Strange ST microcontroller LI1916 - Page 1
Forum section: electronics / general

author: Vtech
author_rank: Regular Contributor
timestamp: December 10, 2021, 08:49:35 am
content: I've found a strange, unknown ST part.I am pretty sure it is some kind of a microcontroller but the internet knows nothing about this chip. It is labeled LI1916 and has QFN20 rectangular package (6x4 pins). It is used in emergency lighting lamp.Does anyone have any idea what might it be?

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 10, 2021, 05:49:11 pm
content: It can be found through some brokers, like:https://mg.ic-components.com/products/LI1916.jsporhttps://www.ariat-tech.it/parts/ST/LI1916Couldn't find any datasheet though and nothing about it on ST's website.

author: Venturi962
author_rank: Regular Contributor
timestamp: December 10, 2021, 05:53:42 pm
content: Part of the ST7 Lite Series?Datasheet has 20Pin QFN:https://media.digikey.com/pdf/Data%20Sheets/ST%20Microelectronics%20PDFS/ST7LITE3xF2_Rev_9.pdfLikely not (Page 163 disagrees with part number)

author: Vtech
author_rank: Regular Contributor
timestamp: December 10, 2021, 06:16:01 pm
content: Quote from: Venturi962 on December 10, 2021, 05:53:42 pmYou may be onto something. Power supply pins agree with this ST7LITE. Possibly, reset pin also fits. Unfortunately, pins marked as OSC1 and 2 are used as GPIO in the application and in the datasheet there is no GPIO functionality on this pins.One more info. The product design dates back to 2007 so this may be quite an old chip but still manufactured (at least in 2016 when the lamp was manufactured).

author: Venturi962
author_rank: Regular Contributor
timestamp: December 10, 2021, 06:54:18 pm
content: Here is different variant without external clock on the block diagram but no pinout of the QFNhttps://pdf1.alldatasheet.com/datasheet-pdf/view/171533/STMICROELECTRONICS/ST7LITE0X/+05Q5W5VPSLpETSpPKIbaZZTOfqgjxdbo/1lQ+/datasheet.pdfDoes the board have a crystal?

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 10, 2021, 09:24:53 pm
content: I'm curious about this chip too, but even if we can find documentation it might not make commercial sense to use it, compared to something likean STM32G030 at 62¢. ST seem to have put the ST7 on the cash cow milking stand.

author: Vtech
author_rank: Regular Contributor
timestamp: December 10, 2021, 09:41:17 pm
content: Quote from: I wanted a rude username on December 10, 2021, 09:24:53 pmIt definitely won't make sense to use this chip (especially since it is unobtanium). I'm just curious what the heck is it.Btw. Good luck getting STM32G030 for 62c (or for any price actually) these days. STM32's are either unavailable or ludicrously expensive. I've even dusted off some old STM8 chips to use for simple projects and I'm currently looking into those Padauk 3 cent micros that I've bought just for fun years ago (when Dave put his famous video).

author: Vtech
author_rank: Regular Contributor
timestamp: December 10, 2021, 09:44:19 pm
content: Quote from: Venturi962 on December 10, 2021, 06:54:18 pm3rd try - my replies keep disappearing for some reason.There is no crystal on the board. Only IOs and ADCs are used.

author: Vtech
author_rank: Regular Contributor
timestamp: December 10, 2021, 09:48:03 pm
content: The board with bodged LDO (by me).

author: Vtech
author_rank: Regular Contributor
timestamp: December 10, 2021, 10:40:16 pm
content: I think I've found it (or at least I'm very close):https://www.avnet.com/shop/emea/products/stmicroelectronics/st7fli19bf1u6tr-3074457345629719766/Pins match application and part number is very close to the markings on the chip - ST7FLI19BF1U6TR can be abbreviated LI1916 on QFN package.Thanks Venturi962 for pointing me in the right direction.

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 10, 2021, 11:44:43 pm
content: Quote from: Vtech on December 10, 2021, 09:41:17 pmCurrently, it's available in large quantities on Digikey, but only in one package (SSOP): STM32G030F6P6And sure not at this price, unless you go for very large quantities. But it's still cheap.

author: Vtech
author_rank: Regular Contributor
timestamp: December 10, 2021, 11:51:45 pm
content: Quote from: SiliconWizard on December 10, 2021, 11:44:43 pmNearly 2$ a piece. Not exactly cheap. I used to buy STM32F030F6 for 70c in small quantities. I like G series but in QFN packages (there is a version without central pad which helps a lot with routing).

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: December 11, 2021, 10:47:10 pm
content: Quote from: Vtech on December 10, 2021, 09:41:17 pmIs 93,869 units in stock enough for you?If not, maybe contact ST directly.The G series has been impacted way less because it's new and not pin-compatible with F and L. There are still shortages of the QFNs you prefer from almost all vendors though, due to bottlenecks in the packaging step.

author: Vtech
author_rank: Regular Contributor
timestamp: December 11, 2021, 10:58:59 pm
content: Quote from: I wanted a rude username on December 11, 2021, 10:47:10 pmGood to know.Were they restocked recently? I've checked not long ago on LCSC and most of stm's were gone or had ludicrous price. I was looking for some small QFN Stm32 just a week ago.Still, there are over 2000 variants of Stm32 on LCSC but only less than 80 are actually available (most of them are G series).Edit: Oh, one more thing. Have you seen the prices for some of the chips?STM32F103C8 for 10$! Ten bucks for this basic chip!STM32F429 for 70$LCSC was always a bit expensive as a source of STM's but current prices are either hilarious or terrifying depending on how you look at it.I need STM32G474 for current production and it's nowhere to be found.