24-bit, 3-channel ECG analog front end cuts power consumption by 85 percent compared with alternative integrated solutions

November 29, 2012 // By Paul Buckley
Texas Instruments Incorporated has expanded the company’s ADS1298 analog-front-end (AFE) family with the industry's most power-efficient 24-bit, 3-channel AFE for biopotential measurement applications, such as portable, battery-powered electrocardiogram (ECG) solutions, Holter monitors and wireless patient monitoring equipment.

The ADS1293 is also the first device in the family that can support one to five leads with a single AFE to reduce the size, power consumption and overall cost of scalable medical instrumentation systems. Each channel of the ADS1293 can be independently programmed for a specific sample rate and bandwidth, allowing customers to optimize the configuration for performance and power.

In addition to the ADS1293, the company unveiled WEBENCH Medical AFE Designer, the latest addition to TI's growing family of WEBENCH design tools. WEBENCH Medical AFE Designer simplifies and speeds system design with the ADS1293, enabling customers to design and configure the AFE online. They can then download configuration data to the ADS1293 evaluation module (EVM), reducing design time from weeks or months to a matter of minutes.

The ADS1293 consumes only 300 uW per channel, 85-percent less than alternative integrated solutions and includes simultaneous digital ECG and pace signals on each channel to eliminate the need for a dedicated pace channel, which reduces power consumption.

The device also includes comprehensive built-in error detection with an alarm pin, relieving the controller from continuously polling for error conditions which allows independent shutdown on any functional blocks that are not in use.

The ADS1293 is highly integrated to simplify design, reduce board space which optimizes signal path gain stages to eliminate the need for analog filters and reduces board space requirements by integrating three 24-bit delta sigma analog-to-digital converters (ADCs), four low-noise instrumentation amplifiers and EMI-hardened inputs, right leg drive amplifier, lead-off detection, and Wilson and Goldberger terminals.

The ADS1293EVM can be purchased today for $99. This evaluation module's development tool provides a user-friendly graphical user interface (GUI) with an interactive block diagram, which allows designers to try different system configurations with the chip quickly and easily. ECG and pace data can also be captured and saved for post processing. The ADS1293 development tool is also available online in the WEBENCH