Electronic Components Datasheet Search |
|
SI1120 Datasheet(PDF) 6 Page - Silicon Laboratories |
|
SI1120 Datasheet(HTML) 6 Page - Silicon Laboratories |
6 / 20 page Si1120 6 Rev. 1.0 2. Application Information 2.1. Theory of Operation The Si1120 is an active optical-reflectance proximity detector and ambient-light sensor with a pulse-width modulated output. Depending on the mode selected, the duration of the PRX active (low) state is proportional to the amount of reflected light, the amount of zero-reflectance offset, or the amount of ambient light. The detection rate can be set by adjusting the frequency of the STX signal. The dual-port, active reflection proximity detector has significant advantages over single-port, motion-based infrared systems, which are good only for triggered events. Motion detection only identifies proximate moving objects and is ambiguous about stationary objects. The Si1120 allows in- or out-of-proximity detection, reliably determining if an object has left the proximity field or is still in the field even when it is not moving. An example of a proximity detection application is controlling the display and speaker of a cellular telephone. In this type of application, the cell phone turns off the power-consuming display and disables the loudspeaker when the device is next to the ear, then reenables the display (and, optionally, the loudspeaker) when the phone moves more than a few inches away from the ear. For small objects, the drop in reflectance is as much as the fourth power of the distance; this means that there is less range ambiguity than with passive motion-based devices. For example, a sixteen-fold change in an object's reflectance means only a fifty-percent drop in detection range. The Si1120 periodically measures proximity at a rate that can be set by an external controller. The Si1120 modes are: PRX400 Proximity, 400 mA LED current PRX50 Proximity, 50 mA LED current PRX50H Proximity, 50 mA LED current, high reflectance range OFC Offset calibration (proximity mode, no LED current) VAMB Visible ambient (10 klux sunlight) VIRL Visible and infrared ambient light, low range (500 lux sunlight) VIRH Visible and infrared ambient light, high range (128 klux sunlight) |
Similar Part No. - SI1120_10 |
|
Similar Description - SI1120_10 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |