Application US20190341918

ARRANGEMENT FOR A PHOTODETECTOR CIRCUIT FOR LOW POWER APPLICATIONS, AND A CORRESPONDING METHOD AND A COMPUTER PROGRAM PRODUCT
[+] Show Details

US20190341918

1. An arrangement for controlling performance of a photodetector in an electronic circuit, where the photodetector is configured to be sensitive to light, the arrangement comprising: (6) (6)

a positive supply voltage (V_cc) port and a ground (GND) port where the photodetector is connected in the electronic circuit between these ports directly or indirectly,

the photodetector is connected via a main resistor (R_L) to the positive supply voltage (V_cc) port or to the ground (GND) port, wherein the arrangement further comprises

an external bias resistor (R_L2) to be connectable in parallel to the main resistor (R_L),

a microcontroller which is configured to switch on at least one resistor (R_L, R_L2) at a time by an output signal of the microcontroller,

so that when the electronic circuit is configured to be switched on, the microcontroller connects the external bias resistor (R_L2) on between the photodetector and the positive supply voltage (V_cc) port, or between the photodetector and the ground (GND) port, for a time period enabling a bias to set for the photodetector, and

when the bias has been set, the microcontroller is configured to disconnect functionally the external bias resistor (R_L2) from the electronic circuit.

2. The arrangement according to claim 1, wherein the photodetector is a phototransistor (Q), where its base (B) is sensitive to light. (2) (0)

5. The arrangement according to claim 1, wherein the microcontroller is configured to activate at least one of the resistors through direct output voltages, or via a respective switch (S1, S2) connected in series with the respective resistor (R_L, R_L2). (0)

7. The arrangement according to claim 1, wherein the electric circuit applies one or more further external bias resistors (R_L3, R_L4) connected in parallel with the external bias resistor (R_L2) and the main resistor (R_L). (1) (0)

10. The arrangement according to claim 1, wherein the time period between the connecting and disconnecting instants is selected to be between 2-20 microseconds. (0)

11. The arrangement according to claim 1, wherein the resistance of the main resistor (R_L) is 1-4 kΩ. (0)

12. The arrangement according to claim 1, wherein the resistance of the external bias resistor (R_L2) is 100-400Ω. (0)

13. A method for controlling performance of a photodetector in an electronic circuit, where the photodetector is configured to be sensitive to light, the method comprising the steps of: (0) (6)

connecting the photodetector in the electronic circuit between a positive supply voltage (V_cc) port and a ground (GND) port directly or indirectly,

connecting the photodetector via a main resistor (R_L) to the positive supply voltage (V_cc) port or to the ground (GND) port, wherein the method further comprises the steps of

connecting an external bias resistor (R_L2) in parallel to the main resistor (R_L),

switching on at least one resistor (R_L, R_L2) at a time by an output signal of a microcontroller,

when the bias has been set, disconnecting functionally the external bias resistor (R_L2) from the electronic circuit by the microcontroller.

14. A computer program product for controlling performance of a photodetector in an electronic circuit, where the photodetector is configured to be sensitive to light, wherein the computer program product comprises program code storable on a computer readable storage medium, the program code being configured to execute the following steps when the program code is run in a microcontroller or in an external processor: (0) (6)

connecting the photodetector in the electronic circuit between a positive supply voltage (V_cc) port and a ground (GND) port directly or indirectly,

connecting the photodetector via a main resistor (R_L) to the positive supply voltage (V_cc) port or to the ground (GND) port, wherein the program code is further configured to execute the following steps

connecting an external bias resistor (R_L2) in parallel to the main resistor (R_L),

switching on at least one resistor (R_L, R_L2) at a time by an output signal of the microcontroller,

when the bias has been set, disconnecting functionally the external bias resistor (R_L2) from the electronic circuit by the microcontroller.

View Abstract and Specification Size

PDF with Images and Document Face >

Full Text Publication >

Application US20190341918

ARRANGEMENT FOR A PHOTODETECTOR CIRCUIT FOR LOW POWER APPLICATIONS, AND A CORRESPONDING METHOD AND A COMPUTER PROGRAM PRODUCT

Patent Matrix® Search