Current, Voltage, Power Monitor features I²C interface.

Press Release Summary:

Model INA209 high-side measurement, bi-directional current/power monitor IC offers 1% accuracy over -40 to +85°C temperature range with 100 µV maximum offset. Enabling monitoring and control of current, voltage, and power, device monitors drop across shunt resistor, senses shunt bus voltage from 0-26 V, and offers full scale readings as low as ±40 mV. I²C interface includes timeout to prevent bus lock-up and high speed mode to enable communications up to 3.4 MHz.

Original Press Release:

TI Introduces Bi-Directional Current, Voltage and Power Monitor with I²C Interface

Device Provides High Accuracy for Power Monitoring and Control in Servers, Telecom and Industrial Equipment

DALLAS (July 5, 2007) - Texas Instruments Incorporated (TI) (NYSE: TXN) today 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 provides a high accuracy current sensing solution that offers one percent maximum accuracy over the -40C to +85C 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. (See

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 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.

Available Today

The INA209 is available now in a TSSOP-16 package from TI and its authorized distributors. The device is priced at $3.50 in 1,000 piece quantities (suggested resale pricing).

TI offers analog engineers a wide-ranging support infrastructure that includes training and seminars, design tools and utilities, technical documentation, evaluation modules, an online KnowledgeBase, a product information hotline and a comprehensive offering of samples that ship within 24 hours of request. To download the latest Amplifier and Data Converter Selection Guide or for more information on TI´s complete analog design support, visit

Texas Instruments Incorporated provides innovative DSP and analog technologies to meet our customers' real world signal processing requirements. In addition to Semiconductor, the company includes the Education Technology business. TI is headquartered in Dallas, Texas, and has manufacturing, design or sales operations in more than 25 countries.

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