INA170EA/2K5

INA170 SBOS193D – MARCH 2001 – REVISED JANUARY 2006 High-Side, Bidirectional CURRENT SHUNT MONITOR FEATURES DESCRIPTION ● COMPLETE BIDIRECTIONAL CURRENT MEASUREMENT CIRCUIT ● WIDE SUPPLY RANGE: 2.7V to 40V ● SUPPLY-INDEPENDENT COMMON-MODE VOLTAGE: 2.7V TO 60V ● RESISTOR PROGRAMMABLE GAIN SET ● LOW QUIESCENT CURRENT: 75µA (typ) ● MSOP-8 PACKAGE The INA170 is a high-side, bidirectional current shunt monitor featuring a wide input common-mode voltage range, low quiescent current, and a tiny MSOP-8 package. Bidirectional current measurement is accomplished by output offsetting. The offset voltage level is set with an external resistor and voltage reference. This permits measurement of a bidirectional shunt current while using a single supply for the INA170. Input common-mode and power-supply voltages are independent. Input voltage can range from +2.7V to +60V on any supply voltage from +2.7V to +40V. Low 10µA input bias current adds minimal error to the shunt current. APPLICATIONS ● CURRENT SHUNT MEASUREMENT: Automotive, Telephone, Computers, Power Systems, Test, General Instrumentation ● PORTABLE AND BATTERY-BACKUP SYSTEMS ● BATTERY CHARGERS ● POWER MANAGEMENT ● CELL PHONES The INA170 converts a differential input voltage to a current output. This current develops a voltage across an external load resistor, setting any gain from 1 to over 100. The INA170 is available in an MSOP-8 package, and is specified over the extended industrial temperature range, –40°C to +85°C with operation from –55°C to +125°C. V+ VSUPPLY 8 + VIN IS RS RG1 1kΩ 2 – VIN RG2 1kΩ 1 VREF Q1 6 OUT 3 Load A2 ROS A1 Q2 RL INA170 5 GND ROS 4 Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. All trademarks are the property of their respective owners. Copyright © 2001-2006, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. www.ti.com ABSOLUTE MAXIMUM RATINGS(1) ELECTROSTATIC DISCHARGE SENSITIVITY Supply Voltage, V+ to GND ................................................. –0.3V to 40V Analog Inputs, Common Mode(2) ......................................... –0.3V to 75V + – Differential (VIN ) – (VIN ) .................................. –40V to 2V Analog Output, Out(2) ........................................................... –0.3V to 40V Input Current Into Any Pin ............................................................... 10mA Operating Temperature .................................................. –55°C to +125°C Storage Temperature ..................................................... –65°C to +150°C Junction Temperature .................................................................... +150°C This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications. NOTE: (1) Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied. (2) The input voltage at any pin may exceed the voltage shown if the current at that pin is limited to 10mA. PACKAGE/ORDERING INFORMATION(1) SPECIFIED TEMPERATURE RANGE PACKAGE MARKING PRODUCT PACKAGE-LEAD PACKAGE DESIGNATOR INA170EA MSOP-8 DGK –40°C to +85°C INA170EA INA170EA/250 Tape and Reel, 250 " " " " INA170EA/2K5 Tape and Reel, 2500 " ORDERING NUMBER TRANSPORT MEDIA, QUANTITY NOTE: (1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com. PIN CONFIGURATION PIN DESCRIPTION TOP VIEW 2 MSOP – VIN 1 8 V+ + VIN 2 7 NC VREF 3 6 OUT GND 4 5 ROS PIN DESIGNATOR 1 2 3 4 5 6 7 8 – VIN + VIN VREF GND ROS OUT NC V+ DESCRIPTION Inverting Input Noninverting Input Reference Voltage Input Ground Offset Resistor Output No Connection Supply Voltage INA170 www.ti.com SBOS193D ELECTRICAL CHARACTERISTICS + = 12V, R At TA = –40°C to +85°C, VS = 5V, VIN OUT = 25kΩ, unless otherwise noted. INA170EA PARAMETER INPUT Full-Scale Sense (Input) Voltage Common-Mode Input Range Common-Mode Rejection Offset Voltage(1) RTI vs Temperature vs Power Supply Input Bias Current OFFSETTING AMPLIFIER Offsetting Equation Input Voltage Input Offset Voltage vs Temperature Programming Current through ROS Input Impedance Input Bias Current OUTPUT Transconductance vs Temperature Nonlinearity Error Total Output Error Output Impedance Voltage Output Swing to Power Supply, V+ Swing to Common Mode, VCM FREQUENCY RESPONSE Bandwidth Settling Time (0.1%) NOISE Output-Current Noise Density Total Output-Current Noise POWER SUPPLY Operating Range Quiescent Current CONDITION MIN + – V– VSENSE = VIN IN + = +2.7V to +60V, V VIN SENSE = 50mV +2.7 100 TMIN to TMAX V+ = +2.7V to +60V, VSENSE = 50mV + , V– VIN IN TYP MAX UNITS 100 500 +60 mV V dB mV µV/°C µV/V uA 120 ±0.2 1 0.1 10 ±1 10 VOS = (RL/ROS) VREF 1 ±0.2 10 TMIN to TMAX 0 VS – 1 ±1 1 1010 || 4 +10 + , V– VIN IN VSENSE = 10mV to 150mV VSENSE = 100mV VSENSE = 10mV to 150mV VSENSE = 100mV 0.990 1 50 ±0.01 ±0.5 1 || 5 1.01 (V+) – 0.9 VCM – 0.6 (V+) – 1.2 VCM – 1.0 ±0.1 ±2 V mV µV/°C mA Ω || pF nA mA/V nA/°C % % GΩ || pF V V ROUT = 10kΩ 5V Step, ROUT = 10kΩ 400 3 kHz µs BW = 100kHz 20 7 pA/√Hz nA RMS V+ VSENSE = 0, IO = 0 TEMPERATURE RANGE Specification, TMIN to TMAX Operating Storage Thermal Resistance, θJA +2.7 75 –40 –55 –65 150 +40 125 V µA +85 +125 +150 °C °C °C °C/W NOTE: (1) Defined as the amount of input voltage, VSENSE, to drive the output to zero. INA170 SBOS193D www.ti.com 3 TYPICAL CHARACTERISTICS + = 12V, R = 25kΩ, unless otherwise noted. At TA = +25°C, V+ = 5V, VIN L COMMON-MODE REJECTION vs FREQUENCY GAIN vs FREQUENCY 40 120 Common-Mode Rejection (dB) RL = 100kΩ 30 RL = 10kΩ Gain (dB) 20 10 RL = 1kΩ 0 –10 –20 G = 100 100 80 G = 10 60 G=1 40 20 0 100 10k 1k 100k 10M 1M 0.1 10 1 Frequency (Hz) 100 5 + – V– ) VIN = (VIN IN 120 Total Output Error (%) Power-Supply Rejection (dB) –55°C G = 100 100 G = 10 80 G=1 60 0 +150°C –5 +25°C –10 40 –15 20 1 100 1k Frequency (Hz) 10 10k 0 100k 25 50 75 100 125 150 200 VIN (mV) TOTAL OUTPUT ERROR vs POWER-SUPPLY VOLTAGE QUIESCENT CURRENT vs POWER-SUPPLY VOLTAGE 2 100 Output error is essentially independent of both V+ supply voltage and input common-mode voltage. 1 +150° Quiescent Current (µA) Total Output Error (%) 100k TOTAL OUTPUT ERROR vs VIN POWER-SUPPLY REJECTION vs FREQUENCY 140 G=1 0 G = 10 G = 25 –1 –2 +125° 80 60 +25° –55° 40 20 0 0 10 20 30 0 40 Power-Supply Voltage (V) 4 10k 1k Frequency (Hz) 10 20 30 40 Power-Supply Voltage (V) INA170 www.ti.com SBOS193D TYPICAL CHARACTERISTICS (Cont.) + = 12V, R = 25kΩ, unless otherwise noted. At TA = +25°C, V+ = 5V, VIN L STEP RESPONSE STEP RESPONSE 1.5V 1V G = 100 G = 50 0.5V 0V 1V 2V G = 100 G = 10 0V 0V 20µs/div 10µs/div INA170 SBOS193D www.ti.com 5 OPERATION Figure 1 shows the basic circuit diagram for the INA170. Load current IS is drawn from supply VS through shunt resistor RS. The voltage drop in shunt resistor VS is forced across RG1 by the internal op-amp, causing current to flow into the collector of Q1. External resistor RL converts the output current to a voltage, VOUT, at the OUT pin. Without offset, the transfer function for the INA170 is: + – V–) IO = gm (VIN IN (1) where gm = 1000µA/V (2) + – V – ), is In the circuit of Figure 1, the input voltage, (VIN IN equal to IS • RS and the output voltage, VOUT, is equal to IO • RL. The transconductance, gm, of the INA170 is 1000µA/V. The complete transfer function for the current measurement amplifier in this application is: VOUT = (IS) (RS) (1000µA/V) (RL) (3) Applying a positive reference voltage to pin 3 causes a current to flow through ROS, forcing output current IO to be offset from zero. The transfer function then becomes:  V • R L   IS • RS • R L  VOUT =  REF ±  1kΩ  R OS   (4) The maximum differential input voltage for accurate measurements is 0.5V, which produces a 500µA output current. A differential input voltage of up to 2V will not cause damage. Differential measurements (pins 1 and 2) can be bipolar with a more-positive voltage applied to pin 2. If a more-negative voltage is applied to pin 1, output current IO will decrease towards zero. BASIC CONNECTION Figure 1 shows the basic connection of the INA170. The + and V – , should be connected as closely as input pins, VIN IN possible to the shunt resistor to minimize any resistance in series with the shunt resistance. The output resistor, RL, is shown connected between pin 6 and ground. Best accuracy is achieved with the output voltage measured directly across RL. This is especially important in high-current systems where load current could flow in the ground connections, affecting the measurement accuracy. No power-supply bypass capacitors are required for stability of the INA170. However, applications with noisy or high impedance power supplies may require de-coupling capacitors to reject power-supply noise. Connect bypass capacitors close to the device pins. POWER SUPPLIES The input circuitry of the INA170 can accurately measure beyond its power-supply voltage, V+. For example, the V+ power supply can be 5V, while the load power-supply voltage (INA170 input voltage) is up to +60V. However, the output-voltage range of the OUT terminal (pin 6) is limited by the supply. SELECTING RS AND RL The value chosen for the shunt resistor, RS, depends on the application and is a compromise between small-signal accuracy and maximum permissible voltage loss in the measurement line. High values of RS provide better accuracy at lower VP Load Power Supply +2.7 to 60V V+ power can be common or independent of load supply. Shunt RS + VIN IS – VIN 1 2 Load V+ INA170 RG1 1kΩ 2.7 ≤ (V+) ≤ 40V RG2 1kΩ 8 VOLTAGE GAIN EXACT RL (Ω) NEAREST 1% RL (Ω) 1 1k 1k 2 2k 2k 5 5k 4.99k 10 10k 10k 20 20k 20k 50 50k 49k 100 100k 100k VREF 3 Q2 5 Q1 4 ROS OUT 6 + I0 RL VO – FIGURE 1. Basic Circuit Connections. 6 INA170 www.ti.com SBOS193D currents by minimizing the effects of offset, while low values of RS minimize voltage loss in the supply line. For most applications, best performance is attained with an RS value that provides a full-scale shunt voltage of 50mV to 100mV. Maximum input voltage for accurate measurements is 500mV. RL is chosen to provide the desired full-scale output voltage. The output impedance of the INA170 Out terminal is very high which permits using values of RL up to 100kΩ with excellent accuracy. The input impedance of any additional circuitry at the output should be much higher than the value of RL to avoid degrading accuracy. output swing. The maximum output voltage compliance is limited by the lower of the two equations below: Vout + – V–) = (V+) – 0.7V – (VIN IN max (5) or Vout max – – 0.5V = VIN (6) (whichever is lower) BANDWIDTH Measurement bandwidth is affected by the value of the load resistor, RL. High gain produced by high values of RL will yield a narrower measurement bandwidth (see Typical Characteristic Curves). For widest possible bandwidth, keep the capacitive load on the output to a minimum. If bandwidth limiting (filtering) is desired, a capacitor can be added to the output, as shown in Figure 3. This will not cause instability. Some Analog-to-Digital (A/D) converters have input impedances that will significantly affect measurement gain. The input impedance of the A/D converter can be included as part of the effective RL if its input can be modeled as a resistor to ground. Alternatively, an op-amp can be used to buffer the A/D converter input, as shown in Figure 2. See Figure 1 for recommended values of RL. IS 2 1 1 2 f–3dB INA170 INA170 ZIN OPA340 6 4 1 f–3dB = 2πRLCL 6 4 RL VO RL CL Buffer of amp drives A/D converter without affecting gain. FIGURE 2. Buffering Output to Drive A/D Converter. FIGURE 3. Output Filter. OUTPUT VOLTAGE RANGE APPLICATIONS The INA170 is designed for current shunt measurement circuits as shown in Figure 1, but its basic function is useful in a wide range of circuitry. A creative engineer will find many unforeseen uses in measurement and level shifting circuits. The output of the INA170 is a current, which is converted to a voltage by the load resistor, RL. The output current remains accurate within the compliance voltage range of the output circuitry. The shunt voltage and the input common-mode and power supply voltages limit the maximum possible IS 1 2 Gain Set by RL INA170 VREF 6 3 5 4 ROS V0 Output Offset Current = VREF ROS Output Offset Voltage = VREF • RL ROS RL FIGURE 4. Offsetting the Output Voltage. INA170 SBOS193D www.ti.com 7 IS = ±10A 0.0125Ω +5V Load 28V 0.1µF ∆V = ±125mV Full-Scale 8 1 2 V+ – VIN IO = 125µA ± 125µA + VIN 6 INA170 IOS = 125µA OUT 3 +2.5V RL 10kΩ VREF ROS VOUT = 0 to +2.5V Full-Scale GND 5 4 20kΩ FIGURE 5. Bipolar Current Measurement. 8 INA170 www.ti.com SBOS193D PACKAGE OPTION ADDENDUM www.ti.com 14-Oct-2022 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) Samples (4/5) (6) INA170EA/250 ACTIVE VSSOP DGK 8 250 RoHS & Green NIPDAUAG Level-2-260C-1 YEAR -40 to 85 A70 Samples INA170EA/2K5 ACTIVE VSSOP DGK 8 2500 RoHS & Green NIPDAUAG Level-2-260C-1 YEAR -40 to 85 A70 Samples (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of