INA138-Q1, IN168-Q1 www.ti.com SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 HIGH-SIDE MEASUREMENT CURRENT SHUNT MONITOR Check for Samples: INA138-Q1, IN168-Q1 FEATURES 1 • • • • • • • • • Qualified For Automotive Applications ESD Protection Exceeds 2000 V Per MIL-STD-883, Method 3015; Exceeds 200 V Using Machine Model (C = 200 pF, R = 0) Complete Unipolar High-Side Current Measurement Circuit Wide Supply And Common-Mode Range – INA138: 2.7 V to 36 V – INA168: 2.7 V to 60 V Independent Supply and Input Common-Mode Voltages Single Resistor Gain Set Low Quiescent Current (25 µA typ) Wide Temperature Range: –40°C to +125°C TSSOP−8 and SOT23−5 Packages APPLICATIONS • • • • • Current Shunt Measurement Portable And Battery-Backup Systems Battery Chargers Power Management Precision Current Source DESCRIPTION The INA138 and INA168 are high-side, unipolar, current shunt monitors. Wide input common-mode voltage range, low quiescent current, and tiny TSSOP and SOT23 packaging enable uses in a variety of applications. Input common-mode and power-supply voltages are independent and can range from 2.7 V to 36 V for the INA138 and 2.7 V to 60 V for the INA168. Quiescent current is only 25 mA, which permits connecting the power supply to either side of the current measurement shunt with minimal error. The device converts a differential input voltage to a current output. This current is converted back to a voltage with an external load resistor that sets any gain from 1 to over 100. Although designed for current shunt measurement, the circuit invites creative applications in measurement and level shifting. Both the INA138 and INA168 are available in TSSOP−8 and SOT23−5 and are specified for the –40°C to +125°C temperature range. W W NC − No internal connection W 1 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. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2003–2010, Texas Instruments Incorporated INA138-Q1, IN168-Q1 SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 www.ti.com ORDERING INFORMATION (1) PRODUCT SPECIFIED TEMPERATURE RANGE PACKAGE DESIGNATOR (2) PACKAGE−LEAD PACKAGE MARKING TRANSPORT MEDIA, QUANTITY INA138QPWRQ1 TSSOP−8 PW −40°C to +125°C INA138 Tape and Reel, 2000 INA168QPWRQ1 TSSOP−8 PW −40°C to +125°C INA168 Tape and Reel, 2000 INA168QDBVRQ1 SOT23-5 DBV −40°C to +125°C LUIQ Tape and Reel, 3000 (1) (2) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. Package drawings, thermal data, and symbolization are available at www.ti.com/packaging. 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. ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) VALUE Supply voltage, V+ Analog inputs, VIN+, VIN− , Common mode INA138-Q1 −0.3 V to 60 V INA168-Q1 −0.3 V to 75 V INA138-Q1 −0.3 V to 60 V INA168-Q1 −0.3 V to 75 V Analog inputs, (VIN+) − (VIN−), Differential −40 V to 2 V Analog output, out −0.3 V to 40 V Operating temperature −55°C to 150°C Storage temperature −65°C to 150°C Junction temperature 150°C Thermal resistance, junction-to-ambient, RΘJA PW 150°C/W DBV 200°C/W Lead temperature (soldering, 10 seconds) (1) 260°C Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS TA = −40°C to 125°C, VS = 5 V, VIN+ = 12 V, and ROUT = 125 kΩ unless otherwise noted PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 100 500 mV Input Full-scale sense voltage VSENSE = VIN+ − VIN− Common-mode input range Common-mode rejection INA138 2.7 36 INA168 2.7 60 VIN+ = 2.7 V to 36 V, VSENSE = 50 mV INA138 VIN+ = 2.7 V to 60 V, VSENSE = 50 mV INA168 2 100 120 ±0.2 Offset voltage vs temperature (1) 120 dB Offset voltage (1) Offset voltage vs power supply, V+ 100 ±2 1 V+ = 2.7 V to 36 V, VSENSE = 50 mV INA138 V+ = 2.7 V to 60 V, VSENSE = 50 mV INA168 V mV mV/°C 0.1 10 0.1 10 mV/V Defined as the amount of input voltage, VSENSE, to drive the output to zero. Submit Documentation Feedback Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 INA138-Q1, IN168-Q1 www.ti.com SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 ELECTRICAL CHARACTERISTICS (continued) TA = −40°C to 125°C, VS = 5 V, VIN+ = 12 V, and ROUT = 125 kΩ unless otherwise noted PARAMETER Input bias current TEST CONDITIONS MIN TYP VIN+ = VIN− = 12 V MAX UNIT 10 mA Output Transconductance VSENSE = 10 mV − 150 mV Transconductance vs temperature VSENSE = 100 mV Nonlinearity error VSENSE = 10 mV to 150 mV Total output error VSENSE = 100 mV 194 206 10 Output impedance mA/V nA/°C ±0.01% ±0.2 % ±0.5 ±3.2 % 1 GΩ 5 pF Voltage output swing to power supply, V+ (V+) − 0.8 (V+) − 1.2 V Voltage output swing to common mode, VCM VCM − 0.5 VCM − 1.2 V Frequency Response Bandwidth Settling time (0.1%) ROUT = 5 kΩ 5 V step 800 ROUT = 125 kΩ 32 ROUT = 5 kΩ 1.8 ROUT = 125 kΩ 30 kHz ms Noise Output-current noise density TA = 25°C 9 pA/√Hz Total output-current noise BW = 100 kHz 3 nA RMS Power Supply Operating range, V+ Quiescent current INA138 2.7 36 INA168 2.7 60 VSENSE = 0, IO = 0 Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 25 60 Submit Documentation Feedback V mA 3 INA138-Q1, IN168-Q1 SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 www.ti.com TYPICAL CHARACTERISTICS TA = +25°C, V+ = 5 V, VIN+ = 12 V, and RL = 125 kΩ, unless otherwise noted. W Gain (dB) W W – Common-Mode Rejection (dB) COMMON-MODE REJECTION vs FREQUENCY – Figure 1. Figure 2. POWER-SUPPLY REJECTION vs FREQUENCY Total Output Error (%) Power-Supply Rejection (dB) – – – – – Figure 3. Figure 4. Quiescent Current (A) Total Output Error (%) TOTAL OUTPUT ERROR vs POWER-SUPPLY VOLTAGE – – Power-Supply Voltage (V) Power-Supply Voltage (V) Figure 5. 4 Submit Documentation Feedback Figure 6. Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 INA138-Q1, IN168-Q1 www.ti.com SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 TYPICAL CHARACTERISTICS (continued) TA = +25°C, V+ = 5 V, VIN+ = 12 V, and RL = 125 kΩ, unless otherwise noted. m m Figure 7. Figure 8. Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 Submit Documentation Feedback 5 INA138-Q1, IN168-Q1 SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 www.ti.com APPLICATION INFORMATION Figure 9 illustrates the basic circuit diagram for both the INA138 and INA168. 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. The transfer function for the INA138 is: IO = gm (VIN+ − VIN−) where gm = 200 mA/V. In the circuit of Figure 9, the input voltage, (VIN+ − VIN−), is equal to IS x RS and the output voltage, VOUT, is equal to IO x RL. The transconductance, gm, of the INA138 is 200 mA/V. The complete transfer function for the current measurement amplifier in this application is: VOUT = (IS) (RS) (200 mA/V) (RL) The maximum differential input voltage for accurate measurements is 0.5 V, which produces a 10 mA output current. A differential input voltage of up to 2 V will not cause damage. Differential measurements (pins 3 and 4) must be unipolar with a more-positive voltage applied to pin 3. If a more-negative voltage is applied to pin 3, the output current, IO, will be zero, but it will not cause damage. BASIC CONNECTION Figure 9 shows the basic connection of the INA138. The input pins, VIN+ and VIN−, should be connected as closely as possible to the shunt resistor to minimize any resistance in series with the shunt resistance. The output resistor, RL, is shown connected between pin 1 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 INA138. However, applications with noisy or high-impedance power supplies may require decoupling capacitors to reject power-supply noise. Connect bypass capacitors close to the device pins. POWER SUPPLIES The input circuitry of the INA138 can accurately measure beyond its power-supply voltage, V+. For example, the V+ power supply can be 5 V, whereas the load power supply voltage is up to +36 V (or +60 V with the INA168). The output voltage range of the OUT terminal, however, is limited by the lesser of the two voltages (see Output Voltage Range section). 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 currents by minimizing the effects of offset, while low values of RS minimize voltage loss in the supply line. For most applications, the best performance is attained with an RS value that provides a full-scale shunt voltage range of 50 mV to 100 mV. Maximum input voltage for accurate measurements is 500 mV. RL is chosen to provide the desired full-scale output voltage. The output impedance of the INA138 OUT terminal is very high which permits using values of RL up to 500 kΩ 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. Some analog-to-digital (A/D) converters have input impedances that significantly affects 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. Figure 9 shows the recommended values of RL. 6 Submit Documentation Feedback Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 INA138-Q1, IN168-Q1 www.ti.com SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 (A) – ≤ ≤ (A) W W – Figure 9. Basic Circuit Connections OUTPUT VOLTAGE RANGE The output of the INA138 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 output swing. The maximum output voltage compliance is limited by the lower of the two equations below: Vout max = (V+) − 0.7 V − (VIN+ − VIN−) or Vout max = VIN− − 0.5 V (whichever is lower) BANDWIDTH Measurement bandwidth is affected by the value of the load resistor, RL. High gain produced by high values of RL yields a narrower measurement bandwidth (see the Typical Characteristics section). For widest possible bandwidth, keep the capacitive load on the output to a minimum. Reduction in bandwidth due to capacitive load is shown in the Typical Characteristics section. If bandwidth limiting (filtering) is desired, a capacitor can be added to the output (see Figure 12). This will not cause instability. APPLICATIONS The INA138 is designed for current shunt measurement circuits, as shown in Figure 9, but its basic function is useful in a wide range of circuitry. An engineer may find many unforeseen uses in measurement and level shifting circuits. A few ideas are illustrated in Figure 10 through Figure 15. Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 Submit Documentation Feedback 7 INA138-Q1, IN168-Q1 SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 www.ti.com – – Figure 10. Buffering Output to Drive and A/D Converter p Figure 11. Output Filter m || m Figure 12. Offsetting the Output Voltage 8 Submit Documentation Feedback Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 INA138-Q1, IN168-Q1 www.ti.com SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 | W W W W W Figure 13. Bipolar Current Measurement Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 Submit Documentation Feedback 9 INA138-Q1, IN168-Q1 SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 www.ti.com 12-Bit W W Figure 14. Bipolar Current Measurement Using Differential Input of A/D Converter 10 Submit Documentation Feedback Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 INA138-Q1, IN168-Q1 www.ti.com SGLS174D – SEPTEMBER 2003 – REVISED DECEMBER 2010 12-Bit Figure 15. Multiplexed Measurement Using Logic Signal for Power Copyright © 2003–2010, Texas Instruments Incorporated Product Folder Link(s): INA138-Q1 IN168-Q1 Submit Documentation Feedback 11 PACKAGE OPTION ADDENDUM www.ti.com 12-Oct-2011 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Qty Eco Plan (2) Lead/ Ball Finish MSL Peak Temp (3) INA138QPWRQ1 ACTIVE TSSOP PW 8 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR INA168QDBVRQ1 ACTIVE SOT-23 DBV 5 3000 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR INA168QPWRG4Q1 ACTIVE TSSOP PW 8 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM INA168QPWRQ1 ACTIVE TSSOP PW 8 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Samples (Requires Login) (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) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. 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OTHER QUALIFIED VERSIONS OF INA138-Q1, INA168-Q1 : Addendum-Page 1 PACKAGE OPTION ADDENDUM www.ti.com 12-Oct-2011 • Catalog: INA138, INA168 NOTE: Qualified Version Definitions: • Catalog - TI's standard catalog product Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 1-Dec-2011 TAPE AND REEL INFORMATION *All dimensions are nominal Device INA168QDBVRQ1 Package Package Pins Type Drawing SPQ SOT-23 3000 DBV 5 Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 180.0 8.4 Pack Materials-Page 1 3.2 B0 (mm) K0 (mm) P1 (mm) 3.1 1.39 4.0 W Pin1 (mm) Quadrant 8.0 Q3 PACKAGE MATERIALS INFORMATION www.ti.com 1-Dec-2011 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) INA168QDBVRQ1 SOT-23 DBV 5 3000 210.0 185.0 35.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. 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