Current and Power Monitor with I2C Interface - TI INA209

Texas Instruments introduced the INA209 current and power monitor IC with an I2C interface. INA209 enables monitoring and control of voltage, current,  and power in a variety of applications such as automotive, telecom equipment, servers, battery chargers, test equipment, and power management. Utilizing a zero-drift, auto-zeroing architecture, the INA209 provides a high accuracy current sensing solution that offers 1% maximum accuracy (within - 40C to +85C), with 100uV maximum offset.

Features of INA209 current and power monitor:

• SENSES BUS VOLTAGES FROM 0V TO +26V
• HIGH ACCURACY: 1% MAX OVER TEMP
• REPORTS CURRENT, VOLTAGE, AND POWER; STORES PEAKS
• TRIPLE WATCHDOG LIMITS:
  • Lower Warning with Delay
  • Upper Over-limit, No Delay
  • Fast Analog Critical
• APPLICATIONS
  • SERVERS
  • TELECOM EQUIPMENT
  • AUTOMOTIVE
  • POWER MANAGEMENT
  • BATTERY CHARGERS
  • WELDING EQUIPMENT
  • POWER SUPPLIES
  • TEST EQUIPMENT

The INA209 monitors the drop across a shunt resistor and senses shunt bus voltage from 0V to +26V. An internal multiplier and calibration register provide direct data for current in amps and power in watts. The device operates from a single +3.0 to +5.5 supply.

The INA209 current and power monitor IC  features three levels of programmable watchdogs. The lowest level includes a programmable delay to ignore transient events. An intermediate level provides an output with no delay. A fully programmable fast analog path enables the highest level of warning for use in implementing immediate system shutdowns. In addition to the internal filtering for current and voltage measurements, the fast analog comparator also includes a filter for use in noisy environments.

Full scale readings as low as +/-40mV are available, keeping shunt dissipation to a minimum while a programmable gain amplifier function provides additional higher ranges. The ADC converts 12-bit values in 530us, and offers combinations of lower resolution with higher speed as well as averaging (up to 128 samples). An external trigger line is available to trigger conversions at specific times.

The I2C interface includes a timeout to prevent bus lock-up and a high speed mode to enable communications up to 3.4MHz. All features of the INA209 are software programmable.

The INA209 current and power monitor IC is shipped in a TSSOP-16 package with price starts at $3.50 in 1K unit qty.

Texas Instruments INA209 - Current and Power Monitor with I2C Interface