Transmitter charging module for light detection and ranging (lidar) device
Example embodiments relate to transmitter charging modules for light detection and ranging (lidar) devices. An example embodiment includes a method. The method includes receiving, from a controller, an indication of a first set of light emitters to be fired during a firing cycle. The first set of light emitters is a subset of a plurality of light emitters of the lidar device. The method also includes selectively charging, by a charging circuit of the lidar device during a charging cycle, a first set of energy storage devices of the lidar device. Additionally, the method includes refraining from charging, by the charging circuit of the lidar device during the charging cycle, each energy storage device in the plurality of energy storage devices that is not in the first set of energy storage devices. Further, the method includes emitting light signals from the first set of light emitters during the firing cycle.
1 . A method comprising:
receiving, from a controller of a light detection and ranging (lidar) device, an indication of a first set of light emitters to be fired during a firing cycle, wherein the first set of light emitters is a subset of a plurality of light emitters of the lidar device such that the plurality of light emitters includes one or more light emitters that are not in the first set of light emitters;
selectively charging, by a charging circuit of the lidar device during a charging cycle, a first set of energy storage devices of the lidar device, wherein the first set of energy storage devices is a subset of a plurality of energy storage devices of the lidar device such that the plurality of energy storage devices includes one or more energy storage devices that are not in the first set of energy storage devices, wherein each energy storage device of the first set of energy storage devices is associated with a light emitter in the first set of light emitters, wherein the charging circuit is arranged across a first printed circuit board (PCB) surface and a second PCB surface, wherein the first PCB surface and the second PCB surface are different surfaces of a single PCB, wherein the first PCB surface is located within a recession formed within the single PCB, and wherein the second PCB surface is located outside of the recession formed within the single PCB;
refraining from charging, by the charging circuit of the lidar device during the charging cycle, each energy storage device in the plurality of energy storage devices that is not in the first set of energy storage devices; and
emitting light signals from the first set of light emitters during the firing cycle, wherein emitting light signals from the first set of light emitters during the firing cycle comprises discharging, by a pulser circuit, energy stored within each of the energy storage devices in the first set of energy storage devices through the associated light emitter in the first set of light emitters.
2 . The method of claim 1 , wherein the indication of the first set of light emitters to be fired during the first firing cycle is received from the controller of the lidar device at a serial peripheral interface (SPI) of the charging circuit.
3 . The method of claim 1 , wherein the indication of the first set of light emitters to be fired during the firing cycle is received from the controller of the lidar device by a processor of the charging circuit.
4 . The method of claim 3 , wherein the processor of the charging circuit comprises a field-programmable gate array (FPGA).
5 . The method of claim 1 , wherein the lidar device comprises an application-specific integrated circuit (ASIC), and wherein the charging circuit is a component of the ASIC.
6 . The method of claim 1 , wherein the recession formed within the single PCB is a cavity.
7 . The method of claim 1 , wherein the recession formed within the single PCB is defined within the single PCB using additive or subtractive technologies.
8 . The method of claim 1 , wherein the first set of light emitters is arranged on the second PCB surface.
9 . The method of claim 1 , wherein components of the charging circuit are electrically interconnected between the first PCB surface and the second PCB surface using wirebonds on the first PCB surface or the second PCB surface and vias through the single PCB.
10 . The method of claim 1 , wherein the first PCB surface is approximately parallel with the second PCB surface.
11 . The method of claim 1 , wherein components of the charging circuit are electrically interconnected between the first PCB surface and the second PCB surface using soldered connections.
12 . The method of claim 1 , wherein the second PCB surface has a greater surface area than the first PCB surface.
13 . The method of claim 1 , wherein the plurality of light emitters comprises a group of four light emitters, wherein the plurality of energy storage devices comprises a group of four energy storage devices, and wherein selectively charging the first set of energy storage devices and refraining from charging each energy storage device in the plurality of energy storage devices that is not in the first set of energy storage devices comprises:
supplying, when the indication of the first set of light emitters to be fired during the firing cycle includes at least one light emitter in the group of four light emitters, a sufficient voltage to charge each of the energy storage devices in the group of four energy storage devices at respective nodes within the charging circuit that are associated with each of the energy storage devices in the group of four energy storage devices; and
deactivating, if one or more light emitters in the group of four light emitters are not included in the indication of the first set of light emitters to be fired during the firing cycle, the one or more respective nodes associated with the one or more light emitters in the group of four light emitters that are not included in the indication of the first set of light emitters to be fired during the firing cycle, wherein the deactivation of each respective node is performed by a respective switching component of the charging circuit.
14 . The method of claim 1 , wherein selectively charging the first set of energy storage devices and refraining from charging each energy storage device in the plurality of energy storage devices that is not in the first set of energy storage devices comprises:
supplying a sufficient voltage to charge each of the energy storage devices in the first set of energy storage devices at respective nodes within the charging circuit that are associated with each of the energy storage devices, wherein supplying the sufficient voltage to the respective nodes comprises connecting each of the respective nodes to a respective voltage supply using a respective switching component of the charging circuit; and
refraining from supplying the sufficient voltage to charge each of the energy storage devices that is not in the first set of energy storage devices at respective nodes within the charging circuit that are associated with each of the energy storage devices, wherein refraining from supplying the sufficient voltage to the respective nodes comprises disconnecting each of the respective nodes from a respective voltage supply using a respective switching component of the charging circuit.
15 . The method of claim 14 , wherein the charging circuit comprises an array of high-side switches, and wherein each of the respective switching components is a component of the array of high-side switches.
16 . The method of claim 15 , wherein the array of high-side switches is a component of a serial-controlled solenoid driver.
17 . The method of claim 1 , wherein at least one of the plurality of energy storage devices of the lidar device comprises a capacitor fabricated from silicon.
18 . The method of claim 1 , wherein the pulser circuit comprises one or more gallium nitride field-effect transistors (GaNFETs), and wherein the plurality of light emitters comprises one or more laser diodes.
19 . A light detection and ranging (lidar) device comprising:
a controller;
a plurality of light emitters;
a charging circuit comprising a plurality of energy storage devices; and
a pulser circuit,
wherein the charging circuit is configured to receive an indication of a first set of light emitters to be fired during a firing cycle, wherein the first set of light emitters is a subset of the plurality of light emitters such that the plurality of light emitters includes one or more light emitters that are not in the first set of light emitters,
wherein the charging circuit is configured to selectively charge, during a charging cycle, a first set of energy storage devices, wherein the first set of energy storage devices is a subset of the plurality of energy storage devices such that the plurality of energy storage devices includes one or more energy storage devices that are not in the first set of energy storage devices,
wherein each energy storage device of the first set of energy storage devices is associated with a light emitter in the first set of light emitters,
wherein the charging circuit is arranged across a first printed circuit board (PCB surface and a second PCB surface,
wherein the first PCB surface and the second PCB surface are different surfaces of a single PCB,
wherein the first PCB surface is located within a recession formed within the single PCB,
wherein the second PCB surface is located outside of the recession formed within the single PCB,
wherein the charging circuit is configured to refrain from charging, during the charging cycle, each energy storage device in the plurality of energy storage devices that is not in the first set of energy storage devices, and
wherein the pulser circuit is configured to discharge energy stored within each of the energy storage devices in the first set of energy storage devices through the associated light emitter in the first set of light emitters in order to cause the first set of light emitters to emit light signals during the firing cycle.
20 . A light detection and ranging (lidar) device comprising:
a controller;
a plurality of light emitters;
a charging circuit comprising a plurality of energy storage devices;
a pulser circuit,
wherein the charging circuit is configured to receive an indication of a first set of light emitters to be fired during a firing cycle, wherein the first set of light emitters is a subset of the plurality of light emitters such that the plurality of light emitters includes one or more light emitters that are not in the first set of light emitters,
wherein the charging circuit is configured to selectively charge, during a charging cycle, a first set of energy storage devices, wherein the first set of energy storage devices is a subset of the plurality of energy storage devices such that the plurality of energy storage devices includes one or more energy storage devices that are not in the first set of energy storage devices,
wherein each energy storage device of the first set of energy storage devices is associated with a light emitter in the first set of light emitters,
wherein the charging circuit is arranged across a first printed circuit board (PCB) surface and a second PCB surface,
wherein the first PCB surface and the second PCB surface are different surfaces of a single PCB,
wherein the first PCB surface is located within a recession formed within the single PCB,
wherein the second PCB surface is located outside of the recession formed within the single PCB,
wherein the charging circuit is configured to refrain from charging, during the charging cycle, each energy storage device in the plurality of energy storage devices that is not in the first set of energy storage devices, and
wherein the pulser circuit is configured to discharge energy stored within each of the energy storage devices in the first set of energy storage devices through the associated light emitter in the first set of light emitters in order to cause the first set of light emitters to emit light signals during the firing cycle; and
a plurality of light detectors configured to detect reflections of the light signals emitted by the first set of light emitters during the firing cycle.