Ams Launches AS705x Analog Front End Series

     Ams announced the launch of its first pure integrated circuit vital signs sensor series, AS705x. The first generation of biosignal conversion device of Ams provides manufacturers with great flexibility. The highly customized optical front end, combined with energy-saving design and compact shape, is very suitable for applications with limited circuit board space, such as listening devices, smart watches or smart patches.

     AS7050 is the first biosignal sensor in Ams new product series, which enables end users to capture biological signals such as heart rate measurement (HRM) and skin resistance (GSR). With the help of two ADC channels and an embedded ECG low-noise analog front-end, the AS7050 can simultaneously measure the optical plethysmography (PPG) and electrocardiogram (ECG). Customers who need smaller optical devices and do not need ECG can choose AS7056 or AS7057 series products.

     Dr. Markus Arzberger, Head of AMS Vital Sign Monitoring Application Business Department, said: "AS7056 and AS7057 are the smallest AFEs on the market for vital sign monitoring, with a chip size of about 1.7 mm x 1.7 mm. Ams new biosensors can be used for PPG based hearing devices or accessories to measure vital signs. These two products enable customers to combine advanced analog-to-digital conversion processes to develop tiny, highly customized optical front ends."

     The optical system can be used for non-invasive measurement of vital signs such as heart rate variability. PPG (photoelectric plethysmography) is the most common optical system solution, which can be used for heart rate measurement. Green light shines into body tissues, which are scattered and partially absorbed by blood. A small part of the emitted light is scattered back to the photodiode and detected with an integrated circuit. Since blood volume changes with heart rate, light absorption and photodiode signal are correspondingly modulated by heart rate.

     The AS7050 provides up to 8 LED driver outputs, can sample up to 6 photodiode inputs, and supports external electrodes. The AS7056 and AS7057 can support up to three photodiodes and three emitters, and one of the emitters of the AS7056 is a VCSEL (Vertical Resonant Cavity Surface Emitting Laser) driver. This provides high flexibility for various transmitter and photodiode settings in different applications.

     In daily life, as consumers use smart watches, listening devices and other devices to monitor vital signs, manufacturers are trying to reduce the complexity of products and improve user experience by reducing power consumption and improving design. In addition to AFE, if the developers of vital sign monitoring applications need to adopt space saving design, they can also obtain all building blocks required for the entire system from Ams, such as transmitters and detectors.