TI Introduces Bi-Directional Current, Voltage and Power Monitor with I²C Interface
Texas Instruments Inc. (TI) introduced a high-side measurement, bi-directional current/power monitor integrated circuit (IC) with an I²C interface. Utilizing a zero-drift, auto-zeroing architecture, the INA209 is claimed to provide a high accuracy current sensing solution that offers 1% maximum accuracy over the -40 to +85°C temperature range, with 100uV maximum offset. The device enables monitoring and control of current, voltage and power in a variety of applications such as servers, telecom equipment, battery chargers, power management, automotive and test equipment.
The INA209 monitors the drop across a shunt resistor and senses shunt bus voltage from 0 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 device 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 is available now in a TSSOP-16 package. The device is priced at $3.50 in 1,000 piece quantities (suggested resale pricing).
