0
登录后你可以
  • 下载海量资料
  • 学习在线课程
  • 观看技术视频
  • 写文章/发帖/加入社区
创作中心
发布
  • 发文章

  • 发资料

  • 发帖

  • 提问

  • 发视频

创作活动
INA225AQDGKRQ1

INA225AQDGKRQ1

  • 厂商:

    BURR-BROWN(德州仪器)

  • 封装:

    VSSOP8

  • 描述:

    Current Monitor Regulator High-Side 8-VSSOP

  • 数据手册
  • 价格&库存
INA225AQDGKRQ1 数据手册
INA225-Q1 SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 INA225-Q1 AEC-Q100, 36-V, Bidirectional Current Sense Amplifier With Four PinSelectable Gain Settings 1 Features 3 Description • The INA225-Q1 is a voltage-output, current-sense amplifier that senses drops across current-sensing resistors at common-mode voltages that vary from 0 V to 36 V, independent of the supply voltage. The device is a bidirectional, current-shunt monitor that allows an external reference to be used to measure current flowing in both directions across a currentsensing resistor. • • • • • • • • • AEC-Q100 qualified: – Temperature grade 1: –40 °C to +125 °C – HBM ESD classification 2 – CDM ESD classification C4B Functional Safety-Capable – Documentation available to aid functional safety system design Wide common-mode range: 0 V to 36 V Offset voltage: ±150 μV (maximum, all gains) Offset voltage drift: 0.5 μV/°C (maximum) Gain accuracy, over temperature (maximum): – 25 V/V, 50 V/V: ±0.15% – 100 V/V: ±0.2% – 200 V/V: ±0.3% – 10-ppm/°C gain drift Bandwidth: 250 kHz (gain = 25 V/V) Programmable gains: – G1 = 25 V/V – G2 = 50 V/V – G3 = 100 V/V – G4 = 200 V/V Quiescent current: 350 μA (maximum) Package: 8-pin VSSOP 2 Applications • • • • • • Automotive lighting Body control module Motor control Valve control Cluster Central control module Four discrete gain levels are selectable using the two gain-select terminals (GS0 and GS1) to program gains of 25 V/V, 50 V/V, 100 V/V, and 200 V/V. The low-offset, zero-drift architecture and precision gain values enable current-sensing with maximum drops across the shunt as low as 10 mV of full-scale, while maintaining very high accuracy measurements over the entire operating temperature range. The device operates from a single +2.7-V to +36V power supply, drawing a maximum of 350 μA of supply current. The device is specified over the extended operating temperature range of –40 °C to +125 °C, and is offered in a VSSOP-8 package. Device Information(1) PART NUMBER PACKAGE INA225-Q1 (1) VSSOP (8) BODY SIZE (NOM) 3.00 mm x 3.00 mm For all available packages, see the package option addendum at the end of the data sheet. RSHUNT 5-V Supply Load CBYPASS 0.1µF VS INA225 IN- OUT ADC Microcontroller + IN+ GPIO REF GAIN SELECT GS0 GS0 GS1 GAIN GND GND VS VS GND VS GND VS 25 50 100 200 GS1 GND Typical Application An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 Table of Contents 1 Features............................................................................1 2 Applications..................................................................... 1 3 Description.......................................................................1 4 Revision History.............................................................. 2 5 Pin Configuration and Functions...................................3 6 Specifications.................................................................. 4 6.1 Absolute Maximum Ratings(1) .................................... 4 6.2 ESD Ratings............................................................... 4 6.3 Recommended Operating Conditions.........................4 6.4 Thermal Information....................................................4 6.5 Electrical Characteristics.............................................5 6.6 Typical Characteristics................................................ 7 7 Detailed Description......................................................13 7.1 Overview................................................................... 13 7.2 Functional Block Diagram......................................... 13 7.3 Feature Description...................................................13 7.4 Device Functional Modes..........................................16 8 Applications and Implementation................................ 19 8.1 Application Information............................................. 19 8.2 Typical Applications.................................................. 19 9 Power Supply Recommendations................................25 10 Layout...........................................................................25 10.1 Layout Guidelines................................................... 25 10.2 Layout Example...................................................... 25 11 Device and Documentation Support..........................26 11.1 Documentation Support.......................................... 26 11.2 Receiving Notification of Documentation Updates.. 26 11.3 Support Resources................................................. 26 11.4 Trademarks............................................................. 26 11.5 Electrostatic Discharge Caution.............................. 26 11.6 Glossary.................................................................. 26 12 Mechanical, Packaging, and Orderable Information.................................................................... 26 4 Revision History Changes from Revision * (February 2015) to Revision A (March 2021) Page • Updated the numbering format for tables, figures, and cross-references throughout the document..................1 • Added Functional Safety bullets to the Features ............................................................................................... 1 • Added title to key graphic................................................................................................................................... 1 • Added 25 kΩ value to RINT in Input Filtering ....................................................................................................16 2 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 5 Pin Configuration and Functions IN+ 1 8 IN- GND 2 7 REF VS 3 6 GS1 OUT 4 5 GS0 Figure 5-1. DGK Package VSSOP-8 (Top View) Table 5-1. Pin Functions PIN NO. NAME I/O DESCRIPTION 1 IN+ Analog input 2 GND Analog Connect to supply side of shunt resistor. Ground Power supply, 2.7 V to 36 V 3 VS Analog 4 OUT Analog output 5 GS0 Digital input Gain select. Connect to VS or GND. Table 7-3 lists terminal settings and the corresponding gain value. 6 GS1 Digital input Gain select. Connect to VS or GND. Table 7-3 lists terminal settings and the corresponding gain value. 7 REF Analog input Reference voltage, 0 V to VS 8 IN– Analog input Connect to load side of shunt resistor. Output voltage Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 3 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 6 Specifications 6.1 Absolute Maximum Ratings(1) Over operating free-air temperature range, unless otherwise noted. MIN Supply voltage UNIT +40 V –40 +40 V GND – 0.3 +40 V REF, GS0, and GS1 inputs GND – 0.3 (VS) + 0.3 V Output GND – 0.3 (VS) + 0.3 V –55 +150 °C +150 °C +150 °C Analog inputs, VIN+, VIN– (2) Differential (VIN+) – (VIN–) MAX Common-mode(3) Operating, TA Junction, TJ Temperature Storage, Tstg (1) (2) (3) –65 Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. VIN+ and VIN– are the voltages at the IN+ and IN– terminals, respectively. Input voltage at any terminal may exceed the voltage shown if the current at that terminal is limited to 5 mA. 6.2 ESD Ratings VALUE V(ESD) (1) Electrostatic discharge Human-body model (HBM), per AEC Q100-002(1) ±2500 Charged-device model (CDM), per AEC Q100-011 ±1000 UNIT V AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification. 6.3 Recommended Operating Conditions Over operating free-air temperature range, unless otherwise noted. MIN VCM Common-mode input voltage VS Operating supply voltage TA Operating free-air temperature NOM MAX UNIT 12 V 5 V –40 +125 °C 6.4 Thermal Information INA225-Q1 THERMAL METRIC(1) DGK (VSSOP) UNIT 8 PINS RθJA Junction-to-ambient thermal resistance 163.6 RθJC(top) Junction-to-case (top) thermal resistance 57.7 RθJB Junction-to-board thermal resistance 84.7 ψJT Junction-to-top characterization parameter 6.5 ψJB Junction-to-board characterization parameter 83.2 RθJC(bot) Junction-to-case (bottom) thermal resistance N/A (1) 4 °C/W For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953. Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 6.5 Electrical Characteristics At TA = +25 °C, VSENSE = VIN+ – VIN–, VS = +5 V, VIN+ = 12 V, and VREF = VS / 2, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNIT INPUT VCM CMR Common-mode input range TA = –40 °C to +125 °C Common-mode rejection VIN+ = 0 V to +36 V, VSENSE = 0 mV, TA = –40 °C to +125 °C RTI(1) 0 95 36 105 V dB VOS Offset voltage, VSENSE = 0 mV ±75 ±150 dVOS/dT RTI vs. temperature TA = –40 °C to +125 °C 0.2 0.5 μV/°C PSRR Power-supply rejection ratio VSENSE = 0 mV, VREF = 2.5 V, VS = 2.7 V to 36 V ±0.1 ±1 μV/V IB Input bias current VSENSE = 0 mV 72 85 μA IOS Input offset current VSENSE = 0 mV VREF Reference input range TA = –40 °C to +125 °C 55 ±0.5 0 μV μA VS V OUTPUT G EG Gain Gain error Gain error vs. temperature 25, 50, 100, 200 V/V Gain = 25 V/V and 50 V/V, VOUT = 0.5 V to VS – 0.5 V, TA = –40 °C to +125 °C ±0.05% ±0.15% Gain = 100 V/V, VOUT = 0.5 V to VS – 0.5 V, TA = –40 °C to +125 °C ±0.1% ±0.2% Gain = 200 V/V, VOUT = 0.5 V to VS – 0.5 V, TA = –40 °C to +125 °C ±0.1% ±0.3% G = 25 V/V, 50 V/V, 100 V/V, TA = –40 °C to +125 °C 3 10 G = 200 V/V, TA = –40 °C to +125 °C 5 15 Nonlinearity error VOUT = 0.5 V to VS – 0.5 V Maximum capacitive load No sustained oscillation ppm/°C ±0.01% 1 nF VOLTAGE OUTPUT(2) Swing to VS power-supply rail RL = 10 kΩ to GND, TA = –40 °C to +125 °C VS – 0.05 VS – 0.2 VREF = VS / 2, all gains, RL = 10 kΩ to GND, TA = –40 °C to +125 °C VGND + 5 VGND + 10 VREF = GND, gain = 25 V/V, RL = 10 kΩ to GND, TA = –40 °C to +125 °C VGND + 7 mV VREF = GND, gain = 50 V/V, RL = 10 kΩ to GND, TA = –40 °C to +125 °C VGND + 15 mV VREF = GND, gain = 100 V/V, RL = 10 kΩ to GND, TA = –40 °C to +125 °C VGND + 30 mV VREF = GND, gain = 200 V/V, RL = 10 kΩ to GND, TA = –40 °C to +125 °C VGND + 60 mV Gain = 25 V/V, CLOAD = 10 pF 250 kHz Gain = 50 V/V, CLOAD = 10 pF 200 kHz Gain = 100 V/V, CLOAD = 10 pF 125 kHz Swing to GND(3) V mV FREQUENCY RESPONSE BW Bandwidth SR Slew rate Gain = 200 V/V, CLOAD = 10 pF 70 kHz 0.4 V/μs 50 nV/√ Hz NOISE, RTI(1) Voltage noise density Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 5 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 At TA = +25 °C, VSENSE = VIN+ – VIN–, VS = +5 V, VIN+ = 12 V, and VREF = VS / 2, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNIT DIGITAL INPUT Ci Input capacitance Leakage input current 3 0 ≤ VIN ≤ VS 1 pF 2 μA VIL Low-level input logic level 0 0.6 V VIH High-level input logic level 2 VS V POWER SUPPLY VS Operating voltage range TA = –40 °C to +125 °C IQ Quiescent current VSENSE = 0 mV IQ over temperature TA = –40 °C to +125 °C +2.7 300 +36 V 350 μA 375 μA TEMPERATURE RANGE (1) (2) (3) 6 Specified range –40 +125 °C Operating range –55 +150 °C RTI = referred-to-input. See Typical Characteristic curve, Output Voltage Swing vs. Output Current (Figure 6-10). See Typical Characteristic curve, Unidirectional Output Voltage Swing vs. Temperature (Figure 6-14). Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 6.6 Typical Characteristics At TA = +25 °C, VS = +5 V, VIN+ = 12 V, and VREF = VS / 2, unless otherwise noted. 175 Poplulation Offset Voltage (µV) 150 125 100 75 50 200 175 150 125 75 100 50 0 25 -25 -50 -75 -100 -125 -150 -175 -200 25 0 ±50 Offset Voltage (µV) 0 ±25 25 Figure 6-1. Input Offset Voltage Production Distribution 50 75 100 125 150 Temperature (ƒC) C001 C002 Figure 6-2. Input Offset Voltage vs. Temperature 8 Population CMRR (µV/V) 7 6 5 4 20 18 16 14 12 8 10 6 4 2 0 -2 -4 -6 -8 -10 3 2 ±50 Common-Mode Rejection Ratio (µV/V) 0 ±25 25 75 100 125 150 C004 Gain Error (%) 0.1 0.08 0.06 0.04 0 0.02 -0.02 -0.04 -0.06 -0.1 -0.08 -0.12 -0.14 -0.16 -0.18 Population Figure 6-4. Common-Mode Rejection Ratio vs. Temperature -0.2 0.1 0.08 0.06 0.04 0.02 0 -0.02 -0.04 -0.06 -0.08 -0.1 -0.12 -0.14 -0.16 -0.18 -0.2 Population Figure 6-3. Common-Mode Rejection Production Distribution 50 Temperature (ƒC) C003 Gain Error (%) C005 Figure 6-5. Gain Error Production Distribution (Gain = 25 V/V) C006 Figure 6-6. Gain Error Production Distribution (Gain = 50 V/V) Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 7 INA225-Q1 www.ti.com Figure 6-7. Gain Error Production Distribution (Gain = 100 V/V) 0.5 0.3 Figure 6-8. Gain Error Production Distribution (Gain = 200 V/V) 50 45 40 0.2 0.1 Gain (dB) Gain Error (%) C008 25 V/V 50 V/V 100 V/V 200 V/V 0.4 0.0 -0.1 -0.2 35 30 25 200 V/V 100 V/V 50 V/V 25 V/V -0.3 20 -0.4 -0.5 15 ±50 0 ±25 25 50 75 100 125 Temperature (ƒC) 150 1 10 100 C009 VCM = 0 V 1k 10k Frequency (Hz) 100k 1M C010 VSENSE = 15 mVPP Figure 6-10. Gain vs. Frequency Figure 6-9. Gain Error vs. Temperature 140 120 120 100 100 80 CMR (dB) PSR (dB) 0.1 Gain Error (%) C007 80 60 60 40 40 20 20 0 0 10 100 1,000 10,000 Frequency (Hz) 100,000 1,000,000 10 Figure 6-11. Power-Supply Rejection Ratio vs. Frequency 100 1,000 10,000 Frequency (Hz) C011 VCM = 0 V VREF = 2.5 V VSENSE = 0 mV, Shorted VS = 5 V + 250-mV Sine Disturbance 8 0.08 0.06 0.04 0 0.02 -0.02 -0.04 -0.06 -0.1 Gain Error (%) -0.08 -0.12 -0.14 -0.16 -0.18 Population -0.2 0.1 0.08 0.06 0.04 0 0.02 -0.02 -0.04 -0.06 -0.1 -0.08 -0.12 -0.14 -0.16 -0.18 -0.2 Population SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 VS = 5 V VREF = 2.5 V VCM = 1-V Sine Wave 100,000 1,000,000 C012 VSENSE = 0 mV, Shorted Figure 6-12. Common-Mode Rejection Ratio vs. Frequency Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 100 Vs 90 Unidirectional, G = 200 80 Output Voltage (mV) Output Voltage Swing (V) (Vs) -1 (Vs) -2 (Vs) -3 GND +3 GND +2 - 40ƒC 25ƒC 125ƒC GND +1 GND 0 2 4 6 8 10 12 Current (mA) 14 16 18 70 Unidirectional, G = 100 60 50 Unidirectional, G = 50 40 Unidirectional, G = 25 30 Bidirectional, All Gains 20 10 20 0 C013 ±50 ±25 0 25 50 75 100 125 Temperature (ƒC) Unidirectional, REF = GND Figure 6-13. Output Voltage Swing vs Output Current Bidirectional, REF > GND 80 70 120 IB+, IB-, VREF = 0V Input Bias Current (µA) Input Bias Current (µA) C038 Figure 6-14. Unidirectional Output Voltage Swing vs. Temperature 140 100 80 60 IB+, IB-, VREF = 2.5V 40 20 60 50 40 30 IB+, IB-, VREF=0V 20 10 0 ±20 0 150 0 5 10 15 20 25 30 35 Common-Mode Voltage (V) ±10 0 40 5 10 Figure 6-15. Input Bias Current vs. Common-Mode Voltage (Supply Voltage = +5 V) 15 20 25 30 35 Common-Mode Voltage (V) C014 40 C015 Figure 6-16. Input Bias Current vs. Common-Mode Voltage (Supply Voltage = 0 V, Shutdown) 85 550 80 500 VS = 5V 450 VS = 2.7V Quiescent Current (µA) Input Bias Current (µA) VS = 36V 75 70 65 60 400 350 300 250 200 55 ±50 ±25 0 25 50 75 Temperature (ƒC) VS = 5 V 100 125 150 ±50 ±25 0 25 50 75 Temperature (ƒC) C016 100 125 150 C017 VCM = 12 V Figure 6-17. Input Bias Current vs. Temperature Figure 6-18. Quiescent Current vs. Temperature Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 9 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 100 400 Gain = 100 V/V 375 Input-Referred Voltage Noise (nV/¥+] Quiescent Current (µA) Gain = 200 V/V 350 325 300 275 200 V/V 250 100 V/V Gain = 50 V/V Gain = 25 V/V 50 V/V 225 25 V/V 200 0 10 5 10 15 20 25 30 35 Supply Voltage (V) 40 1 10 100 1k 10k Frequency (Hz) C018 VREF = 0 V VSENSE = 0 mV, Shorted Output (0.5 V/div) Referred-to-Input Voltage Noise (200 nV/div) Input (25 mV/div) Figure 6-20. Input-Referred Voltage Noise vs. Frequency Time (1 s/div) Time (25 µs/div) C020 VS = ± 2.5 V VCM = 0 V C021 VSENSE = 0 mV, Shorted Figure 6-21. 0.1-Hz to 10-Hz Voltage Noise (Referred-to-Input) Input (10 mV/div) Output (1 V/div) Output (1 V/div) Input (20 mV/div) Figure 6-22. Step Response (Gain = 25 V/V, 2-VPP Output Step) Time (25 µs/div) Time (25 µs/div) C022 Figure 6-23. Step Response (Gain = 50 V/V, 2-VPP Output Step) 10 1M C019 VS = ± 2.5 V Figure 6-19. Quiescent Current vs. Supply Voltage 100k C023 Figure 6-24. Step Response (Gain = 100 V/V, 2-VPP Output Step) Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com Output (1 V/div) Output (250 mV/div Input (5 mV/div) Gain Select (GS1) (2 V/div) SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 Time (25 µs/div) Time (5 µs/div) C024 C025 VDIFF = 20 mV VOUT at 50-V/V Gain = 1 V Figure 6-26. Gain Change Output Response (Gain = 25 V/V to 50 V/V) Output (1 V/div) Output (500 mV/div) Gain Select (GS0) (2 V/div) Gain Select (GS0) (2 V/div) Figure 6-25. Step Response (Gain = 200 V/V, 2-VPP Output Step) VOUT at 25-V/V Gain = 500 mV Time (5 µs/div) Time (5 µs/div) C026 VDIFF = 20 mV VOUT at 100-V/V Gain = 2 V VOUT at 25-V/V Gain = 500 mV VOUT at 50-V/V Gain = 1 V Figure 6-28. Gain Change Output Response (Gain = 50 V/V to 200 V/V) Output (1 V/div) Output (0.5 V/div) Gain Select (GS1) (2 V/div) Gain Select (GS1) (2 V/div) Figure 6-27. Gain Change Output Response (Gain = 25 V/V to 100 V/V) C027 VDIFF = 20 mV VOUT at 200-V/V Gain = 4 V Time (25 µs/div) Time (5 µs/div) C029 C028 VDIFF = 20 mV VOUT at 200-V/V Gain = 4 V VOUT at 100-V/V Gain = 2 V Figure 6-29. Gain Change Output Response (Gain = 100 V/V to 200 V/V) Figure 6-30. Gain Change Output Response From Saturation (Gain = 50 V/V to 25 V/V) Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 11 INA225-Q1 www.ti.com Gain Select (GS0) (2 V/div) Output (0.5 V/div) Output (0.5 V/div) Gain Select (GS0) (2 V/div) SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 Time (25 µs/div) Time (25 µs/div) C030 C031 Figure 6-32. Gain Change Output Response From Saturation (Gain = 200 V/V to 50 V/V) Common-Mode Voltage (10 V/div) Gain Select (GS1) (2 V/div) Figure 6-31. Gain Change Output Response From Saturation (Gain = 100 V/V to 25 V/V) Output (0.5 V/div ) Output (1 V/div) Gain = 25 V/V Gain = 100 V/V Gain = 200 V/V Gain = 50 V/V Time (25 µs/div) Time (5 µs/div) C032 C033 Figure 6-34. Common-Mode Voltage Transient Response Supply Voltage (2.5 V/div) Output (0.5 V/div) Figure 6-33. Gain Change Output Response From Saturation (Gain = 200 V/V to 100 V/V) Time (25 µs/div) C034 Figure 6-35. Start-Up Response 12 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 7 Detailed Description 7.1 Overview The INA225-Q1 is a 36-V, common-mode, zero-drift topology, current-sensing amplifier. This device features a significantly higher signal bandwidth than most comparable precision, current-sensing amplifiers, reaching up to 125 kHz at a gain of 100 V/V. A very useful feature present in the device is the built-in programmable gain selection. To increase design flexibility with the device, a programmable gain feature is added that allows changing device gain during operation in order to accurately monitor wider dynamic input signal ranges. Four discrete gain levels (25 V/V, 50 V/V, 100 V/V, and 200 V/V) are available in the device and are selected using the two gain-select terminals, GS0 and GS1. 7.2 Functional Block Diagram VS INA225 - IN- OUT + IN+ REF Gain Select GS0 GS1 GND 7.3 Feature Description 7.3.1 Selecting A Shunt Resistor The device measures the differential voltage developed across a resistor when current flows through it. This resistor is commonly referred to as a current-sensing resistor or a current-shunt resistor, with each term commonly used interchangeably. The flexible design of the device allows a wide range of input signals to be measured across this current-sensing resistor. Selecting the value of this current-sensing resistor is based primarily on two factors: the required accuracy of the current measurement and the allowable power dissipation across the resistor. The larger the voltage developed across this resistor the more accurate of a measurement that can be made because of the fixed internal amplifier errors. These fixed internal amplifier errors, which are dominated by the internal offset voltage of the device, result in a larger measurement uncertainty when the input signal gets smaller. When the input signal gets larger, the measurement uncertainty is reduced because the fixed errors become a smaller percentage of the signal being measured. A system design trade-off for improving the measurement accuracy through the use of the larger input signals is the increase in the power dissipated across the current-sensing resistor. Increasing the value of the currentshunt resistor increases the differential voltage developed across the resistor when current passes through it. However, the power that is then dissipated across this component also increases. Decreasing the value of Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 13 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 the current-shunt resistor value reduces the power dissipation requirements of the resistor, but increases the measurement errors resulting from the decreasing input signal. Finding the optimal value for the shunt resistor requires factoring both the accuracy requirement of the application and allowable power dissipation into the selection of the component. An increasing amount of very low ohmic value resistors are becoming available with values reaching down to 200 μΩ with power dissipations of up to 5 W, thus enabling very large currents to be accurately monitored using sensing resistors. The maximum value for the current-sensing resistor that can be chosen is based on the full-scale current to be measured, the full-scale input range of the circuitry following the device, and the device gain selected. The minimum value for the current-sensing resistor is typically a design-based decision because maximizing the input range of the circuitry following the device is commonly preferred. Full-scale output signals that are significantly less than the full input range of the circuitry following the device output can limit the ability of the system to exercise the full dynamic range of system control based on the current measurement. 7.3.1.1 Selecting A Current-Sense Resistor Example The example in Table 7-1 is based on a set of application characteristics, including a 10-A full-scale current range and a 4-V full-scale output requirement. The calculations for selecting a current-sensing resistor of an appropriate value are shown in Table 7-1. Table 7-1. Calculating the Current-Sense Resistor, RSENSE PARAMETER IMAX Full-scale current VOUT Full-scale output voltage EQUATION RESULT 10 A 4V Gain Gain selected VDIFF Ideal maximum differential input voltage RSHUNT Shunt resistor value PRSENSE Current-sense resistor power dissipation VOS Error Offset voltage error Initial selection based on default gain setting. 25 V/V VDiff = VOUT / Gain 160 mV RSHUNT = VDiff / IMAX 16 mΩ RSENSE x IMAX 2 1.6 W (VOS / VDIFF ) x 100 0.094% 7.3.1.2 Optimizing Power Dissipation versus Measurement Accuracy The example shown in Table 7-1 results in a maximum current-sensing resistor value of 16 mΩ to develop the 160 mV required to achieve the 4-V full-scale output with the gain set to 25 V/V. The power dissipated across this 16-mΩ resistor at the 10-A current level is 1.6 W, which is a fairly high power dissipation for this component. Adjusting the device gain allows alternate current-sense resistor values to be selected to ease the power dissipation requirement of this component. 14 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 Changing the gain setting from 25 V/V to 100 V/V, as shown in Table 7-2, decreases the maximum differential input voltage from 160 mV down to 40 mV, thus requiring only a 4-mΩ current-sensing resistor to achieve the 4-V output at the 10-A current level. The power dissipated across this resistor at the 10-A current level is 400 mW, significantly increasing the availability of component options to select from. The increase in gain by a factor of four reduces the power dissipation requirement of the current-sensing resistor by this same factor of four. However, with this smaller full-scale signal, the measurement uncertainty resulting from the device fixed input offset voltage increases by the same factor of four. The measurement error resulting from the device input offset voltage is approximately 0.1% at the 160-mV full-scale input signal for the 25-V/V gain setting. Increasing the gain to 100 V/V and decreasing the full-scale input signal to 40 mV increases the offset induced measurement error to 0.38%. Table 7-2. Accuracy and RSENSE Power Dissipation vs. Gain Setting PARAMETER EQUATION IMAX Full-scale current VOUT Full-scale output voltage Gain Gain selected VDIFF Ideal maximum differential input voltage RSENSE Current-sense resistor value RESULT 10 A 4V 100 V/V PRSENSE Current-sense resistor power dissipation VOS Error Offset voltage error VDiff = VOUT / Gain 40 mV RSENSE = VDiff / IMAX 4 mΩ RSENSE x IMAX 2 0.4 W (VOS / VDIFF ) x 100 0.375% 7.3.2 Programmable Gain Select The device features a terminal-controlled gain selection in determining the device gain setting. Four discrete gain options are available (25 V/V, 50 V/V, 100 V/V, and 200 V/V) on the device and are selected based on the voltage levels applied to the gain-select terminals (GS0 and GS1). These terminals are typically fixed settings for most applications but the programmable gain feature can be used to adjust the gain setting to enable wider dynamic input range monitoring as well as to create an automatic gain control (AGC) network. Table 7-3 shows the corresponding gain values and gain-select terminal values for the device. Table 7-3. Gain Select Settings GAIN GS0 GS1 25 V/V GND GND 50 V/V GND VS 100 V/V VS GND 200 V/V VS VS Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 15 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 7.4 Device Functional Modes 7.4.1 Input Filtering An obvious and straightforward location for filtering is at the device output; however, this location negates the advantage of the low output impedance of the internal buffer. The input then represents the best location for implementing external filtering. Figure 7-1 shows the typical implementation of the input filter for the device. RSHUNT 5-V Supply Power Supply Load RS ” 10 CBYPASS 0.1 µF RS ” 10 VS Device ¦-3dB = 1 CF 2ŒRSCF RINT ¦-3dB OUT BIAS Output + RINT REF GS0 GS1 GND Figure 7-1. Input Filter Care must be taken in the selection of the external filter component values because these components can affect device measurement accuracy. Placing external resistance in series with the input terminals creates an additional error so these resistors should be kept as low of a value as possible with a recommended maximum value of 10 Ω or less. Increasing the value of the input filter resistance beyond 10 Ω results in a smaller voltage signal present at the device input terminals than what is developed across the current-sense shunt resistor. The internal bias network shown in Figure 7-1 creates a mismatch in the two input bias current paths when a differential voltage is applied between the input terminals. Under normal conditions, where no external resistance is added to the input paths, this mismatch of input bias currents has little effect on device operation or accuracy. However, when additional external resistance is added (such as for input filtering), the mismatch of input bias currents creates unequal voltage drops across these external components. The mismatched voltages result in a signal reaching the input terminals that is lower in value than the signal developed directly across the current-sensing resistor. The amount of variance in the differential voltage present at the device input relative to the voltage developed at the shunt resistor is based both on the external series resistance value (RS) and the internal input resistors (RINT = 25 kΩ). The reduction of the shunt voltage reaching the device input terminals appears as a gain error when comparing the output voltage relative to the voltage across the shunt resistor. A factor can be calculated to determine the amount of gain error that is introduced by the addition of external series resistance. 16 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 The amount of error these external filter resistors introduce into the measurement can be calculated using the simplified gain error factor in Equation 1, where the gain error factor is calculated with Equation 2. Gain Error Factor = 50,000 (41 x RS) + 50,000 (1) (1250 ´ RINT) Gain Error Factor = (1250 ´ RS) + (1250 ´ RINT) + (RS ´ RINT) (2) where: • • RINT is the internal input impedance, and RS is the external series resistance. For example, using the gain error factor (Equation 1), a 10-Ω series resistance results in a gain error factor of 0.992. The corresponding gain error is then calculated using Equation 3, resulting in a gain error of approximately 0.81% solely because of the external 10-Ω series resistors. Using 100-Ω filter resistors increases this gain error to approximately 7.58% from these resistors alone. Gain Error (%) = 1 ± Gain Error Factor (3) 7.4.2 Shutting Down the Device Although the device does not have a shutdown terminal, the low-power consumption allows for the device to be powered from the output of a logic gate or transistor switch that can turn on and turn off the voltage connected to the device power-supply terminal. However, in current-shunt monitoring applications, there is also a concern for how much current is drained from the shunt circuit in shutdown conditions. Evaluating this current drain involves considering the device simplified schematic in shutdown mode, as shown in Figure 7-2. CBYPASS 0.1 µF Supply Shutdown Control Load VS Device IN- OUT Output Reference Voltage + IN+ GS0 GS1 + REF - GND Figure 7-2. Shutting Down the Device Note that there is typically a 525-kΩ impedance (from the combination of the 500-kΩ feedback and 25-kΩ input resistors) from each device input to the REF terminal. The amount of current flowing through these terminals depends on the respective configuration. For example, if the REF terminal is grounded, calculating the effect Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 17 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 of the 525-kΩ impedance from the shunt to ground is straightforward. However, if the reference or op amp is powered while the device is shut down, the calculation is direct. Instead of assuming 525 kΩ to ground, assume 525 kΩ to the reference voltage. If the reference or op amp is also shut down, some knowledge of the reference or op amp output impedance under shutdown conditions is required. For instance, if the reference source behaves similar to an open circuit when un-powered, little or no current flows through the 525-kΩ path. 7.4.3 Using the Device with Common-Mode Transients Above 36 V With a small amount of additional circuitry, the device can be used in circuits subject to transients higher than 36 V (such as automotive applications). Use only zener diodes or zener-type transient absorbers (sometimes referred to as transzorbs); any other type of transient absorber has an unacceptable time delay. Start by adding a pair of resistors, as shown in Figure 7-3, as a working impedance for the zener. Keeping these resistors as small as possible is preferable, most often around 10 Ω. This value limits the impact on accuracy with the addition of these external components, as described in the Input Filtering section. Larger values can be used if necessary with the result having an impact on gain error. Because this circuit limits only short-term transients, many applications are satisfied with a 10-Ω resistor along with conventional zener diodes of the lowest power rating available. This combination uses the least amount of board space. These diodes can be found in packages as small as SOT-523 or SOD-523. RSHUNT Power Supply 5-V Supply Load CBYPASS 0.1µF RPROTECT ” 10 VS Device IN- OUT Output + IN+ REF GS0 GS1 GND Figure 7-3. Device Transient Protection 18 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 8 Applications and Implementation Note Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes, as well as validating and testing their design implementation to confirm system functionality. 8.1 Application Information The INA225-Q1 measures the voltage developed across a current-sensing resistor when current passes through it. The ability to drive the reference terminal to adjust the functionality of the output signal offers multiple configurations discussed throughout this section. 8.2 Typical Applications 8.2.1 Microcontroller-Configured Gain Selection RSHUNT Power Supply 5-V Supply Load CBYPASS 0.1 µF VS Device IN- OUT + ADC Microcontroller IN+ GPIO REF GS0 GS1 GND Figure 8-1. Microcontroller-Configured Gain Selection Schematic 8.2.1.1 Design Requirements Figure 8-1 shows the typical implementation of the device interfacing with an analog-to-digital converter (ADC) and microcontroller. 8.2.1.2 Detailed Design Procedure In this application, the device gain setting is selected and controlled by the microcontroller to ensure the device output is within the linear input range of the ADC. Because the output range of the device under a specific gain setting approaches the linear output range of the INA225-Q1 itself or the linear input range of the ADC, the microcontroller can adjust the device gain setting to ensure the signal remains within both the device and the ADC linear signal range. Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 19 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 8.2.1.3 Application Curve Figure 8-2 illustrates how the microcontroller can monitor the ADC measurements to determine if the device gain setting should be adjusted to ensure the output of the device remains within the linear output range as well as the linear input range of the ADC. When the output of the device rises to a level near the desired maximum voltage level, the microcontroller can change the GPIO settings connected to the G0 and G1 gain-select terminals to adjust the device gain setting, thus resulting in the output voltage dropping to a lower output range. When the input current increases, the output voltage increases again to the desired maximum voltage level. The microcontroller can again change the device gain setting to drop the output voltage back to a lower range. Output Voltage 200 Gain (V/V) 5 Gain 4 150 3 100 2 50 1 Output Voltage (V) 250 0 0 0 1 2 3 4 5 6 7 8 Load Current (A) 9 10 C035 Figure 8-2. Microcontroller-Configured Gain Selection Response 20 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 8.2.2 Unidirectional Operation Supply 2.7-V to 36-V Supply Load CBYPASS 0.1 µF VS Device IN- OUT Output + IN+ REF VS GS0 GS1 GND Figure 8-3. Unidirectional Application Schematic 8.2.2.1 Design Requirements The device can be configured to monitor current flowing in one direction or in both directions, depending on how the REF terminal is configured. For measuring current in one direction, only the REF terminal is typically connected to ground as shown in Figure 8-3. With the REF terminal connected to ground, the output is low with no differential input signal applied. When the input signal increases, the output voltage at the OUT terminal increases above ground based on the device gain setting. Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 21 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 8.2.2.2 Detailed Design Procedure The linear range of the output stage is limited in how close the output voltage can approach ground under zero input conditions. Resulting from an internal node limitation when the REF terminal is grounded (unidirectional configuration) the device gain setting determines how close to ground the device output voltage can achieve when no signal is applied; see Figure 6-14. To overcome this internal node limitation, a small reference voltage (approximately 10 mV) can be applied to the REF terminal to bias the output voltage above this voltage level. The device output swing capability returns to the 10-mV saturation level with this small reference voltage present. At the lowest gain setting, 25 V/V, the device is capable of accurately measuring input signals that result in output voltages below this 10-mV saturation level of the output stage. For these gain settings, a reference voltage can be applied to bias the output voltage above this lower saturation level to allow the device to monitor these smaller input signals. To avoid common-mode rejection errors, buffer the reference voltage connected to the REF terminal. A less frequently-used output biasing method is to connect the REF terminal to the supply voltage, VS. This method results in the output voltage saturating at 200 mV below the supply voltage when no differential input signal is present. This method is similar to the output saturated low condition with no input signal when the REF terminal is connected to ground. The output voltage in this configuration only responds to negative currents that develop negative differential input voltage relative to the device IN– terminal. Under these conditions, when the differential input signal increases negatively, the output voltage moves downward from the saturated supply voltage. The voltage applied to the REF terminal must not exceed the device supply voltage. 8.2.2.3 Application Curve Output Voltage (0.5 V/div) An example output response of a unidirectional configuration is shown in Figure 8-4. With the REF terminal connected directly to ground, the output voltage is biased to this zero output level. The output rises above the reference voltage for positive differential input signals but cannot fall below the reference voltage for negative differential input signals because of the grounded reference voltage. 0V Output Vref Time (500 µs/div) C036 Figure 8-4. Unidirectional Application Output Response 22 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 8.2.3 Bidirectional Operation Supply 2.7-V to 36-V Supply Load CBYPASS 0.1µF VS Device IN- OUT Output Reference Voltage + IN+ + VS GS0 GS1 - - REF GND Figure 8-5. Bidirectional Application Schematic 8.2.3.1 Design Requirements The device is a bidirectional, current-sense amplifier capable of measuring currents through a resistive shunt in two directions. This bidirectional monitoring is common in applications that include charging and discharging operations where the current flow-through resistor can change directions. 8.2.3.2 Detailed Design Procedure The ability to measure this current flowing in both directions is enabled by applying a voltage to the REF terminal, as shown in Figure 8-5. The voltage applied to REF (VREF) sets the output state that corresponds to the zero-input level state. The output then responds by increasing above VREF for positive differential signals (relative to the IN– terminal) and responds by decreasing below VREF for negative differential signals. This reference voltage applied to the REF terminal can be set anywhere between 0 V to VS. For bidirectional applications, VREF is typically set at mid-scale for equal range in both directions. In some cases, however, VREF is set at a voltage other than half-scale when the bidirectional current is non-symmetrical. Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 23 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 8.2.3.3 Application Curve Output Voltage (0.5 V/div) An example output response of a bidirectional configuration is shown in Figure 8-6. With the REF terminal connected to a reference voltage, 2.5 V in this case, the output voltage is biased upwards by this reference level. The output rises above the reference voltage for positive differential input signals and falls below the reference voltage for negative differential input signals. Output 0V Vref Time (500 µs/div) C037 Figure 8-6. Bidirectional Application Output Response 24 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 9 Power Supply Recommendations The input circuitry of the device can accurately measure signals on common-mode voltages beyond its power supply voltage, VS. For example, the voltage applied to the VS power supply terminal can be 5 V, whereas the load power-supply voltage being monitored (the common-mode voltage) can be as high as +36 V. Note also that the device can withstand the full –0.3-V to +36-V range at the input terminals, regardless of whether the device has power applied or not. Power-supply bypass capacitors are required for stability and should be placed as closely as possible to the supply and ground terminals of the device. A typical value for this supply bypass capacitor is 0.1 μF. Applications with noisy or high-impedance power supplies may require additional decoupling capacitors to reject power-supply noise. 10 Layout 10.1 Layout Guidelines • • Connect the input terminals to the sensing resistor using a Kelvin or 4-wire connection. This connection technique ensures that only the current-sensing resistor impedance is detected between the input terminals. Poor routing of the current-sensing resistor commonly results in additional resistance present between the input terminals. Given the very low ohmic value of the current resistor, any additional high-current carrying impedance can cause significant measurement errors. The power-supply bypass capacitor should be placed as closely as possible to the supply and ground terminals. The recommended value of this bypass capacitor is 0.1 μF. Additional decoupling capacitance can be added to compensate for noisy or high-impedance power supplies. 10.2 Layout Example VIA to Power or Ground Plane VIA to Ground Plane Supply Bypass Capacitor Supply Voltage Output Signal Trace IN+ IN- GND REF VS GS1 OUT GS0 Figure 10-1. Recommended Layout Note The layout shown has REF connected to ground for unidirectional operation. Gain-select terminals (GS0 and GS1) are also connected to ground, indicating a 25-V/V gain setting. Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 25 INA225-Q1 www.ti.com SBOS728A – FEBRUARY 2015 – REVISED MARCH 2021 11 Device and Documentation Support 11.1 Documentation Support 11.1.1 Related Documentation For related documentation see the following: • INA225EVM User's Guide, SBOU140 11.2 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on Subscribe to updates to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 11.3 Support Resources TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight from the experts. Search existing answers or ask your own question to get the quick design help you need. Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. 11.4 Trademarks TI E2E™ is a trademark of Texas Instruments. All trademarks are the property of their respective owners. 11.5 Electrostatic Discharge Caution 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. 11.6 Glossary TI Glossary This glossary lists and explains terms, acronyms, and definitions. 12 Mechanical, Packaging, and Orderable Information The following pages include mechanical packaging and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. 26 Submit Document Feedback Copyright © 2022 Texas Instruments Incorporated Product Folder Links: INA225-Q1 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 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) (4/5) (6) INA225AQDGKRQ1 ACTIVE VSSOP DGK 8 2500 RoHS & Green NIPDAUAG Level-2-260C-1 YEAR -40 to 125 IAAQ (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
INA225AQDGKRQ1 价格&库存

很抱歉,暂时无法提供与“INA225AQDGKRQ1”相匹配的价格&库存,您可以联系我们找货

免费人工找货