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Chip of the day!!!.........
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SiliconWizard:

--- Quote from: Smokey on July 10, 2023, 07:48:32 am ---
--- Quote from: floobydust on July 10, 2023, 01:12:11 am ---
--- Quote from: Smokey on July 09, 2023, 09:05:09 am ---LM7705 Low-Noise Negative Bias Generator
https://www.ti.com/lit/ds/symlink/lm7705.pdf

3V-5.25V Input
-0.23V Out at about 20mA
Good for those "RRIO" opamps if you actually need actual RRIO

Only $0.86 in 1s at Digikey
https://www.digikey.com/en/products/detail/texas-instruments/LM7705MMX-NOPB/2020262

--- End quote ---

Um all that work for -0.23V? I am confused...  The ICL7660 came out in 1980 and gave more, like -5V.

--- End quote ---

There is a good answer to this one.  Say you are using a single supply opamp like the TL900x series:
https://www.ti.com/lit/ds/symlink/tlv9002.pdf

It has a supply range up to 5.5V.  If you are already running it from a +5V rail and all you need to actually output 0V, then you only have at most -0.5V that the negative rail can be.  Since you only need about -20mV for the supposedly RRIO to be able to drive to 0V, the -0.23V of the LM7705 is more than enough to keep the opamp in the recommended operation range and drive 0V out.

--- End quote ---

Yes, but it's not just about being enough for the job - it can achieve a significantly lower output ripple than the venerable ICL7660. Hence why it's marketed as "low noise".

nctnico:
Currently I'm quite pleasantly surprised by the abilities of the ESP32-S3 chip. Only downside I've seen so far is the crappy ADC but other than that the software ecosystem is nice, well documented and the chip is very capable.
VK3DRB:

--- Quote from: nctnico on July 10, 2023, 10:22:53 pm ---Currently I'm quite pleasantly surprised by the abilities of the ESP32-S3 chip. Only downside I've seen so far is the crappy ADC but other than that the software ecosystem is nice, well documented and the chip is very capable.

--- End quote ---

You are right, the ESP32's in general are great other than the ADC. Super low cost and unlike other MCU suppliers (Microchip, TI and STM), I could get ESP32-C3's during COVID - and that is the reason I used them in two projects, albeit at risk. Also used an ESP32-S3-WROOM. You can calibrate the ADC's but still they are mediocre at best. No good for accurate analogue measurements, but I did use it on one project for a non-critical battery fuel gauge (could not get fuel gauge chips during COVID) and it was OK.

Espressif's BLE documentation is a dog's breakfast. Their hardware datasheets has ambiguity in them and is missing some detail that would be found in, say, TI and Analog Devices datasheets. The ecosystem is satisfactory but not great. Mind you I recently found a glaring pin-out error in Texas Instruments two year-old chip that no-one at TI had even picked up. The pinout list showed input pin for CAN bus data incorrectly described as a chip enable pin :wtf: TI's documentation QA is in trouble if such an error can exist for two years before they know about it. Overall Espressif does a reasonable job with their English documentation, considering it is a Chinese company.

No complaints though, because ESP32's got me out of a bind during COVID. Super low cost, which is good for high volume cost-sensitive projects. Plus I learnt to use a new MCU.
Warhawk:

--- Quote from: VK3DRB on July 13, 2023, 07:28:59 am ---
--- Quote from: nctnico on July 10, 2023, 10:22:53 pm ---Currently I'm quite pleasantly surprised by the abilities of the ESP32-S3 chip. Only downside I've seen so far is the crappy ADC but other than that the software ecosystem is nice, well documented and the chip is very capable.

--- End quote ---

You are right, the ESP32's in general are great other than the ADC. Super low cost and unlike other MCU suppliers (Microchip, TI and STM), I could get ESP32-C3's during COVID - and that is the reason I used them in two projects, albeit at risk. Also used an ESP32-S3-WROOM. You can calibrate the ADC's but still they are mediocre at best. No good for accurate analogue measurements, but I did use it on one project for a non-critical battery fuel gauge (could not get fuel gauge chips during COVID) and it was OK.

Espressif's BLE documentation is a dog's breakfast. Their hardware datasheets has ambiguity in them and is missing some detail that would be found in, say, TI and Analog Devices datasheets. The ecosystem is satisfactory but not great. Mind you I recently found a glaring pin-out error in Texas Instruments two year-old chip that no-one at TI had even picked up. The pinout list showed input pin for CAN bus data incorrectly described as a chip enable pin :wtf: TI's documentation QA is in trouble if such an error can exist for two years before they know about it. Overall Espressif does a reasonable job with their English documentation, considering it is a Chinese company.

No complaints though, because ESP32's got me out of a bind during COVID. Super low cost, which is good for high volume cost-sensitive projects. Plus I learnt to use a new MCU.

--- End quote ---

Which TI chip? I get it fixed.
Simon:

--- Quote from: Smokey on July 09, 2023, 09:04:16 am ---Find an interesting/useful part? 

Think other people will also think it's interesting and/or useful? 

Post it here. 

Chip of the day!

--- End quote ---

No thanks, I want them to be available tomorrow  ;D
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