3.3v for SB6121

SB6XXX,SBV6XXX

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usbbdm
Junior Member
Posts: 8680
Joined: Mon Jul 18, 2005 9:33 pm

3.3v for SB6121

Post by usbbdm »

I have a user constantly talk to me over the chat that he cannot program SB6121.
In my youtube video https://www.youtube.com/watch?v=pFoXLnORZyY&t=9s I used a hack from USB JTAG NT to get 3.3v. Actually the 3.3v from USB JTAG NT is a little higher and not very reliable.
In his setup he used 3.3v from TTL and never worked for him.
Today I measured the power and found it drain about 450mA from the TTL and failed. The power supply also drops to 2.8XV.
So in this kind of setup, you should get a good source of 3.3v that can provide 750mA or bigger to get reliable programming.
The USB powered device can provide 500mA max include USB JTAG NT itself.
Make yourself a good 3.3v source is the key to get this kind of setup working.
If you program the chip off the board , then TTL 3.3v should be sufficient. When programming on the board, you are not only powering the SPI flash, you are also powering other devices on the board.
georgie21
Junior Member
Posts: 4
Joined: Sun May 24, 2020 3:51 pm

Re: 3.3v for SB6121

Post by georgie21 »

I used an external adjustable power supply and at 2.25 volts I was able to detect chip. 3.3 volts didn't work. People who get errors detecting should consider getting an adjustable power supply and drip voltage. Just 2 cents
usbbdm
Junior Member
Posts: 8680
Joined: Mon Jul 18, 2005 9:33 pm

Re: 3.3v for SB6121

Post by usbbdm »

Thank you. I think lower voltage is both safe to use and have higher success rate.
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