US 11,728,621 B2
Voltage controlled steered VCSEL driver
John Kevin Moore, Edinburgh (GB)
Assigned to STMicroelectronics (Research & Development) Limited, Marlow (GB)
Filed by STMicroelectronics (Research & Development) Limited, Marlow (GB)
Filed on Jun. 3, 2020, as Appl. No. 16/891,936.
Claims priority of provisional application 62/857,710, filed on Jun. 5, 2019.
Prior Publication US 2020/0388987 A1, Dec. 10, 2020
Int. Cl. H01S 5/042 (2006.01); H01S 5/068 (2006.01); H01S 5/42 (2006.01)
CPC H01S 5/0427 (2013.01) [H01S 5/06808 (2013.01); H01S 5/423 (2013.01)] 35 Claims
OG exemplary drawing
 
1. A time of flight ranging system, comprising:
a plurality of laser emitters each configured to, when activated by a laser drive signal, emit laser photons;
a laser driver configured to generate the laser drive signal based upon a feedback control signal;
a steering circuit configured to selectively steer the laser drive signal to a different selected one of the plurality of laser emitters and prevent the laser drive signal from being steered to non-selected ones of the plurality of laser emitters, during each time period of a plurality of time periods;
control circuitry configured to sense a magnitude of a current of the laser drive signal and to generate the feedback control signal based thereupon, the feedback control signal being generated so as to cause the laser driver to generate the laser drive signal as having a current with a substantially constant magnitude;
a photon detection circuit configured to detect those of the laser photons that have reflected off an object within a field of view of the selected one of the plurality of laser emitters; and
processing circuitry configured to determine a distance to the object based upon an elapsed time between emission of the laser photons and detection of the laser photons after reflection off the object.