated respectively using Equation 11 and Equation 12. 22/30 DocID025959 Rev 4 TSX711, TSX712 Application information Equation 11 Maximum Vout = Rshunt × I × Rf Rf × 1 + ε rs + 2ε r + Vi o × 1 + + Rf × li o Rg Rg Equation 12 Minimum Vout = Rshunt × I × Rf Rf × 1 – ε rs – 2ε r – Vi o × 1 + + Rf × lio Rg Rg Where: εrs is the shunt resistor inaccuracy (example, 1 % ) εr is the inaccuracy of the Rf and Rg resistors (example, 0.1 %) DocID025959 Rev 4 23/30 Package information 6 TSX711, TSX712 Package information In order to meet environmental requirements, ST offers these devices in different grades of ® ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ® ECOPACK is an ST trademark. 24/30 DocID025959 Rev 4 TSX711, TSX712 6.1 Package information SOT23-5 package information Figure 38: SOT23-5 package outline Table 6: SOT23-5 mechanical data Dimensions Ref. A Millimeters Inches Min. Typ. Max. Min. Typ. Max. 0.90 1.20 1.45 0.035 0.047 0.057 A1 0.15 0.006 A2 0.90 1.05 1.30 0.035 0.041 0.051 B 0.35 0.40 0.50 0.014 0.016 0.020 C 0.09 0.15 0.20 0.004 0.006 0.008 D 2.80 2.90 3.00 0.110 0.114 0.118 D1 1.90 0.075 e 0.95 0.037 E 2.60 2.80 3.00 0.102 0.110 0.118 F 1.50 1.60 1.75 0.059 0.063 0.069 L 0.10 0.35 0.60 0.004 0.014 0.024 K 0 degrees 10 degrees 0 degrees DocID025959 Rev 4 10 degrees 25/30 Package information 6.2 TSX711, TSX712 MiniSO8 package information Figure 39: MiniSO8 package outline Table 7: MiniSO8 mechanical data Dimensions Ref. Millimeters Min. Typ. A 0 Min. Typ. A2 0.75 b 0.22 c 0.08 D 2.80 E E1 0.043 0 0.95 0.030 0.40 0.009 0.016 0.23 0.003 0.009 3.00 3.20 0.11 0.118 0.126 4.65 4.90 5.15 0.183 0.193 0.203 2.80 3.00 3.10 0.11 0.118 0.122 0.85 0.65 0.40 0.60 0.006 0.033 0.80 0.016 0.024 0.95 0.037 L2 0.25 0.010 ccc 0° 0.037 0.026 L1 k Max. 0.15 e 26/30 Max. 1.1 A1 L Inches 8° 0.10 DocID025959 Rev 4 0° 0.031 8° 0.004 TSX711, TSX712 6.3 Package information SO8 package information Figure 40: SO8 package outline Table 8: SO8 mechanical data Dimensions Ref. Millimeters Min. Typ. A Inches Max. Min. Typ. 1.75 0.069 A1 0.10 A2 1.25 b 0.28 0.48 0.011 0.019 c 0.17 0.23 0.007 0.010 D 4.80 4.90 5.00 0.189 0.193 0.197 E 5.80 6.00 6.20 0.228 0.236 0.244 E1 3.80 3.90 4.00 0.150 0.154 0.157 e 0.25 Max 0.004 0.010 0.049 1.27 0.050 h 0.25 0.50 0.010 0.020 L 0.40 1.27 0.016 0.050 L1 k ccc 1.04 1° 0.040 8° 0.10 DocID025959 Rev 4 1° 8° 0.004 27/30 Ordering information 7 TSX711, TSX712 Ordering information Table 9: Order codes Order code Temperature range TSX711ILT Packaging (1) (1) TSX711AIYLT TSX712IDT TSX712IST TSX712IYDT (2) TSX712IYST (2) K195 SΟΤ23-5 K197 -40 to 125 °C (automotive grade) -40 to 125 °C -40 to 125 °C (automotive grade) Marking K29 -40 to 125 °C TSX711AILT TSX711IYLT Package SO8 Tape and reel K198 TSX712 MiniSO8 K211 SO8 TSX712Y MiniSO8 K212 Notes: (1) Qualification and characterization according to AEC Q100 and Q003 or equivalent, advanced screening according to AEC Q001 & Q 002 or equivalent are on-going. (2) Qualification and characterization according to AEC Q100 and Q003 or equivalent, advanced screening according to AEC Q001 & Q 002 or equivalent. 28/30 DocID025959 Rev 4 TSX711, TSX712 8 Revision history Revision history Table 10: Document revision history Date Revision 27-Feb-2014 1 Initial release 19-Mar-2014 2 Table 1: updated ESD data for MM (machine model) 3 Table 3: updated Iout (Isink) values. Table 3, Table 4, and Table 5: updated Vio values, updated ΔVio/ΔT. Table 5: updated VOL values Table 6: updated “inches” dimensions 4 TSX711 datasheet merged with TSX712 datasheet. Reworked the following sections: Cover image, Related products, Description, Section 1: "Package pin connections", Section 2: "Absolute maximum ratings and operating conditions", Section 3: "Electrical characteristics", Section 4: "Electrical characteristic curves", Section 5.1: "Operating voltages", Section 5.2: "Input pin voltage ranges", Section 5.3: "Rail-torail input", Section 5.4: "Rail-to-rail output", Section 5.5: "Input offset voltage drift over temperature", Section 5.7: "High values of input differential voltage", Section 5.11.1: "Oxygen sensor", Section 5.11.2: "Low-side current sensing", Section 7: "Ordering information". Added: Section 6.2: "MiniSO8 package information" and Section 6.3: "SO8 package information" 25-Jul-2014 26-Jan-2016 Changes DocID025959 Rev 4 29/30 TSX711, TSX712 IMPORTANT NOTICE – PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST’s terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers’ products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. © 2016 STMicroelectronics – All rights reserved 30/30 DocID025959 Rev 4