MicroLED power considering outlier pixel dynamic resistance
Discussed herein are systems, devices, methods, and computer-readable media for reducing a number of undriven or underdriven uLEDs of a uLED die. A method can include identifying, by a controller of a micro light emitting diode (uLED) die, a dynamic series resistance (R d ) or forward voltage (V f ) of a uLED of the uLED die, selecting, by the controller and based on the identified R d or V f , a current level (I PWM_0 ) less than a maximum current level (I PWM_MAX ) supplied by a uLED driver coupled to the uLED die, and causing, by the controller, current, at the selected current level, to be supplied to the uLED driver.
1. A method comprising:
identifying, by a controller of a micro light emitting diode (uLED) die, a dynamic series resistance (R d ) or forward voltage (V f ) of a uLED of the uLED die;
selecting, by the controller and based on the identified R d or V f , a current level (I PWM_0 ) less than a maximum current level (I PWM_MAX ) supplied by a uLED driver coupled to the uLED die; and
causing, by the controller, an electrical current, at the selected current level, to be supplied to the uLED driver.
2. The method of claim 1 , further comprising increasing, by the controller, a pulse width modulation (PWM)-on time of the uLED in response to selecting I PWM_0 .
3. The method of claim 1 , further comprising testing, by test equipment, each uLED of the uLED die to determine whether the uLED includes R d or V f greater than a specified threshold.
4. The method of claim 3 , further comprising storing, in a memory accessible by a controller of the uLED die, data indicating an identification (ID) of each uLED of the uLED die that includes R d greater than the specified threshold.
5. The method of claim 4 , further comprising determining, based on the identified R d , I PWM_0 such that the V f of the uLED is less than (or equal to) a maximum supply voltage (V LED ).
6. The method of claim 3 , wherein the controller selects I PWM_0 for each uLED of the uLED die that includes R d or V f greater than the specified threshold.
7. The method of claim 3 , wherein the specified threshold is a specified percentile of R d or V f values across all uLEDs of the uLED die.
8. The method of claim 1 , wherein selecting the current level (I PWM_0 ) less than a maximum current level (I PWM_MAX ) supplied by a uLED driver coupled to the uLED die based on a difference between R d or V f of an outlier uLED and an average R d or V f of non-outlier uLEDs of the uLED die, the outlier uLED including an R d greater than a specified number of standard deviations greater than the average R d or V f of the uLEDs.
9. A system comprising:
a micro light emitting diode (uLED) die comprising uLEDs and respective uLED drivers;
a power supply coupled to the uLED die; and
a controller coupled to the uLED die, the controller to provide a control command and configured to:
identify, a dynamic series resistance (R d ) or forward voltage (V f ) of a uLED of the uLED die;
select, based on the identified R d or V f , a current level (I PWM_0 ) less than a maximum current level (I PWM_MAX ) supplied by a uLED driver of the uLED die; and
cause the power supply to provide an electrical current at the selected current level to the uLED driver.
10. The system of claim 9 , wherein the controller is further configured to increase a pulse width modulation (PWM)-on time of the uLED in response to selecting I PWM_0 .
11. The system of claim 9 , further comprising test equipment configured to test each uLED of the uLED die to determine whether the uLED includes R d or V f greater than a specified threshold.
12. The system of claim 11 , further comprising a memory accessible by the controller of the uLED die to store data indicating an identification (ID) of each uLED of the uLED die that includes R d greater than the specified threshold.
13. The system of claim 12 , wherein the controller is further configured to determine, based on the identified R d , I PWM_0 such that the V f of the uLED is less than (or equal to) a maximum supply voltage (V LED ).
14. The system of claim 11 , wherein the controller selects I PWM_0 for each uLED of the uLED die that includes R d or V f greater than the specified threshold.
15. A machine-readable medium including instructions that, when executed by a hardware-based processor, cause a machine to perform operations comprising:
identifying, by a controller, a dynamic series resistance (R d ) or forward voltage (V f ) of a micro light emitting diode (uLED) of a uLED die;
select, by the controller, based on the identified R d or V f , a current level (I PWM_0 ) less than a maximum current level (I PWM_MAX ) supplied by a uLED driver of the uLED die; and
cause, by the controller, a power supply to provide an electrical current at the selected current level to the uLED driver.
16. The machine-readable medium of claim 15 , wherein the operations further comprise increasing, by the controller, a pulse width modulation (PWM)-on time of the uLED in response to selecting I PWM_0 .
17. The machine-readable medium of claim 15 , wherein the operations further comprise testing, by test equipment, each uLED of the uLED die to determine whether the uLED includes R d or V f greater than a specified threshold.
18. The machine-readable medium of claim 17 , wherein the operations further comprise storing, in a memory, data indicating an identification (ID) of each uLED of the uLED die that includes R d greater than the specified threshold.
19. The machine-readable medium of claim 17 , wherein the specified threshold is a specified percentile of R d or V f values across all uLEDs of the uLED die.
20. The machine-readable medium of claim 15 , wherein selecting the current level (I PWM_0 ) less than a maximum current level (I PWM_MAX ) supplied by a uLED driver coupled to the uLED die based on a difference between R d or V f of an outlier uLED and an average R d or V f of non-outlier uLEDs of the uLED die, the outlier uLED including an R d greater than a specified number of standard deviations greater than the average R d or V f of the uLEDs.