Supervisor INA220AIDGSR high-side or low-side, bidirectional current and power monitor, two-wire interface 1

Features 1? High or low side sensing? Senses bus voltage from 0 VV? 26 reports current, voltage, and power?? High precision 16 programmable addresses: 0.5% (max) temperature (INA220B)? Calibrated? Fast (2.56 MHz) I2C - or SMBUS-Compatible interface? VSSOP-10 package

2Applications?Servers?Telecom Equipment?Laptops?Power Management?Battery Chargers?Car Power?Test Equipment

The INA220 is a current shunt and power monitor with an I2C or smbus compatible interface. The INA220 monitors the parallel buck and supply voltage simultaneously. A programmable calibration value, combined with an internal multiplier, enables direct amperage reading. Another multiply register calculates power in watts. I2C or smbus compatible interface with 16 programmable addresses. An independent shunt input on the supervisor INA220AIDGSR allows it to be used in low-side sensing systems.

The monitor INA220AIDGSR is available in two grades: Class A and Class B. The B-grade version has higher accuracy and higher accuracy specifications.

The supervisor INA220AIDGSR sensor spans the shunt bus and can vary from 0 to 26v for low side sensing or CPU power. The device uses a single 3 to 5.5 v supply with a maximum current of 1 mA. Supervisor INA220AIDGSR operates from -40°C to 125°C

While the INA220 can be read at any time and data from the last conversion is still available, conversion-ready bits (status register, CNVR bits) are provided to help coordinate one-shot or triggered conversions. The conversion ready bit is set after all conversion, averaging and multiply operations are complete.

The conversion ready bit is cleared under any of the following conditions: • A write to the configuration register, except when the mode bit is configured to power down or ADC off (disabled) mode; • a read of the status register

8.3.1.1 Power measurement

Current and bus voltage are converted at different points in time depending on the resolution and averaging mode settings. For example, when configured as an average of 12 bits and 128 samples, the time interval between sampling these two values can reach 68 ms. Again, these calculations are performed in the background and do not add to the overall conversion time.

8.3.1.2 PGA functions

If a larger full-scale shunt voltage is required, the INA220 provides PGA functionality that increases the full-scale range by a factor of 2, 4, or 8 (320 mV). Additionally, there are two full scales for bus voltage measurement: 16 or 32 volts.

8.3.1.3 Compatibility with TI Hot Swap Controllers

The supervisor INA220AIDGSR is designed to be compatible with hot swap controllers such as the TI TPS2490. The TPS2490 uses a high-side shunt, limited to 50 mV; the INA220 is 40 mV full scale, and the same shunt can be used to sense currents below this limit. When sensing at (or through) the TPS2490's 50 mv sense point is required, the INA220's PGA can be set to /2 to provide a full scale of 80 mv.