I2C level shifter

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rommelm

Joined: 02 Sep 2004
Posts: 36
Helped: 1

09 Dec 2004 6:44 i2c level shifter

I have this project that I need to Level shift a I2C bus from 1.65V to 6.5V.

I'm planning to use MOSFET as level shifter... do you have other better IDea...

also if you have a driver, or controller that you can recommend...
with my speed requirement, I am but limited to FPGA only. PIC can operate to a mere 1MHz only..

My specs:

1. around Max 20MHz operation[To be used for testing I2C device]

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Bingo600

Joined: 26 Aug 2004
Posts: 239
Helped: 14

09 Dec 2004 22:14 mosfet level shifter

Have a look here (page 7 and on)
Have a look here
http://www.standardproducts.philips.com/support/appnotes/i2c/pdf/an97055.pdf

http://www.brive.unilim.fr/geii/electronique/docs/catalogue_i2c_philips.pdf

This guy does some other cute things using above AppNote
http://delphys.net/d.holmes/hardware/hardware.html

This is a Phillips chip bot only doing levelshifting betveen 1v..5v
http://www.standardproducts.philips.com/support/appnotes/specialty/pdf/an10145.pdf

Hope this helps out

Ohh...
Btw: About Pic running 1Mhz.
Atmels Mega8 or 16 or 32 runs at true 16Mhz , and have TWI (I2C) hardware interface

/Bingo

rommelm

Joined: 02 Sep 2004
Posts: 36
Helped: 1

14 Dec 2004 2:59 level shifter i2c

Thanks BINGO,

Thats the approach I'm planning to take...

right now I am we are considerind the BSN20 of philips...

I was wondering if other guys have a better IDea on how to solve my problem.

so far, using mosfet is the best.....

Bingo600

Joined: 26 Aug 2004
Posts: 239
Helped: 14

17 Dec 2004 20:00 i2c level

@rommelm

Did you have a look at the Atmel chips ??

The new Mega48/88 runs at 20Mhz genuine Risc giving 20 MIPS , most of the Megas have I2C hardware support , called TWI (Two Wire Interface) because Phillips owns the I2C name.

/Bingo

eziggurat

Joined: 15 Feb 2002
Posts: 226
Helped: 9

20 Dec 2004 22:15 i2c level shifting

Pericom and On semiconductor does some good level shifters.

rommelm

Joined: 02 Sep 2004
Posts: 36
Helped: 1

21 Dec 2004 2:48 level shifter for i2c

Hello again Bingo,

I already checked the Atmel chips but the bus speed of the TWI is upto 400KHz only.

Can we drive it upto 20Mhz?

mitesh

Joined: 13 May 2002
Posts: 288
Helped: 6

25 Dec 2004 8:08 i2c level shifter mosfet

I want a cheap level shifter from 3 volts to 5 volts. Can any body suggest me.

Ace-X

Joined: 25 Jan 2002
Posts: 590
Helped: 26

26 Dec 2004 14:02 i2c level shift

mitesh wrote:

I want a cheap level shifter from 3 volts to 5 volts. Can any body suggest me.

I ordered MAX3002 (check also MAX3001 and MAX3003) for my new project. They are quite cheap (2.3$) and have 8 independent bi-directional channels. They are pretty nice - you don't have to bother about directional control, just put them between.
Also, Analog Devices have new IC converter with similar features.