• AEC-Q100 qualified for automotive applications:
  • Temperature grade 1: –40°C to +125°C, T_A
• Functional Safety-Capable
  • Documentation available to aid functional safety system design
• High-resolution, 16-bit delta-sigma ADC
• Current monitoring accuracy:
  • Offset voltage: ±50 µV (maximum)
  • Offset drift: ±0.02 µV/°C (maximum)
  • Gain error: ±0.3% (maximum)
  • Gain error drift: ±50 ppm/°C (maximum)
  • Common mode rejection: 120 dB (minimum)
• Power monitoring accuracy:
  • 1.6% full scale, –40°C to +125°C (maximum)
• Fast alert response: 75 μs
• Wide common-mode range: –0.3 V to +85 V
• Bus voltage sense input: 0 V to 85 V
• Shunt full-scale differential range:
  ±163.84 mV / ±40.96 mV
• Input bias current: 2.5 nA (maximum)
• Temperature sensor: ±1°C (maximum at 25°C)
• Programmable conversion time and averaging
• 2.94-MHz high-speed I²C interface with 16 pin-selectable addresses
• Operates from a 2.7-V to 5.5-V supply:
  • Operational current: 640 µA (typical)
  • Shutdown current: 5 µA (maximum)

• Automotive battery management systems
• EV / HEV A - KA sense applications
• DC/DC converters and power inverters
• ADAS domain controllers

The INA237-Q1 is an ultra-precise digital power monitor with a 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 INA237-Q1 reports current, bus voltage, temperature, and power, all while performing the needed calculations in the background. The integrated temperature sensor is ±1°C accurate for die temperature measurement and is useful in monitoring the system ambient temperature.

The low offset and gain drift design of the INA237-Q1 allows the device 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 micro-amp 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.

Simplified Block Diagram

at T_A = 25 °C, V_VS = 3.3 V, V_CM = 48 V, V_SENSE = 0, and V_VBUS = 48 V (unless otherwise noted)

VCM = 48 V

Figure 6-2 Shunt Input Offset Voltage Production Distribution

Figure 6-4 Shunt Input Offset Voltage vs. Temperature

Figure 6-6 Shunt Input Common-Mode Rejection Ratio vs. Temperature

VCM = 24 V

Figure 6-8 Shunt Input Gain Error vs. Temperature

VVBUS = 20 mV

Figure 6-10 Bus Input Offset Voltage Production Distribution

Figure 6-12 Bus Input Gain Error Production Distribution

Figure 6-14 Input Bias Current vs. Differential Input Voltage

Figure 6-16 Input Bias Current vs. Temperature

Figure 6-18 Active I_Q vs. Temperature

Figure 6-20 Shutdown I_Q vs. Supply Voltage

Figure 6-22 Active I_Q vs. Clock Frequency

Figure 6-24 Internal Clock Frequency vs. Power Supply

VCM = 0 V

Figure 6-3 Shunt Input Offset Voltage Production Distribution

Figure 6-5 Common-Mode Rejection Ratio Production Distribution

VCM = 24 V

Figure 6-7 Shunt Input Gain Error Production Distribution

Figure 6-9 Shunt Input Gain Error vs. Common-Mode Voltage

VVBUS = 20 mV

Figure 6-11 Bus Input Offset Voltage vs. Temperature

Figure 6-13 Bus Input Gain Error vs. Temperature

Figure 6-15 Input Bias Current (IB+ or IB–) vs. Common-Mode Voltage

Figure 6-17 Input Bias Current vs. Temperature, Shutdown

Figure 6-19 Active I_Q vs. Supply Voltage

Figure 6-21 Shutdown I_Q vs. Temperature

Figure 6-23 Shutdown I_Q vs. Clock Frequency

Figure 6-25 Internal Clock Frequency vs. Temperature