Maxim improves infra-red gesture chip

Author: EIS Release Date: Jul 6, 2021

Maxim has created a lensed version of its MAX25205 optical gesture sensor to increase sensitivity and signal to noise ratio.

 

max25405

The result is the MAX25405 and, like its predecessor, it is intended to displace camera-based time-of-flight systems in automotive, industrial and consumer gesture recognition.

 

“MAX25405 senses a wider proximity of movement and doubles the sensing range from 20cm to 40cm when compared to earlier infra-red generations,” according to the company (see table below).

 

 

max25405 gesture block Like the earlier MAX25205, this chip includes a 6 x 10 array of infra-red photodiodes for reception, addressable from a host microcontroller over SPI or I2C.

 

Via external transistors it can also switch the necessary external infra-red LEDs – duty cycle is programmable from 1/16 to 16/16.

 

Gesture recognition is off-chip, by an algorithm in the host MCU (Cortex M0 in a MAX32630 is suggested), where nine gestures can be picked-out including swipe, rotation, air-click, linger-to-click and six proximity zones.

 

MAX25205 MAX25405

left-right gesture 20cm 40cm

up-down gesture 20cm 40cm

rotation gesture 15cm 30cm

Proximity 3×2 zones 3×2 zones

field of view >±20° >±30°

Applications are foreseen in automotive, industrial and consumer products – touch-free smart hubs and thermostats are examples of the latter.

 

“Gesture sensing adds value to low- and mid-range cars, while offering passengers the luxury of touch-free gesture control,” Maxim business unit director Szu-Kang Hsien.

 

Packaging is 4 x 4 x 1.35mm 20pin QFN package, and there is an evaluation kit: MAX25405EVKIT#.