INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 High or Low Side, Bi-Directional CURRENT/POWER MONITOR with Two-Wire Interface FEATURES DESCRIPTION 1 • • • • • 2 • • • HIGH- or LOW-SIDE SENSING SENSES BUS VOLTAGES FROM 0V TO +26V REPORTS CURRENT, VOLTAGE, AND POWER 16 PROGRAMMABLE ADDRESSES HIGH ACCURACY: 1% (Max) OVER TEMPERATURE USER PROGRAMMABLE CALIBRATION FAST (3.4MHz) TWO-WIRE MODE MSOP-10 PACKAGE APPLICATIONS • • • • • • • • SERVERS TELECOM EQUIPMENT NOTEBOOK COMPUTERS POWER MANAGEMENT BATTERY CHARGERS AUTOMOTIVE POWER SUPPLIES TEST EQUIPMENT The INA220 is a current shunt and power monitor with an Two-Wire interface. The INA220 monitors both shunt drop and supply voltage. A programmable calibration value, combined with an internal multiplier, enables direct readouts in amperes. An additional multiplying register calculates power in watts. The Two-Wire interface features 16 programmable addresses. The separate shunt input on the INA220 allows it to be used in systems with low-side sensing. The INA220 senses across shunts on buses that can vary from 0V to 26V, useful for low-side sensing or CPU power supplies. The device uses a single +3V to +5.5V supply, drawing a maximum of 1mA of supply current. The INA220 operates from –40°C to +125°C. RELATED PRODUCTS DESCRIPTION DEVICE Current/Power Monitor with Watchdog, Peak-Hold, and Fast Comparator Functions INA209 Zerø-Drift, Low-Cost, Analog Current Shunt Monitor Series in Small Package Zerø-Drift, Bi-Directional Current Power Monitor with Two-Wire Interface Supply (0 to 26V) CBYPASS 0.1mF HighSide Shunt INA210–INA214 INA219 +3.3V to +5V Bus Voltage Input VS (Supply Voltage) INA220 Load ´ SDA Power Register SCL LowSide Shunt R2F V VIN+ Current Register Two-Wire Interface ADC R1F CF DATA CLK A0 A1 Voltage Register VIN- I GND General Load, Low- or High-Side Sensing 1 2 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. 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 © 2009, Texas Instruments Incorporated INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com 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. PACKAGING INFORMATION (1) (1) PRODUCT PACKAGE-LEAD PACKAGE DESIGNATOR PACKAGE MARKING INA220 MSOP-10 DGS OOUI 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. ABSOLUTE MAXIMUM RATINGS (1) Over operating free-air temperature range (unless otherwise noted). Supply Voltage, VS UNIT 6 V –26 to +26 V –0.3 to +26 V VBUS –0.3 to +26 V SDA GND – 0.3 to +6 V SCL Analog Inputs, VIN+, VIN– Differential (VIN+) – (VIN–) (2) INA220 Common-Mode GND – 0.3 to VS + 0.3 V Input Current Into Any Pin 5 mA Open-Drain Digital Output Current 10 mA Operating Temperature –40 to +125 °C Storage Temperature –65 to +150 °C Junction Temperature +150 °C Human Body Model (HBM) 4000 V Charged-Device Model (CDM) 1000 V Machine Model (MM) 150 V ESD Ratings (1) (2) 2 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. VIN+ and VIN– may have a differential voltage of –26V to +26V; however, the voltage at these pins must not exceed the range –0.3V to +26V. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 ELECTRICAL CHARACTERISTICS: VS = +3.3V Boldface limits apply over the specified temperature range, TA = –25°C to +85°C. At TA = +25°C, VIN+ = 12V, VSENSE = (VIN+ – VIN–) = 32mV, VBUS = 12V, PGA = ÷ 1, and BRNG (1) = 1, unless otherwise noted. INA220 PARAMETER TEST CONDITIONS MIN PGA = ÷ 1 0 PGA = ÷ 2 PGA = ÷ 4 TYP MAX UNIT ±40 mV 0 ±80 mV 0 ±160 mV PGA = ÷ 8 0 ±320 mV BRNG = 1 0 32 V BRNG = 0 0 16 VIN+ = 0V to 26V 100 INPUT Full-Scale Current Sense (Input) Voltage Range Bus Voltage (Input Voltage) Range (2) Common-Mode Rejection Offset Voltage, RTI (3) CMRR VOS PSRR V dB PGA = ÷ 1 ±10 ±100 µV PGA = ÷ 2 ±20 ±125 µV PGA = ÷ 4 ±30 ±150 µV PGA = ÷ 8 ±40 ±200 vs Temperature vs Power Supply 120 VS = 3V to 5.5V Current Sense Gain Error µV 0.1 µV/°C 10 µV/V ±40 m% 10 ppm/°C VIN+ Pin 20 µA VIN– Pin 20 µA VBUS Pin (4) 320 kΩ vs Temperature Input Impedance Input Leakage (5) Active Mode Power-Down Mode VIN+ Pin 0.1 ±0.5 µA VIN– Pin 0.1 ±0.5 µA DC ACCURACY ADC Basic Resolution 12 Bits 1LSB Step Size Shunt Voltage 10 µV Bus Voltage 4 mV Current Measurement Error ±0.2 over Temperature Bus Voltage Measurement Error VBUS = 12V ±0.2 over Temperature ±0.5 % ±1 % ±0.5 % ±1 Differential Nonlinearity ±0.1 % LSB ADC TIMING ADC Conversion Time 12-Bit 532 586 µs 11-Bit 276 304 µs 10-Bit 148 163 µs 9-Bit 84 93 µs Minimum Convert Input Low Time µs 4 SMBus SMBus Timeout (6) (1) (2) (3) (4) (5) (6) 28 35 ms BRNG is bit 13 of the Configuration Register. This parameter only expresses the full-scale range of the ADC scaling. In no event should more than 26V be applied to this device. Referred-to-input (RTI). The input impedance of this pin may vary approximately ±15%. Input leakage is positive (current flowing into the pin) for the conditions shown at the top of the table. Negative leakage currents can occur under different input conditions. SMBus timeout in the INA220 resets the interface any time SCL or SDA is low for over 28ms. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 3 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com ELECTRICAL CHARACTERISTICS: VS = +3.3V (continued) Boldface limits apply over the specified temperature range, TA = –25°C to +85°C. At TA = +25°C, VIN+ = 12V, VSENSE = (VIN+ – VIN–) = 32mV, VBUS = 12V, PGA = ÷ 1, and BRNG = 1, unless otherwise noted. INA220 PARAMETER TEST CONDITIONS MIN TYP MAX UNIT DIGITAL INPUTS (SDA as Input, SCL, A0, A1) Input Capacitance 3 0 ≤ VIN ≤ VS Leakage Input Current 0.1 pF 1 µA V Input Logic Levels: VIH 0.7 (VS) 6 VIL –0.3 0.3 (VS) Hysteresis 500 V mV OPEN-DRAIN DIGITAL OUTPUTS (SDA) Logic '0' Output Level High-Level Output Leakage Current ISINK = 3mA 0.15 0.4 V VOUT = VS 0.1 1 µA POWER SUPPLY Operating Supply Range +3 +5.5 V 0.7 1 mA Quiescent Current, Power-Down Mode 6 15 µA Power-On Reset Threshold 2 Quiescent Current V TEMPERATURE RANGE Specified Temperature Range –25 +85 °C Operating Temperature Range –40 +125 °C Thermal Resistance (7) θJA MSOP-10 (7) 4 200 °C/W θJA value is based on JEDEC low-K board. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 PIN CONFIGURATION DGS PACKAGE MSOP-10 (Top View) A1 1 10 VIN+ A0 2 9 VIN- NC 3 8 VBUS SDA 4 7 GND SCL 5 6 VS PIN DESCRIPTIONS MSOP-10 (DGS) PIN NO NAME DESCRIPTION 1 A1 Address pin. Connect to GND, SCL, SDA, or VS. Table 1 shows pin settings and corresponding addresses. 2 A0 Address pin. Connect to GND, SCL, SDA, or VS. Table 1 shows pin settings and corresponding addresses. 3 NC No internal connection 4 SDA Serial bus data line. 5 SCL Serial bus clock line. 6 VS 7 GND Power supply, 3V to 5.5V. Ground. 8 VBUS Bus voltage input. 9 VIN– Negative differential shunt voltage. Connect to negative side of shunt resistor. Bus voltage is measured from this pin to ground. 10 VIN+ Positive differential shunt voltage. Connect to positive side of shunt resistor. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 5 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com TYPICAL CHARACTERISTICS At TA = +25°C, VIN+ = 12V, VSENSE = (VIN+ – VIN–) = 32mV, PGA = ÷ 1, and BRNG = 1, unless otherwise noted. ADC SHUNT OFFSET vs TEMPERATURE 100 -10 80 -20 60 -30 40 Offset (mV) Gain (dB) FREQUENCY RESPONSE 0 -40 -50 -60 20 0 -20 -70 -40 -80 -60 -90 -80 -100 -100 1k 100 10 10k 100k 320mV Range 160mV Range 1M 80mV Range -50 80 45 60 40 40 35 160mV Range -20 30 25 20 10 5 -80 0 -100 -50 -25 0 25 50 75 100 125 -50 -25 0 Figure 3. 50 75 100 125 Figure 4. ADC BUS GAIN ERROR vs TEMPERATURE INTEGRAL NONLINEARITY vs INPUT VOLTAGE 100 20 80 15 60 10 40 16V 20 INL (mV) Gain Error (m%) 25 Temperature (°C) Temperature (°C) 0 -20 5 0 -5 32V -40 -10 -60 -15 -80 -100 -50 -25 0 25 50 75 100 125 -20 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 Input Voltage (V) Temperature (°C) Figure 5. 6 16V Range 32V Range 15 80mV Range 40mV Range -60 125 100 ADC BUS VOLTAGE OFFSET vs TEMPERATURE 50 Offset (mV) Gain Error (m%) ADC SHUNT GAIN ERROR vs TEMPERATURE -40 75 Figure 2. 100 320mV Range 50 Temperature (°C) Figure 1. 0 25 0 -25 Input Frequency (Hz) 20 40mV Range Figure 6. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VIN+ = 12V, VSENSE = (VIN+ – VIN–) = 32mV, PGA = ÷ 1, and BRNG = 1, unless otherwise noted. INPUT CURRENTS WITH LARGE DIFFERENTIAL VOLTAGES (VIN+ at 12V, Sweep of VIN–) 2.0 ACTIVE IQ vs TEMPERATURE 1.2 VS+ = 5V 1.0 1.0 VS = 5V 0.8 0.5 IQ (mA) Input Currents (mA) 1.5 VS+ = 3V 0 VS+ = 3V 0.6 VS = 3V 0.4 -0.5 0.2 -1.0 VS+ = 5V 0 -1.5 10 5 0 15 20 25 30 -50 0 25 50 Temperature (°C) Figure 7. Figure 8. SHUTDOWN IQ vs TEMPERATURE 75 1.0 14 0.9 125 VS = 5V 0.8 0.7 IQ (mA) 10 VS = 5V 8 6 VS = 3V 4 0.6 VS = 3V 0.5 0.4 0.3 0.2 2 0.1 0 0 -50 25 0 -25 50 75 100 1k 125 10k 100k Temperature (°C) SCL Frequency (Hz) Figure 9. Figure 10. TOTAL PERCENT BUS VOLTAGE ERROR vs SUPPLY VOLTAGE 1M 10M SHUTDOWN IQ vs TWO-WIRE CLOCK FREQUENCY 300 5 4 5V +Error 250 VS = 5V 3 3.3V +Error 2 200 1 IQ (mA) % Bus Voltage Error 100 ACTIVE IQ vs TWO-WIRE CLOCK FREQUENCY 16 12 IQ (mA) -25 VIN- Voltage (V) 0 -1 150 100 -2 -3 50 5V -Error -4 VS = 3V 3.3V -Error 0 -5 0 1 2 3 4 5 24 25 26 1k 10k 100k VBUS (V) SCL Frequency (Hz) Figure 11. Figure 12. 1M Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 10M 7 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com REGISTER BLOCK DIAGRAM Power (1) Bus Voltage (1) ´ Current Shunt Voltage Channel (1) ADC Bus Voltage Channel Calibration (2) ´ Shunt Voltage (1) PGA (In Configuration Register) Data Registers (1) Read-only. (2) Write-only. Figure 13. INA220 Register Block Diagram 8 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 APPLICATION INFORMATION The INA220 is a digital current-shunt monitor with an Two-Wire and SMBus-compatible interface. It provides digital current, voltage, and power readings necessary for accurate decision-making in precisely-controlled systems. Programmable registers allow flexible configuration for measurement resolution, and continuous-versustriggered operation. Detailed register information appears at the end of this data sheet, beginning with Table 2. See the Register Block Diagram for a block diagram of the INA220. Data transfer is then initiated and eight bits of data are sent, followed by an Acknowledge bit. During data transfer, SDA must remain stable while SCL is HIGH. Any change in SDA while SCL is HIGH is interpreted as a START or STOP condition. Once all data have been transferred, the master generates a STOP condition, indicated by pulling SDA from LOW to HIGH while SCL is HIGH. The INA220 includes a 28ms timeout on its interface to prevent locking up an SMBus. INA220 TYPICAL APPLICATION Serial Bus Address The figure on the front page shows a typical application circuit for the INA220. Use a 0.1µF ceramic capacitor for power-supply bypassing, placed as closely as possible to the supply and ground pins. To communicate with the INA220, the master must first address slave devices via a slave address byte. The slave address byte consists of seven address bits, and a direction bit indicating the intent of executing a read or write operation. The input filter circuit consisting of RF1, RF2, and CF is not necessary in most applications. If the need for filtering is unknown, reserve board space for the components and install 0Ω resistors unless a filter is needed. See the Filtering and Input Considerations section. BUS OVERVIEW The INA220 offers compatibility with both Two-Wire and SMBus interfaces. The Two-Wire and SMBus protocols are essentially compatible with one another. The Two-Wire interface is used throughout this data sheet as the primary example, with SMBus protocol specified only when a difference between the two systems is being addressed. Two bidirectional lines, SCL and SDA, connect the INA220 to the bus. Both SCL and SDA are open-drain connections. The device that initiates the transfer is called a master, and the devices controlled by the master are slaves. The bus must be controlled by a master device that generates the serial clock (SCL), controls the bus access, and generates START and STOP conditions. To address a specific device, the master initiates a START condition by pulling the data signal line (SDA) from a HIGH to a LOW logic level while SCL is HIGH. All slaves on the bus shift in the slave address byte on the rising edge of SCL, with the last bit indicating whether a read or write operation is intended. During the ninth clock pulse, the slave being addressed responds to the master by generating an Acknowledge and pulling SDA LOW. The INA220 has two address pins, A0 and A1. Table 1 describes the pin logic levels for each of the 16 possible addresses. The state of pins A0 and A1 is sampled on every bus communication and should be set before any activity on the interface occurs. The address pins are read at the start of each communication event. Table 1. INA220 Address Pins and Slave Addresses A1 A0 SLAVE ADDRESS GND GND 1000000 GND VS+ 1000001 GND SDA 1000010 GND SCL 1000011 VS+ GND 1000100 VS+ VS+ 1000101 VS+ SDA 1000110 VS+ SCL 1000111 SDA GND 1001000 SDA VS+ 1001001 SDA SDA 1001010 SDA SCL 1001011 SCL GND 1001100 SCL VS+ 1001101 SCL SDA 1001110 SCL SCL 1001111 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 9 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com Serial Interface The INA220 operates only as a slave device on the Two-Wire bus and SMBus. Connections to the bus are made via the open-drain I/O lines SDA and SCL. The SDA and SCL pins feature integrated spike suppression filters and Schmitt triggers to minimize the effects of input spikes and bus noise. The INA220 supports the transmission protocol for fast (1kHz to 400kHz) and high-speed (1kHz to 3.4MHz) modes. All data bytes are transmitted most significant byte first. WRITING TO/READING FROM THE INA220 Accessing a particular register on the INA220 is accomplished by writing the appropriate value to the register pointer. Refer to Table 2 for a complete list of registers and corresponding addresses. The value for the register pointer as shown in Figure 17 is the first byte transferred after the slave address byte with the R/W bit LOW. Every write operation to the INA220 requires a value for the register pointer. Writing to a register begins with the first byte transmitted by the master. This byte is the slave address, with the R/W bit LOW. The INA220 then acknowledges receipt of a valid address. The next byte transmitted by the master is the address of the register to which data will be written. This register address value updates the register pointer to the desired register. The next two bytes are written to the register addressed by the register pointer. The INA220 acknowledges receipt of each data byte. The master may terminate data transfer by generating a START or STOP condition. 10 When reading from the INA220, the last value stored in the register pointer by a write operation determines which register is read during a read operation. To change the register pointer for a read operation, a new value must be written to the register pointer. This write is accomplished by issuing a slave address byte with the R/W bit LOW, followed by the register pointer byte. No additional data are required. The master then generates a START condition and sends the slave address byte with the R/W bit HIGH to initiate the read command. The next byte is transmitted by the slave and is the most significant byte of the register indicated by the register pointer. This byte is followed by an Acknowledge from the master; then the slave transmits the least significant byte. The master acknowledges receipt of the data byte. The master may terminate data transfer by generating a Not-Acknowledge after receiving any data byte, or generating a START or STOP condition. If repeated reads from the same register are desired, it is not necessary to continually send the register pointer bytes; the INA220 retains the register pointer value until it is changed by the next write operation. Figure 14 and Figure 15 show read and write operation timing diagrams, respectively. Note that register bytes are sent most-significant byte first, followed by the least significant byte. Figure 16 shows the timing diagram for the SMBus Alert response operation. Figure 17 illustrates a typical register pointer configuration. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 Start By Master 1 1 1 1 0 0 A3 A2 A1 A0 (1) R/W Frame 1 Two-Wire Slave Address Byte 0 A3 A2 A1 A0 (1) 9 ACK By INA220 R/W 1 P7 P6 9 ACK By INA220 1 D15 D14 P4 P3 P2 D13 P1 Frame 2 Register Pointer Byte P5 D12 D11 D10 D9 (2) From INA220 Frame 2 Data MSByte 9 ACK By INA220 P0 1 D15 D14 D13 D8 9 1 D6 9 ACK By INA220 D8 D7 ACK By Master D9 Frame 3 Data MSByte D12 D11 D10 NOTES: (1) The value of the Slave Address Byte is determined by the settings of the A0 and A1 pins. Refer to Table 1. (2) Read data is from the last register pointer location. If a new register is desired, the register pointer must be updated. See Figure 19. (3) ACK by Master can also be sent. 0 Frame 1 Two-Wire Slave Address Byte D5 1 D7 D4 D3 From INA220 D5 D4 D2 D3 D1 (2) D2 Frame 3 Data LSByte D6 9 9 ACK By INA220 D0 No ACK By Master D0 D1 Frame 4 Data LSByte (3) Stop Stop By Master Product Folder Link(s): INA220 11 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated SCL SDA SCL SDA Start By Master NOTE (1): The value of the Slave Address Byte is determined by the settings of the A0 and A1 pins. Refer to Table 1. Figure 15. Timing Diagram for Read Word Format Figure 14. Timing Diagram for Write Word Format INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com ALERT 1 9 1 9 SCL SDA 0 0 0 1 1 0 0 1 R/W Start By Master 0 0 A3 A2 ACK By INA220 A1 A0 0 From INA220 Frame 1 SMBus ALERT Response Address Byte Frame 2 Slave Address Byte NACK By Master Stop By Master (1) NOTE (1): The value of the Slave Address Byte is determined by the settings of the A0 and A1 pins. Refer to Table 1. Figure 16. Timing Diagram for SMBus ALERT 1 9 1 9 SCL ¼ SDA 1 0 0 A3 A2 A1 A0 R/W Start By Master P7 P6 P5 P4 P3 P2 P1 ACK By INA220 Frame 1 Two-Wire Slave Address Byte (1) P0 Stop ACK By INA220 Frame 2 Register Pointer Byte NOTE (1): The value of the Slave Address Byte is determined by the settings of the A0 and A1 pins. Refer to Table 1. Figure 17. Typical Register Pointer Set 12 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 High-Speed Two-Wire Mode The master then generates a repeated start condition (a repeated start condition has the same timing as the start condition). After this repeated start condition, the protocol is the same as F/S mode, except that transmission speeds up to 3.4Mbps are allowed. Instead of using a stop condition, repeated start conditions should be used to secure the bus in HS-mode. A stop condition ends the HS-mode and switches all the internal filters of the INA220 to support the F/S mode. When the bus is idle, both the SDA and SCL lines are pulled high by the pull-up devices. The master generates a start condition followed by a valid serial byte containing High-Speed (HS) master code 00001XXX. This transmission is made in fast (400kbps) or standard (100kbps) (F/S) mode at no more than 400kbps. The INA220 does not acknowledge the HS master code, but does recognize it and switches its internal filters to support 3.4Mbps operation. t(LOW) tF tR t(HDSTA) SCL t(HDSTA) t(HIGH) t(SUSTO) t(SUSTA) t(HDDAT) t(SUDAT) SDA t(BUF) P S S P Figure 18. Bus Timing Diagram Bus Timing Diagram Definitions FAST MODE PARAMETER HIGH-SPEED MODE MIN MAX MIN MAX UNITS SCL Operating Frequency f(SCL) 0.001 0.4 0.001 3.4 MHz Bus Free Time Between STOP and START Condition t(BUF) 600 160 ns Hold time after repeated START condition. After this period, the first clock is generated. t(HDSTA) 100 100 ns Repeated START Condition Setup Time t(SUSTA) 100 100 ns STOP Condition Setup Time t(SUSTO) 100 100 ns Data Hold Time t(HDDAT) 0 0 ns Data Setup Time t(SUDAT) 100 10 ns SCL Clock LOW Period t(LOW) 1300 160 ns SCL Clock HIGH Period t(HIGH) 600 Clock/Data Fall Time tF 300 160 ns Clock/Data Rise Time tR 300 160 ns Clock/Data Rise Time for SCLK ≤ 100kHz tR 1000 60 ns ns Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 13 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com Power-Up Conditions Power-up conditions apply to a software reset via the RST bit (bit 15) in the Configuration Register, or the Two-Wire bus General Call Reset. BASIC ADC FUNCTIONS The two analog inputs to the INA220, VIN+ and VIN–, connect to a shunt resistor in the bus of interest. Bus voltage is measured at VBUS pin. The INA220 is typically powered by a separate supply from +3V to +5.5V. The bus being sensed can vary from 0V to 26V. There are no special considerations for power-supply sequencing (for example, a bus voltage can be present with the supply voltage off, and vice-versa). The INA220 senses the small drop across the shunt for shunt voltage, and senses the voltage with respect to ground from VBUS for the bus voltage. When the INA220 is in the normal operating mode (that is, MODE bits of the Configuration Register are set to '111'), it continuously converts the shunt voltage up to the number set in the shunt voltage averaging function (Configuration Register, SADC bits). The device then converts the bus voltage up to the number set in the bus voltage averaging (Configuration Register, BADC bits). The Mode control in the Configuration Register also permits selecting modes to convert only voltage or current, either continuously or in response to an event (triggered). All current and power calculations are performed in the background and do not contribute to conversion time; conversion times shown in the Electrical Characteristics table can be used to determine the actual conversion time. Power-Down mode reduces the quiescent current and turns off current into the INA220 inputs, avoiding any supply drain. Full recovery from Power-Down requires 40µs. ADC Off mode (set by the Configuration Register, MODE bits) stops all conversions. In triggered mode, writing any of the triggered convert modes into the Configuration Register (even if the desired mode is already programmed into the register) triggers a single-shot conversion. Although the INA220 can be read at any time, and the data from the last conversion remain available, the Conversion Ready bit (Status Register, CNVR bit) is provided to help co-ordinate one-shot or triggered conversions. The Conversion Ready bit is set after all conversions, averaging, and multiplication operations are complete. space 14 The Conversion Ready bit clears under these conditions: 1. Writing to the Configuration Register, except when configuring the MODE bits for Power Down or ADC off (Disable) modes; 2. Reading the Status Register; or 3. Triggering a single-shot conversion with the Convert pin. Power Measurement Current and bus voltage are converted at different points in time, depending on the resolution and averaging mode settings. For instance, when configured for 12-bit and 128 sample averaging, up to 68ms in time between sampling these two values is possible. Again, these calculations are performed in the background and do not add to the overall conversion time. PGA Function If larger full-scale shunt voltages are desired, the INA220 provides a PGA function that increases the full-scale range up to 2, 4, or 8 times (320mV). Additionally, the bus voltage measurement has two full-scale ranges: 16V or 32V. Compatibility with TI Hot Swap Controllers The INA220 is designed for compatibility with hot swap controllers such the TI TPS2490. The TPS2490 uses a high-side shunt with a limit at 50mV; the INA220 full-scale range of 40mV enables the use of the same shunt for current sensing below this limit. When sensing is required at (or through) the 50mV sense point of the TPS2490, the PGA of the INA220 can be set to ÷2 to provide an 80mV full-scale range. Filtering and Input Considerations Measuring current is often noisy, and such noise can be difficult to define. The INA220 offers several options for filtering by choosing resolution and averaging in the Configuration Register. These filtering options can be set independently for either voltage or current measurement. The internal ADC is based on a delta-sigma (ΔΣ) front-end with a 500kHz (±30%) typical sampling rate. This architecture has good inherent noise rejection; however, transients that occur at or very close to the sampling rate harmonics can cause problems. Because these signals are at 1MHz and higher, they can be dealt with by incorporating filtering at the input of the INA220. The high frequency enables the use of low-value series resistors on the filter for negligible effects on measurement accuracy. In general, filtering the INA220 input is only necessary if there are transients at exact harmonics of the 500kHz (±30%) Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 sampling rate (>1MHz). Filter using the lowest possible series resistance and ceramic capacitor. Recommended values are 0.1µF to 1.0µF. Figure 19 shows the INA220 with an additonal filter added at the input. available. Testing has demonstrated that the addition of 10Ω resistors in series with each input of the INA220 sufficiently protects the inputs against dV/dt failure up to the 26V rating of the INA220. These resistors have no significant effect on accuracy. Overload conditions are another consideration for the INA220 inputs. The INA220 inputs are specified to tolerate 26V across the inputs. A large differential scenario might be a short to ground on the load side of the shunt. This type of event can result in full power-supply voltage across the shunt (as long the power supply or energy storage capacitors support it). It must be remembered that removing a short to ground can result in inductive kickbacks that could exceed the 26V differential and common-mode rating of the INA220. Inductive kickback voltages are best dealt with by zener-type transient-absorbing devices (commonly called transzorbs) combined with sufficient energy storage capacitance. Simple Current Shunt Monitor Usage (No Programming Necessary) In applications that do not have large energy storage electrolytics on one or both sides of the shunt, an input overstress condition may result from an excessive dV/dt of the voltage applied to the input. A hard physical short is the most likely cause of this event, particularly in applications with no large electrolytics present. This problem occurs because an excessive dV/dt can activate the ESD protection in the INA220 in systems where large currents are Programming the INA220 The INA220 can be used without any programming if it is only necessary to read a shunt voltage drop and bus voltage with the default 12-bit resolution, 320mV shunt full-scale range (PGA=÷8), 32V bus full-scale range, and continuous conversion of shunt and bus voltage. Without programming, current is measured by reading the shunt voltage. The Current Register and Power Register are only available if the Calibration Register contains a programmed value. The default power-up states of the registers are shown in the INA220 register descriptions section of this data sheet. These registers are volatile, and if programmed to other than default values, must be re-programmed at every device power-up. Detailed information on programming the Calibration Register specifically is given in the section, Programming the INA220 Power Measurement Engine. Current Shunt Load Supply RFILTER 10W RFILTER 10W Supply Voltage 3.3V Supply VBUS 0.1mF to 1mF Ceramic Capacitor VIN+ VIN- VS INA220 ´ Power Register Current Register Data (SDA) Two-Wire Interface Clock (SCL) A0 ADC Voltage Register A1 GND Figure 19. INA220 with Input Filtering Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 15 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com PROGRAMMING THE INA220 POWER MEASUREMENT ENGINE Calibration Register and Scaling The Calibration Register makes it possible to set the scaling of the Current and Power Registers to whatever values are most useful for a given application. One strategy may be to set the Calibration Register such that the largest possible number is generated in the Current Register or Power Register at the expected full-scale point; this approach yields the highest resolution. The Calibration Register can also be selected to provide values in the Current and Power Registers that either provide direct decimal equivalents of the values being measured, or yield a round LSB number. After these choices have been made, the Calibration Register also offers possibilities for end user system-level calibration, where the value is adjusted slightly to cancel total system error. Below are two examples for configuring the INA220 calibration. Both examples are written so the information directly relates to the calibration setup found in the INA220EVM software. Calibration Example 1: Calibrating the INA220 with no possibility for overflow. (Note that the numbers used in this example are the same used with the INA220EVM software as shown in Figure 20.) 1. Establish the following parameters: VBUS_MAX = 32 VSHUNT_MAX = 0.32 RSHUNT = 0.5 2. Using Equation 1, determine the maximum possible current . VSHUNT_MAX MaxPossible_I = RSHUNT MaxPossible_I = 0.64 (1) 3. Choose the desired maximum current value. This value is selected based on system expectations. Max_Expected_I = 0.6 4. Calculate the possible range of current LSBs. To calculate this range, first compute a range of LSBs that is appropriate for the design. Next, select an LSB within this range. Note that the results will have the most resolution when the minimum LSB is selected. Typically, an LSB is selected to be the nearest round number to the minimum LSB value. Max_Expected_I Minimum_LSB = 32767 Minimum_LSB = 18.311 ´ 10-6 (2) Max_Expected_I 4096 Maximum_LSB = 146.520 ´ 10-6 Maximum_LSB = (3) Choose an LSB in the range: Minimum_LSB<Selected_LSB < Maximum_LSB Current_LSB = 20 × 10–6 Note: This value was selected to be a round number near the Minimum_LSB. This selection allows for good resolution with a rounded LSB. 5. Compute the Calibration Register value using Equation 4: 0.04096 Cal = trunc Current_LSB ´ R SHUNT Cal = 4096 16 (4) Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 6. Calculate the Power LSB, using Equation 5. Equation 5 shows a general formula; because the bus voltage measurement LSB is always 4mV, the power formula reduces to the calculated result. Power_LSB = 20 Current_LSB Power_LSB = 400 ´ 10-6 (5) 7. Compute the maximum current and shunt voltage values (before overflow), as shown by Equation 6 and Equation 7. Note that both Equation 6 and Equation 7 involve an If - then condition: Max_Current = Current_LSB ´ 32767 Max_Current = 0.65534 (6) If Max_Current ≥ Max Possible_I then Max_Current_Before_Overflow = MaxPossible_I Else Max_Current_Before_Overflow = Max_Current End If (Note that Max_Current is greater than MaxPossible_I in this example.) Max_Current_Before_Overflow = 0.64 (Note: This result is displayed by software as seen in Figure 20.) Max_ShuntVoltage = Max_Current_Before_Overflow ´ RSHUNT Max_ShuntVoltage = 0.32 (7) If Max_ShuntVoltage ≥ VSHUNT_MAX Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX Else Max_ShuntVoltage_Before_Overflow= Max_ShuntVoltage End If (Note that Max_ShuntVoltage is greater than VSHUNT_MAX in this example.) Max_ShuntVoltage_Before_Overflow = 0.32 (Note: This result is displayed by software as seen in Figure 20.) 8. Compute the maximum power with Equation 8. MaximumPower = Max_Current_Before_Overflow ´ VBUS_MAX MaximumPower = 20.48 (8) 9. (Optional second Calibration step.) Compute corrected full-scale calibration value based on measured current. INA220_Current = 0.63484 MeaShuntCurrent = 0.55 Corrected_Full_Scale_Cal = trunc Cal ´ MeasShuntCurrent INA220_Current Corrected_Full_Scale_Cal = 3548 (9) Figure 20 illustrates how to perform the same procedure discussed in this example using the automated INA220EVM software. Note that the same numbers used in the nine-step example are used in the software example in Figure 20. Also note that Figure 20 illustrates which results correspond to which step (for example, the information entered in Step 1 is enclosed in a box in Figure 20 and labeled). Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 17 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com Figure 20. INA220EVM Calibration Sofware Automatically Computes Calibration Steps 1-9 18 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 Calibration Example 2 (Overflow Possible) This design example uses the nine-step procedure for calibrating the INA220 where overflow is possible. Figure 21 illustrates how the same procedure is performed using the automated INA220EVM software. Note that the same numbers used in the nine-step example are used in the software example in Figure 21. Also note that Figure 21 illustrates which results correspond to which step (for example, the information entered in Step 1 is circled in Figure 21 and labeled). 1. Establish the following parameters: VBUS_MAX = 32 VSHUNT_MAX = 0.32 RSHUNT = 5 2. Determine the maximum possible current using Equation 10: VSHUNT_MAX MaxPossible_I = RSHUNT MaxPossible_I = 0.064 (10) 3. Choose the desired maximum current value: Max_Expected_I, ≤ MaxPossible_I. This value is selected based on system expectations. Max_Expected_I = 0.06 4. Calculate the possible range of current LSBs. This calculation is done by first computing a range of LSB's that is appropriate for the design. Next, select an LSB withing this range. Note that the results will have the most resolution when the minimum LSB is selected. Typically, an LSB is selected to be the nearest round number to the minimum LSB. Max_Expected_I Minimum_LSB = 32767 Minimum_LSB = 1.831 ´ 10-6 (11) Max_Expected_I 4096 Maximum_LSB = 14.652 ´ 10-6 Maximum_LSB = (12) Choose an LSB in the range: Minimum_LSB<Selected_LSB<Maximum_LSB Current_LSB = 1.9 × 10–6 Note: This value was selected to be a round number near the Minimum_LSB. This section allows for good resolution with a rounded LSB. 5. Compute the calibration register using Equation 13: Cal = trunc 0.04096 Current_LSB ´ RSHUNT Cal = 4311 (13) 6. Calculate the Power LSB using Equation 14. Equation 14 shows a general formula; because the bus voltage measurement LSB is always 4mV, the power formula reduces to calculate the result. Power_LSB = 20 Current_LSB Power_LSB = 38 ´ 10-6 (14) Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 19 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com 7. Compute the maximum current and shunt voltage values (before overflow), as shown by Equation 15 and Equation 16. Note that both Equation 15 and Equation 16 involve an If - then condition. Max_Current = Current_LSB ´ 32767 Max_Current = 0.06226 (15) If Max_Current ≥ Max Possible_I then Max_Current_Before_Overflow = MaxPossible_I Else Max_Current_Before_Overflow = Max_Current End If (Note that Max_Current is less than MaxPossible_I in this example.) Max_Current_Before_Overflow = 0.06226 (Note: This result is displayed by software as seen in Figure 21.) Max_ShuntVoltage = Max_Current_Before_Overflow ´ RSHUNT Max_ShuntVoltage = 0.3113 (16) If Max_ShuntVoltage ≥ VSHUNT_MAX Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX Else Max_ShuntVoltage_Before_Overflow= Max_ShuntVoltage End If (Note that Max_ShuntVoltage is less than VSHUNT_MAX in this example.) Max_ShuntVoltage_Before_Overflow = 0.3113 (Note: This result is displayed by software as seen in Figure 21.) 8. Compute the maximum power with equation 8. MaximumPower = Max_Current_Before_Overflow ´ VBUS_MAX MaximumPower = 1.992 (17) 9. (Optional second calibration step.) Compute the corrected full-scale calibration value based on measured current. INA220_Current = 0.06226 MeaShuntCurrent = 0.05 Corrected_Full_Scale_Cal = trunc Cal ´ MeasShuntCurrent INA220_Current Corrected_Full_Scale_Cal = 3462 (18) Figure 21 illustrates how to perform the same procedure discussed in this example using the automated INA220EVM software. Note that the same numbers used in the nine-step example are used in the software example in Figure 21. Also note that Figure 21 illustrates which results correspond to which step (for example, the information entered in Step 1 is enclosed in a box in Figure 21 and labeled). 20 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 Figure 21. INA220EVM Calibration Software Automatically Computes Calibration Steps 1-9 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 21 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com REGISTER INFORMATION The INA220 uses a bank of registers for holding configuration settings, measurement results, maximum/minimum limits, and status information. Table 2 summarizes the INA220 registers; Figure 13 illustrates registers. Register contents are updated 4µs after completion of the write command. Therefore, a 4µs delay is required between completion of a write to a given register and a subsequent read of that register (without changing the pointer) when using SCL frequencies in excess of 1MHz. Table 2. Summary of Register Set POINTER ADDRESS (1) (2) 22 POWER-ON RESET BINARY HEX TYPE (1) All-register reset, settings for bus voltage range, PGA Gain, ADC resolution/averaging. 00111001 10011111 399F R/W Shunt voltage measurement data. Shunt voltage — R Bus voltage — R Power measurement data. 00000000 00000000 0000 R Current (2) Contains the value of the current flowing through the shunt resistor. 00000000 00000000 0000 R Calibration Sets full-scale range and LSB of current and power measurements. Overall system calibration. 00000000 00000000 0000 R/W HEX REGISTER NAME 00 Configuration Register 01 Shunt Voltage 02 Bus Voltage 03 Power (2) 04 05 FUNCTION Bus voltage measurement data. Type: R = Read-Only, R/W = Read/Write. The Power Register and Current Register default to '0' because the Calibration Register defaults to '0', yielding a zero current value until the Calibration Register is programmed. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 REGISTER DETAILS All INA220 registers 16-bit registers are actually two 8-bit bytes via the Two-Wire interface. Configuration Register 00h (Read/Write) BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME RST — BRNG PG1 PG0 BADC4 BADC3 BADC2 BADC1 SADC4 SADC3 SADC2 SADC1 MODE3 MODE2 MODE1 POR VALUE 0 0 1 1 1 0 0 1 1 0 0 1 1 1 1 1 Bit Descriptions RST: Reset Bit Bit 15 Setting this bit to '1' generates a system reset that is the same as power-on reset. Resets all registers to default values; this bit self-clears. BRNG: Bus Voltage Range Bit 13 0 = 16V FSR 1 = 32V FSR (default value) PG: PGA (Shunt Voltage Only) Bits 11, 12 Sets PGA gain and range. Note that the PGA defaults to ÷8 (320mV range). Table 3 shows the gain and range for the various product gain settings. Table 3. PG Bit Settings [12:11] (1) (1) PG1 PG0 GAIN RANGE 0 0 1 ±40mV 0 1 ÷2 ±80mV 1 0 ÷4 ±160mV 1 1 ÷8 ±320mV Shaded values are default. BADC: BADC Bus ADC Resolution/Averaging Bits 7–10 These bits adjust the Bus ADC resolution (9-, 10-, 11-, or 12-bit) or set the number of samples used when averaging results for the Bus Voltage Register (02h). Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 23 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com SADC: SADC Shunt ADC Resolution/Averaging Bits 3–6 These bits adjust the Shunt ADC resolution (9-, 10-, 11-, or 12-bit) or set the number of samples used when averaging results for the Shunt Voltage Register (01h). BADC (Bus) and SADC (Shunt) ADC resolution/averaging and conversion time settings are shown in Table 4. Table 4. ADC Settings (SADC [6:3], BADC [10:7]) (1) ADC4 (1) (2) ADC3 ADC2 ADC1 0 X (2) 0 0 9-bit 84µs 0 X (2) 0 1 10-bit 148µs 0 X (2) 1 0 11-bit 276µs 0 (2) 1 1 12-bit 532µs 1 0 0 0 12-bit 532µs 1 0 0 1 2 1.06ms 1 0 1 0 4 2.13ms 1 0 1 1 8 4.26ms 1 1 0 0 16 8.51ms 1 1 0 1 32 17.02ms 1 1 1 0 64 34.05ms 1 1 1 1 128 68.10ms X MODE/SAMPLES CONVERSION TIME Shaded values are default. X = Don't care. MODE: Operating Mode Bits 0–2 Selects continuous, triggered, or power-down mode of operation. These bits default to continuous shunt and bus measurement mode. The mode settings are shown in Table 5. Table 5. Mode Settings [2:0] (1) (1) 24 MODE3 MODE2 MODE1 MODE 0 0 0 Power-Down 0 0 1 Shunt Voltage, Triggered 0 1 0 Bus Voltage, Triggered 0 1 1 Shunt and Bus, Triggered 1 0 0 ADC Off (disabled) 1 0 1 Shunt Voltage, Continuous 1 1 0 Bus Voltage, Continuous 1 1 1 Shunt and Bus, Continuous Shaded values are default. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 DATA OUTPUT REGISTERS Shunt Voltage Register 01h (Read-Only) The Shunt Voltage Register stores the current shunt voltage reading, VSHUNT. Shunt Voltage Register bits are shifted according to the PGA setting selected in the Configuration Register (00h). When multiple sign bits are present, they will all be the same value. Negative numbers are represented in twos complement format. Generate the twos complement of a negative number by complementing the absolute value binary number and adding 1. Extend the sign, denoting a negative number by setting the MSB = '1'. Extend the sign to any additional sign bits to form the 16-bit word. Example: For a value of VSHUNT = –320mV: 1. Take the absolute value (include accuracy to 0.01mV)==> 320.00 2. Translate this number to a whole decimal number ==> 32000 3. Convert it to binary==> 111 1101 0000 0000 4. Complement the binary result : 000 0010 1111 1111 5. Add 1 to the complement to create the twos complement formatted result ==> 000 0011 0000 0000 6. Extend the sign and create the 16-bit word: 1000 0011 0000 0000 = 8300h (Remember to extend the sign to all sign-bits, as necessary based on the PGA setting.) At PGA = ÷8, full-scale range = ±320mV (decimal = 32000, positive value hex = 7D00, negative value hex = 8300), and LSB = 10µV. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME SIGN SD14_8 SD13_8 SD12_8 SD11_8 SD10_8 SD9_8 SD8_8 SD7_8 SD6_8 SD5_8 SD4_8 SD3_8 SD2_8 SD1_8 SD0_8 POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 At PGA = ÷4, full-scale range = ±160mV (decimal = 16000, positive value hex = 3E80, negative value hex = C180), and LSB = 10µV. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME SIGN SIGN SD13_4 SD12_4 SD11_4 SD10_4 SD9_4 SD8_4 SD7_4 SD6_4 SD5_4 SD4_4 SD3_4 SD2_4 SD1_4 SD0_4 POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 At PGA = ÷2, full-scale range = ±80mV (decimal = 8000, positive value hex = 1F40, negative value hex = E0C0), and LSB = 10µV. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME SIGN SIGN SIGN SD12_2 SD11_2 SD10_2 SD9_2 SD8_2 SD7_2 SD6_2 SD5_2 SD4_2 SD3_2 SD2_2 SD1_2 SD0_2 POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 At PGA = ÷1, full-scale range = ±40mV (decimal = 4000, positive value hex = 0FA0, negative value hex = F060), and LSB = 10µV. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME SIGN SIGN SIGN SIGN SD11_1 SD10_1 SD9_1 SD8_1 SD7_1 SD6_1 SD5_1 SD4_1 SD3_1 SD2_1 SD1_1 SD0_1 POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 25 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com Table 6. Shunt Voltage Register Format (1) VSHUNT Reading (mV) Decimal Value PGA = ÷ 8 (D15…..................D0) PGA = ÷ 4 (D15…..................D0) PGA = ÷ 2 (D15…..................D0) PGA = ÷ 1 (D15…..................D0) 320.02 32002 0111 1101 0000 0000 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 320.01 32001 0111 1101 0000 0000 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 320.00 32000 0111 1101 0000 0000 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 319.99 31999 0111 1100 1111 1111 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 319.98 31998 0111 1100 1111 1110 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 160.02 16002 0011 1110 1000 0010 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 160.01 16001 0011 1110 1000 0001 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 160.00 16000 0011 1110 1000 0000 0011 1110 1000 0000 0001 1111 0100 0000 0000 1111 1010 0000 159.99 15999 0011 1110 0111 1111 0011 1110 0111 1111 0001 1111 0100 0000 0000 1111 1010 0000 159.98 15998 0011 1110 0111 1110 0011 1110 0111 1110 0001 1111 0100 0000 0000 1111 1010 0000 80.02 8002 0001 1111 0100 0010 0001 1111 0100 0010 0001 1111 0100 0000 0000 1111 1010 0000 80.01 8001 0001 1111 0100 0001 0001 1111 0100 0001 0001 1111 0100 0000 0000 1111 1010 0000 80.00 8000 0001 1111 0100 0000 0001 1111 0100 0000 0001 1111 0100 0000 0000 1111 1010 0000 79.99 7999 0001 1111 0011 1111 0001 1111 0011 1111 0001 1111 0011 1111 0000 1111 1010 0000 79.98 7998 0001 1111 0011 1110 0001 1111 0011 1110 0001 1111 0011 1110 0000 1111 1010 0000 40.02 4002 0000 1111 1010 0010 0000 1111 1010 0010 0000 1111 1010 0010 0000 1111 1010 0000 40.01 4001 0000 1111 1010 0001 0000 1111 1010 0001 0000 1111 1010 0001 0000 1111 1010 0000 40.00 4000 0000 1111 1010 0000 0000 1111 1010 0000 0000 1111 1010 0000 0000 1111 1010 0000 39.99 3999 0000 1111 1001 1111 0000 1111 1001 1111 0000 1111 1001 1111 0000 1111 1001 1111 39.98 3998 0000 1111 1001 1110 0000 1111 1001 1110 0000 1111 1001 1110 0000 1111 1001 1110 0.02 2 0000 0000 0000 0010 0000 0000 0000 0010 0000 0000 0000 0010 0000 0000 0000 0010 0.01 1 0000 0000 0000 0001 0000 0000 0000 0001 0000 0000 0000 0001 0000 0000 0000 0001 0 0 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 –0.01 –1 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 –0.02 –2 1111 1111 1111 1110 1111 1111 1111 1110 1111 1111 1111 1110 1111 1111 1111 1110 –39.98 –3998 1111 0000 0110 0010 1111 0000 0110 0010 1111 0000 0110 0010 1111 0000 0110 0010 –39.99 –3999 1111 0000 0110 0001 1111 0000 0110 0001 1111 0000 0110 0001 1111 0000 0110 0001 –40.00 –4000 1111 0000 0110 0000 1111 0000 0110 0000 1111 0000 0110 0000 1111 0000 0110 0000 –40.01 –4001 1111 0000 0101 1111 1111 0000 0101 1111 1111 0000 0101 1111 1111 0000 0110 0000 –40.02 –4002 1111 0000 0101 1110 1111 0000 0101 1110 1111 0000 0101 1110 1111 0000 0110 0000 –79.98 –7998 1110 0000 1100 0010 1110 0000 1100 0010 1110 0000 1100 0010 1111 0000 0110 0000 –79.99 –7999 1110 0000 1100 0001 1110 0000 1100 0001 1110 0000 1100 0001 1111 0000 0110 0000 –80.00 –8000 1110 0000 1100 0000 1110 0000 1100 0000 1110 0000 1100 0000 1111 0000 0110 0000 –80.01 –8001 1110 0000 1011 1111 1110 0000 1011 1111 1110 0000 1100 0000 1111 0000 0110 0000 –80.02 –8002 1110 0000 1011 1110 1110 0000 1011 1110 1110 0000 1100 0000 1111 0000 0110 0000 –159.98 –15998 1100 0001 1000 0010 1100 0001 1000 0010 1110 0000 1100 0000 1111 0000 0110 0000 –159.99 –15999 1100 0001 1000 0001 1100 0001 1000 0001 1110 0000 1100 0000 1111 0000 0110 0000 –160.00 –16000 1100 0001 1000 0000 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 –160.01 –16001 1100 0001 0111 1111 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 –160.02 –16002 1100 0001 0111 1110 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 –319.98 –31998 1000 0011 0000 0010 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 –319.99 –31999 1000 0011 0000 0001 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 –320.00 –32000 1000 0011 0000 0000 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 –320.01 –32001 1000 0011 0000 0000 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 –320.02 –32002 1000 0011 0000 0000 1100 0001 1000 0000 1110 0000 1100 0000 1111 0000 0110 0000 (1) 26 Out-of-range values are shown in grey shading. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 Bus Voltage Register 02h (Read-Only) The Bus Voltage Register stores the most recent bus voltage reading, VBUS. At full-scale range = 32V (decimal = 8000, hex = 1F40), and LSB = 4mV. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME BD12 BD11 BD10 BD9 BD8 BD7 BD6 BD5 BD4 BD3 BD2 BD1 BD0 — CNVR OVF POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 At full-scale range = 16V (decimal = 4000, hex = 0FA0), and LSB = 4mV. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME 0 BD11 BD10 BD9 BD8 BD7 BD6 BD5 BD4 BD3 BD2 BD1 BD0 — CNVR OVF POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 CNVR: Conversion Ready Bit 1 Although the data from the last conversion can be read at any time, the INA220 Conversion Ready bit (CNVR) indicates when data from a conversion is available in the data output registers. The CNVR bit is set after all conversions, averaging, and multiplications are complete. CNVR will clear under the following conditions: 1.) Writing a new mode into the Operating Mode bits in the Configuration Register (except for Power-Down or Disable) 2.) Reading the Power Register OVF: Math Overflow Flag Bit 0 The Math Overflow Flag (OVF) is set when the Power or Current calculations are out of range. It indicates that current and power data may be meaningless. Power Register 03h (Read-Only) Full-scale range and LSB are set by the Calibration Register. See the Programming the INA220 Power Measurement Engine section. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME PD15 PD14 PD13 PD12 PD11 PD10 PD9 PD8 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0 POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 The Power Register records power in watts by multiplying the values of the current with the value of the bus voltage according to the equation: Power = Current ´ BusVoltage 5000 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 27 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com Current Register 04h (Read-Only) Full-scale range and LSB depend on the value entered in the Calibration Register. See the Programming the INA220 Power Measurement Engine section. Negative values are stored in Two's Complement format. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 BIT NAME CSIGN CD14 CD13 CD12 CD11 CD10 CD9 CD8 CD7 CD6 CD5 CD4 CD3 CD2 CD1 CD0 POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 The value of the Current Register is calculated by multiplying the value in the Shunt Voltage Register with the value in the Calibration Register according to the equation: Current = ShuntVoltage ´ Calibration Register 4096 CALIBRATION REGISTER Calibration Register 05h (Read/Write) Current and power calibration are set by bits D15 to D1 of the Calibration Register. Note that bit D0 is not used in the calculation. This register sets the current that corresponds to a full-scale drop across the shunt. Full-scale range and the LSB of the current and power measurement depend on the value entered in this register. See the Programming the INA220 Power Measurement Engine section. This register is suitable for use in overall system calibration. Note that the '0' POR values are all default. BIT # D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 (1) BIT NAME FS15 FS14 FS13 FS12 FS11 FS10 FS9 FS8 FS7 FS6 FS5 FS4 FS3 FS2 FS1 FS0 POR VALUE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (1) 28 D0 is a void bit and will always be '0'. It is not possible to write a '1' to D0. CALIBRATION is the value stored in D15:D1. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 INA220 www.ti.com ............................................................................................................................................................. SBOS459B – JUNE 2009 – REVISED JUNE 2009 ADDITIONAL APPLICATION IDEAS Figure 22, Figure 23, and Figure 24 show the INA220 in additional circuit configurations for current, voltage, and power monitoring applications. HCPL2300 0.1mF +3.3V to +5V 1/4W Zener or shunt reg 0.1mF 4.3kW 4.3kW 1W 10mF -48V Supply 8 1 7 2 6 3 5 4 SDA 0.1mF 35.7kW +5V HCPL2300 VBUS (Bus Voltage Input) VS (Supply Voltage) INA220 13.7kW 24V Tranzorb 0.1mF 1 8 2 7 3 6 4 5 4.3kW Power Register Data V VIN+ Current Register Two-Wire Interface Clock A0 ADC VIN- Voltage Register GND -48V Supply 4.3kW A1 I HCPL2300 0.1mF 8 1 7 2 6 3 5 4 4.3kW SCL -48V to Load Shunt (40mV max for 12-bit) Figure 22. –48V Telecom Current/Voltage/Power Sense with Isolation From Supply Shunt RSHUNT Load RG +3.3V to +5V 100W MOSFET rated to standoff supply voltage such as BSS84 for up to 50V 10kW 5.1V Zener 0.1mF 35.7kW OPA333 10mF VBUS (Bus Voltage Input) VS (Supply Voltage) INA220 13.7kW 24V Tranzorb ´ V VIN+ RL 100W Power Register Current Register Two-Wire Interface Data (SDA) Clock (SCL) A0 ADC VIN- Voltage Register A1 I GND Figure 23. 48V Telecom Current/Voltage/Power Sense Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 29 INA220 SBOS459B – JUNE 2009 – REVISED JUNE 2009 ............................................................................................................................................................. www.ti.com CBYPASS 0.1mF +3.3V to +5V Bus Voltage Input VS (Supply Voltage) Load INA220 Battery ´ SDA Power Register DATA SCL Shunt (40mV max for 12-bit) R2F R1F V VIN+ Current Register Two-Wire Interface ADC CF CLK A0 A1 Voltage Register VIN- I Address Select GND Figure 24. General Source Low-Side Sensing space REVISION HISTORY NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision A (June, 2009) to Revision B ................................................................................................... Page • 30 Corrected ESD Ratings: Machine model and charged-device model ................................................................................... 2 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): INA220 PACKAGE OPTION ADDENDUM www.ti.com 30-Jun-2009 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty INA220AIDGSR ACTIVE MSOP DGS 10 2500 Green (RoHS & no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR INA220AIDGST ACTIVE MSOP DGS 10 250 CU NIPDAU Level-2-260C-1 YEAR Green (RoHS & no Sb/Br) Lead/Ball Finish MSL Peak Temp (3) (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. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 27-Jun-2009 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel Diameter Width (mm) W1 (mm) A0 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant INA220AIDGSR MSOP DGS 10 2500 330.0 12.4 5.3 3.3 1.3 8.0 12.0 Q1 INA220AIDGST MSOP DGS 10 250 180.0 12.4 5.3 3.3 1.3 8.0 12.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 27-Jun-2009 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) INA220AIDGSR MSOP DGS 10 2500 370.0 355.0 55.0 INA220AIDGST MSOP DGS 10 250 195.0 200.0 45.0 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. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Amplifiers Data Converters DLP® Products DSP Clocks and Timers Interface Logic Power Mgmt Microcontrollers RFID RF/IF and ZigBee® Solutions amplifier.ti.com dataconverter.ti.com www.dlp.com dsp.ti.com www.ti.com/clocks interface.ti.com logic.ti.com power.ti.com microcontroller.ti.com www.ti-rfid.com www.ti.com/lprf Applications Audio Automotive Broadband Digital Control Medical Military Optical Networking Security Telephony Video & Imaging Wireless www.ti.com/audio www.ti.com/automotive www.ti.com/broadband www.ti.com/digitalcontrol www.ti.com/medical www.ti.com/military www.ti.com/opticalnetwork www.ti.com/security www.ti.com/telephony www.ti.com/video www.ti.com/wireless Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2009, Texas Instruments Incorporated