Is there any IC for solar powered LED lighting ? - Page 1
Forum section: electronics / general

author: BravoV
author_rank: Super Contributor
timestamp: September 24, 2020, 07:34:37 am
content: I imagine that the chip has built-in all major functions, like DC converter for battery (Li-Ion) charging & management, and also for powering the LED from the battery. And I expect probably it needs only minimal count of external components, probably only discrete ones say like for timing, sensor and power components (inductor, mosfet etc).Very typical application used in solar powered lighting for outdoor I guess.Any hint,suggestion or direction on where to get one, will be appreciated, TIA.

author: tszaboo
author_rank: Super Contributor
timestamp: September 24, 2020, 09:50:36 am
content: Bigclive took apart a bunch of these and reverse engineered them. I would watch some of his Youtube videos.

author: calmtron
author_rank: Regular Contributor
timestamp: September 24, 2020, 10:12:21 am
content: XY8018

author: BravoV
author_rank: Super Contributor
timestamp: September 25, 2020, 02:19:19 am
content: Quote from: calmtron on September 24, 2020, 10:12:21 amThanks, but I think its probably not suitable for street light, maybe more for toy or really small stuff, what I'm looking for is smart chip that capable of delivering 5 to 50 Watt lighting.Still looking.

author: ogden
author_rank: Super Contributor
timestamp: September 25, 2020, 04:28:13 am
content: Check TI appnotes likeTIDA-00121to see that simple solar LED street light chip with all built-in functions can't exist. Battery charger needs power transistor + diode + inductor, LED driver needs power transistor + diode + inductor. All that needs some controller with brains, thus MCU with ADC - especially when you have options of power and battery capacity range.

author: BravoV
author_rank: Super Contributor
timestamp: September 25, 2020, 04:39:48 am
content: Thanks, its surprising no one ever design and build it, a single ASIC that handle the smart aspect, while only need external components such as for power (mosfets,inductor, caps) and maybe sensor.I guess I was naively thought the solar powered light such as for street light market is huge, millions ?

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 25, 2020, 04:48:55 am
content: Quote from: BravoV on September 25, 2020, 04:39:48 amThat part does exist, it's called a microcontroller...

author: BravoV
author_rank: Super Contributor
timestamp: September 25, 2020, 05:08:33 am
content: Quote from: NiHaoMike on September 25, 2020, 04:48:55 amMy fault, cause maybe I see this from business POV, maybe I'm wrong.

author: james_s
author_rank: Super Contributor
timestamp: September 25, 2020, 06:07:20 am
content: The vast majority of street lights are powered by the grid. A solar powered light seems like a niche market sort of thing, the cost per luminaire is going to be far higher than a conventional grid powered light and it is likely going to require more maintenance. If there is a stretch of multiple lights as is usually the case then it's likely more economical to have a central solar array and battery bank that controls multiple lights.

author: BravoV
author_rank: Super Contributor
timestamp: September 25, 2020, 06:13:46 am
content: Yeah, I guess I've set my expectation too high.

author: ogden
author_rank: Super Contributor
timestamp: September 25, 2020, 03:20:53 pm
content: Quote from: BravoV on September 25, 2020, 05:08:33 amReallyDesiging ASIC for low volume market does not sound like smart (business) decision. Solution for you would be to look for two part solution - battery charge controller + led driver, both controlled using low cost MCU.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 26, 2020, 02:06:16 am
content: Don't even need a dedicated switching controller, there are microcontrollers with PWM specifically designed for switching power supplies nowadays (as in hardware support for current mode control). By using a bidirectional buck/boost converter, you can have the power electronics do double duty for LED driving and MPPT. The solar panel can be selected to have a lower voltage than the forward drop of the LEDs so it can simply be connected in parallel with just a Schottky diode to prevent reverse current. A simple resistive divider to one of the microcontroller ADC pins allows the solar panel to double as a light sensor.All in all, even some pretty advanced functionality like PIR based dimming and inferring time of day using the light levels can be implemented in a low end PIC16 or equivalent.

author: ogden
author_rank: Super Contributor
timestamp: September 26, 2020, 05:57:27 pm
content: Quote from: NiHaoMike on September 26, 2020, 02:06:16 amYou forgot to mention those microcontrollers. Please be specific. I suggested controllers because that is kind of integrated solution as OP wanted. Using MCU means as "nonintegrated" as you can get.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 26, 2020, 07:07:56 pm
content: With built in gate drivers:https://www.microchip.com/design-centers/power-management/dc-dc-controllers/digitally-enhanced-power-analog-hybrid-controllersWithout built in gate drivers:https://www.microchip.com/design-centers/intelligent-power/core-independent-peripheral-hybrid-power-controllers

author: ogden
author_rank: Super Contributor
timestamp: September 26, 2020, 08:15:50 pm
content: Quote from: NiHaoMike on September 26, 2020, 07:07:56 pmThanx! Very interesting. Thou could you elaborate how mentioned MCU can be used for both - MPPT battery controller and LED driver? It seems like single channel/function controller.

author: NiHaoMike
author_rank: Super Contributor
timestamp: September 27, 2020, 12:58:37 am
content: Quote from: ogden on September 26, 2020, 08:15:50 pmYou're only using it for a LED driver or MPPT controller one at a time, not both at once. Therefore, with careful selection of solar panel and LED array voltages, the same controller will handle both without any extra switching. The software handles reconfiguration for both modes.

author: David Hess
author_rank: Super Contributor
timestamp: September 28, 2020, 03:49:41 pm
content: Look for an "energy harvesting" IC like the LTC3105.