The INA209 is a high-side current shunt and power monitor with an I2C interface. The INA209 monitors both shunt drop and shunt bus voltage. A programmable calibration value, combined with an internal multiplier, enables direct readouts in amperes. An additional multiplying register calculates power in watts. The INA209 features two separate, onboard watchdog capabilities: a warning comparator and an over-limit comparator. The warning comparator is useful for monitoring lower warning limits and incorporates a user-defined delay. The over-limit comparator assists with monitoring upper limits that could require immediate system shutdown.
The INA209 also includes an analog comparator and a programmable digital-to-analog converter (DAC) that combine to provide the fastest possible responses to current overload conditions.
The INA209 can be used together with hot swap controllers that already use a current sense resistor. The INA209 full-scale range can be selected to be either within the hot-swap controller sense limits, or wide enough to include them.
The INA209 senses across shunts on buses that can vary from 0V to 26V. The device uses a single +3V to +5.5V supply, drawing a maximum of 1.5mA of supply current. It is specified for operation from -25°C to +85°C.