Analog Devices has announced a MEMS accelerometer with the lowest power consumption, the ADXL362. The company cites the following levels as the lowest in the industry:
- Measurement current: 2 µA
- Wakeup mode: 300 µA
- Sleep current: 10 nA
The innovation that ADI has achieved is the design of the control circuit for the accelerometer. More intelligence and interrupt processing has been designed into the control logic. The MEMS sensor itself is also low power, but it was designed to fit the control circuit.
ADI has focused on the usage model for the accelerometer. This is not intended for portable consumer and smartphone applications which already have a cost effective solution. In these products consumers are accustomed to plugging in a device to recharge on a daily basis. ADI is targeting the ADXL362 at markets that require long battery life, on the order of years. These are applications that it is either costly and/or very difficult to change the battery. This includes monitoring remote or dangerous locations such as pipelines, bridges, tall buildings, etc. Other applications include sealed environments (military and medical monitoring), cattle tracking and gas meters.
The usage model ADI is working with for the ADXL362 is one in which prevents activity due to unintentional motion. The accelerometer acts as a power switch to wake up the whole system. The price is very competitive for an industrial application, $3.97 per 1 K unit. It is being sampled right now and available August 2012.
The ADI ADXL362 is addressing a growing market for remote sensors. Most of these are wireless and must depend on batteries. This device would be an important component in a Wireless Sensor Network (WSN) sensor node. Power savings for a WSN sensor node are achieved by using sleep mode and activating for a short period of time. There are just over 600,000 bridges in the United States alone, of which one in four is classified either structurally deficient or functionally obsolete. The average number of WSN sensor nodes required per bridge is 500. There is almost 2 million kilometers of oil and gas pipelines worldwide, with about 41% in the US. To properly monitor a pipeline a WSN sensor node needs to be deployed every 100 m. Thus, there is a large potential market for ADI.
Chief Technology Officer
Semico Research Corp.