INA237-Q1

• High-resolution, 16-bit delta-sigma ADC
• Wide common-mode range: –0.3 V to +85 V
• Shunt full-scale differential range:
  ±163.84 mV / ± 40.96 mV
• Bus voltage sense input: 0 V to 85 V
• Accuracy
  • Offset voltage at 48 V_CM: ±75 µV (maximum)
  • Offset voltage at 0 V_CM: ±75 µV (maximum)
  • Offset drift: ±0.15 µV/°C (maximum)
  • Gain error: ±0.3% (maximum)
  • Gain error drift: ±50 ppm/°C (maximum)
  • Shunt voltage resolution:
    5 µV/LSB / 1.25 µV/LSB
  • Bus voltage resolution: 3.125 mV/LSB
• Input bias current: 5 nA (maximum)
• Internal temperature sensor: ±2 °C (maximum)
• Internal precision oscillator: ±1% (maximum)
• Programmable data rate and averaging
• Reports current, bus voltage, power, internal temperature,
• High-side and low-side applications
• 3-MHz High-Speed I²C interface with 16 pin-selectable addresses
• Operates from a 2.7-V to 5.5-V supply
  • Operational current: 660 µA
  • Shutdown current: 5 µA

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The INA237-Q1 is an ultra-precise digital power monitor with 16-bit delta-sigma ADC specifically designed for current-sensing applications. The device can measure a full-scale differential input of ±163.84 mV or ±40.96 mV across a resistive shunt sense element with common-mode voltage support from –0.3 V to +85 V.

The low offset and gain drift design of the INA237-Q1 allows it to be used in precise systems that do not undergo multi-temperature calibration during manufacturing. Further, the very low offset voltage and noise allow for use in A to kA sensing applications and provide a wide dynamic range without significant power dissipation losses on the sensing shunt element. The low input bias current of the device permits the use of larger current-sense resistors, thus providing accurate current measurements in the microamp range.

The device allows for selectable ADC conversion times from 50 µs to 4.12 ms as well as sample averaging from 1x to 1024x which further helps reduce the noise of the measured data.

The INA237-Q1 calculates power, all while performing calculations on a sample-by-sample basis for an accurate result. An integrated temperature sensor with error less than ±2 °C provides information about the ambient temperature of the system.

The INA237-Q1 integrates built-in diagnostics to indicate system health status as well as out-of-range conditions. This indication is provided by using the open-drain ALERT pin.

The INA237-Q1 operates from a single supply of 2.7-V to 5.5-V supply, drawing less than 660-µA current during operation and with less than 5-µA current during shutdown. Configurable continuous or single-shot triggered measurement provides further current consumption reduction. The output can be interfaced to an MCU or a battery management System-on-Chip devices through the I²C interface.

The device is specified over the operating range –40 °C to +125 °C.