TM1637 Interface with 3.3V Microcontroller  - Page 1
Forum section: electronics / general

author: jtronix
author_rank: Regular Contributor
timestamp: July 30, 2019, 06:09:58 am
content: Hi,I'm going to use TM1637 for 7 Segment Drive. When I checked the datasheet i found that chip support for 5V, and now a days in industries majority of the microcontroller is supplied by 3.3V.Just want to check can I use TM1637 with 3.3V microcontroller?Can SCK, DIO I2C work with 3.3V microcontroller?

author: lollandster
author_rank: Contributor
timestamp: July 30, 2019, 08:25:32 am
content: From what I can see the chip should work fine with 3.3V as long as the LEDs are red.Note that 3.3V on SCK and DIO will probably not work if VDD is 5V since the minimum logic high-level voltage is 0.7 x VDD.

author: jtronix
author_rank: Regular Contributor
timestamp: July 30, 2019, 08:55:31 am
content: In Datasheet Power Supply voltage typical rating is mention 5V but Min and Max rating is not mention..Have you used this chip at 3.3V??

author: ogden
author_rank: Super Contributor
timestamp: July 30, 2019, 09:10:55 am
content: Quote from: jtronix on July 30, 2019, 08:55:31 amMany hobbyists successfully use this chip at 3.3V because most of cheap 7-segment led display modules are based on TM1637. YouTube have more than one video telling how to use TM1637 with 3.3 MCU:https://www.youtube.com/results?search_query=TM1637++stm32

author: Dabbot
author_rank: Regular Contributor
timestamp: July 30, 2019, 09:26:29 am
content: Quote from: jtronix on July 30, 2019, 08:55:31 amThis module from Seeed Studio using the TM1637 specifies 3.3V as a minimum:https://www.mouser.com/ds/2/744/Seeed_104030003-1217744.pdf

author: jtronix
author_rank: Regular Contributor
timestamp: July 30, 2019, 09:54:13 am
content: If device is ok with 3.3V then i don;t know why chip manufacture has not mention?Is there any functional limitation while using with 3.3V?

author: Dabbot
author_rank: Regular Contributor
timestamp: July 30, 2019, 10:04:20 am
content: Apart from restricting its use to LEDs with a low voltage drop, as mentioned by lollandster, probably not.Only one way to find out.

author: ogden
author_rank: Super Contributor
timestamp: July 30, 2019, 10:20:09 am
content: Quote from: jtronix on July 30, 2019, 09:54:13 amIt's because each parameter of specification depends on many others, most important being VCC. Lack of 3.3V specification does not mean that chip at 3.3V do not work at all. As it is proven allover hobbyist reports, it does work. Problem with 3.3V could be that it does not meet timing specifications, cannot reach max specified output current or it does not work reliably at extreme temperature either -40 or +85℃. As far as you do not plan to manufacture thousands of products with assured quality, most likely you will be fine. Just try. It do not cost much and you will gain experience even if it fails for your (unspecified) application

author: jtronix
author_rank: Regular Contributor
timestamp: July 30, 2019, 10:25:22 am
content: Thanks for reply..If it is for 1 quantity then probably i would not worried about failure.. here I'm going to make at least 250 pieces. that is why i though asked here so experience people can share their knowledge.I'll purchase couple of board and will check and compare performance.

author: ogden
author_rank: Super Contributor
timestamp: July 30, 2019, 10:35:39 am
content: Quote from: jtronix on July 30, 2019, 10:25:22 amFor such volume you may consider to use driver which is specified for 3.3V, such as MAX6958/MAX6959

author: jtronix
author_rank: Regular Contributor
timestamp: July 31, 2019, 04:22:31 am
content: Thanks everyone for support...Maxim chips is little expensive hence not consider for my application. Rather I would preferred to go with transistor.Just one last thing about Chinese chip Is it suitable for Industrial environment?Chinese manufacturer's parameters in datasheet usually not match with practical condition or they have just written for marketing puporse... I don't know about this chip

author: Dabbot
author_rank: Regular Contributor
timestamp: July 31, 2019, 08:01:36 am
content: Maybe you could consider TLC5917 instead.http://www.ti.com/product/TLC5917Here's the datasheet:http://www.ti.com/lit/ds/symlink/tlc5917.pdfCheaper and operates down to 3.3V