View Full Version : New FTDI chips

03-24-2012, 09:36 AM
There seem to be some new FTDI chips, such as the FT230X (http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT230X.pdf)

There are a little cheaper than the FT232R, and available in 16 pins, about half the size of the FT232RL. This is good news because the FT232RL is largish, and FT232RQ difficult to hand solder. Cheaper too.

There are are some USB<>I2C converters in the new range too

Anyone had a look yet?

03-24-2012, 11:03 AM
There seem to be some new FTDI chips, such as the FT230X (http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT230X.pdf)

Nice looking parts, 50mA available at 3v3, and with MTP memory and no crystal. (claims 1667ppm)
Also gives 24MHz 12MHz and 6MHz clock out choices

ON the clocks it says this
["*When in USB suspend mode the outputs clocks are also suspended."]
and also this

["Keep_Awake# CBUS0, CBUS1, CBUS2, CBUS3
Prevents the device from entering suspend state when unplugged."]

So maybe you can configure it to always deliver a clock ?

Good baud rate choices too..
Baud Rate = 3000000 / (n + m/8) { n >= 1, m = 0..7, if n=1 then m=0}

I see they also have a 10 pin i2c slave part, and SPI variants...

A pity the extended Config memory cannot allow _one_ part number to do SPI and UART ?

03-24-2012, 11:54 AM
They are available from Farnell, D-K, Mouser, etc.

I was going to use the FT232R in a design, but I think I'll use the new chip.

03-24-2012, 12:30 PM
prices are considerably lower and the chips are smaller. However, the pin spacing is tight at 0.635mm.

I wonder if it could be possible for someone to write a com driver that pulsed the gp pin for reset to save using the transistor reset circuit.

03-24-2012, 12:38 PM
Is it 1/2 the price of FT232RL? That is a real motivator...
I'm trying to figure out what this battery charge monitor signal is all about...
Need to see if the default mode for the GPIO is the same... It's a real pain to reprogram every chip...

03-24-2012, 12:44 PM
Hi Cluso,

i'm using a small board with the CP2102-chip for downloading code into the prop. But - in this post - I don't want to focus on the chip. I connected the DTR-pin of the board over a 0,1 F-capacitor to the reset-pin of the propeller-chip.

So far I haven't experienced any problems with this "no-transistor"-circuitry. Is this just luck or do you want to aproach something different with the transistor?
best regards

03-24-2012, 01:09 PM
Might be hard to choose between 230 and 231... 230 is smaller and cheaper, right?
But, 230 doesn't have DTR... So, you'd have to tell Prop Tool to use RTS instead...

03-24-2012, 02:40 PM
I'm working on a Propeller PCB design using it. Schematic (partly completed) is attached.

03-24-2012, 03:06 PM
Leon, I think your circuit has a lot of problems... So, I'd like to hear how it works for you...

03-24-2012, 03:17 PM
What are they? It's very much a work in progress.

The FT230XS 3.3V supply is only 50 mA, so I might add a regulator.

03-24-2012, 03:37 PM
I think the 230, 231 chips are really just repacked versions of the FT232RL chip. Might be wrong, but at first glance it looks like the pins work the same way...
So, I think the designs of the Quickstart or other boards are still good places to start from.

Leon, I don't think the LEDs will work the way you have it... Also, I think I'd pick RTS instead of CTS... My version of Prop Tool (old?) works with RTS and not CTS.

03-24-2012, 04:24 PM
It's a completely new chip. I used the circuit in the data sheet.

I should have used RTS. Schematic has been updated.

03-24-2012, 06:19 PM
Chips are new. But, I seriously doubt it's a "Completely New" design.

Here are the differences I see:
1. smaller and cheaper
2. battery charging mode
3. you now need external resistors and capacitors on the USB signal lines

Anything else?

Phil Pilgrim (PhiPi)
03-24-2012, 06:49 PM
I just made a rather astounding discovery. I was looking at the FTDI datasheet and saw a reference to the Micrel MIC2025-2BM soft-start IC. So I copied and pasted that part number into (what I thought was) the Google search box. But, instead of the typical Google page, up popped the datasheet in the PDF reader! I'd never seen that happen before, and went back to Firefox to investigate. It turns out that, instead of typing the part number into the search box, I had typed it into the address (URL) field. I'm using OpenDNS (www.opendns.com) as my DNS provider, so maybe that's a service that it provides that I wasn't aware of. Or maybe Firefox intercepts the bogus URL and redirects it?

I've tried it with other part numbers. Sometimes it opens a PDF datasheet; other times it redirects to a manufacturer's product page for the part.

Anyway, 'sorry for the hijack.


03-24-2012, 07:50 PM
Its a new design. See the errata sheet. Guess they had to compete with the CP2102 which is apparently much cheaper (not on DigiKey though).
Note it also requires series resistors to the USB and a few more caps :(

Stefan: I have successfully used a CP2102 board by tying the DTR directly to the prop reset. The problem occurs when switching between windoze/linux programs when the DTR gets toggled.

03-24-2012, 07:50 PM
When Firefox is given an invalid URL, it doesn't attempt to determine the actual URL.
Instead, it performs a "I'm feeling lucky" google search when confused and returns the first matching web page.

Also some DNSservers make money on invalid ursl and show ads instead.

03-24-2012, 10:13 PM
3. you now need external resistors and capacitors on the USB signal lines

That looks like rather like an 'oops', hard to imagine the designers starting saying :
'Hey, we are making a low cost, smallest footprint chip, let's add 2xR ans 2xC, lest this gets TOO small '

- I can see series R could help ESD figures, but surely the average cable already has that C?
Did they fail a EMC test, and needed a RC band-aid ?

03-25-2012, 02:44 AM
It is a little strange... Just as a guess, I've heard that real resistors and capacitors take up a lot of silicon space.
So, maybe they moved them off the die to make it fit the smaller package?

Or, you could be right and they just messed up and needed this fix...

WBA Consulting
03-25-2012, 06:38 AM
In regards to the external parts, I know of other chips that did the same "improvements" because many designs using their parts already had the values in question on the board elsewhere. So, in volume, it is much easier to add 2 more resistors at $0.0015 each and a few more caps at $0.004 each than to switch to a different IC that costs $2 more to save a few parts on the board. FTDI services customers at much higher volumes than us hobbyists, so that is where this solution to compete with the CP2102 probably comes from.

Phil Pilgrim (PhiPi)
03-25-2012, 07:06 AM
If you're using a service bureau to populate your boards, you also have to figure the total number of components for the pick-and-place charge and the number of different components for the P&P setup charge. That can easily erase the savings in parts cost alone, and then some.


03-25-2012, 10:38 AM
And that also adds to real estate, taking away from any savings in space. BTW the resistors are supposed to be about 68R for the USB spec, so seems they goofed and the resistors are only about half that value!

03-25-2012, 10:54 AM
Perhaps it has internal resistors and they got the value wrong.

03-25-2012, 04:03 PM
But, 230 doesn't have DTR... So, you'd have to tell Prop Tool to use RTS instead...

What version of Propeller Tool has this? Where does one find the option?

Phil Pilgrim (PhiPi)
03-25-2012, 04:07 PM
I know version 1.3 has it. You can find it in the options (or somesuch name) menu and can choose DTR, RTS, or both.


03-25-2012, 04:57 PM
Edit > Preferences > Operation. It took me some time to find it.

03-25-2012, 07:01 PM
Thanks Phil and Leon.

03-25-2012, 07:24 PM
To me those external components look like they are required for formal compliance with the USB spec, or for EMC reasons, or for marginal installations without cables.

I suspect it is a case of "they technically should have been included on the FT232R circuit" rather than a goof on the new chip.

The 47pF caps.... USB cable capacitance is about 20pF/foot, so the value of these 47pFs is dwarfed even by a 6 foot cable.

03-25-2012, 11:20 PM
Another possiblility is that they wanted to use smaller protection diodes. Most devices I've seen like this need external protection diodes. FTDI has them internal, but they probably also take up a lot of space. Maybe adding this RC filter to the front end allows them to use smaller protection diodes...

User Name
04-18-2012, 07:13 PM
For those who find PCB layout more about tedium and less about recreation (raises hand), it really is pretty difficult to beat a CP2102 board on eBay. They cost less than $3, shipping included. My experience has been that the Silicon Labs drivers (downloaded from their website) work flawlessly in Windows 7.

04-18-2012, 07:34 PM
FT231X is cheaper than CP2102 at Digikey.

Here's how the FT231X looks compared to FT232RL BTW:

Phil Pilgrim (PhiPi)
04-18-2012, 07:49 PM
It must still be a largish die if they have to extend the package that far beyond the pin footprint.


04-18-2012, 08:06 PM
I'm not sure why the FT231XS is so big compared to the FT230XS.

The QFN versions of both are 4mm x 4mm, so its not the die size

Martin Hodge
04-18-2012, 08:23 PM
There's not much space savings considering the extra 4 components needed for the 231X.

04-18-2012, 08:48 PM
Looks like it might be a 24 pin package with a 20 pin lead frame. Maybe it was designed as a 24pin and they opted for a 20pin lead frame at the last minute, then updated the datasheet to match.

07-16-2012, 11:51 PM
Just got a notice from FTDI that there is a design flaw with the current X-chip family.... Ouch...
Seems sending a certian bit pattern will make it go into suspend mode...
Workaround is to force it to stay awake by disabling suspend...

07-17-2012, 12:02 AM
You know I was just thinking yesterday of changing a couple of designs over to the new chip.

Oddly, I feel more comfortable now that they have found a reasonable sized bug (so long as suspend mode is not required). I'm surprised though that something that big wasn't found earlier... guess it depends on the size of the vector pattern

Thanks for sharing...

07-17-2012, 04:19 AM
Looks like it might be a 24 pin package with a 20 pin lead frame. Maybe it was designed as a 24pin and they opted for a 20pin lead frame at the last minute, then updated the datasheet to match.

I think that is just a quirk in the SSOP20 package generally, as you say, they have one molding machine for two pin counts.

WBA Consulting
08-02-2012, 07:31 PM
FYI: The first two versions of this FT230X chip have issues and are being recalled. A partial snippet from the notice:

As part of our business’ quality management system, we have identified an issue with the
X-Chip Product family that in certain user applications can cause the transfer of data over
USB to stop unexpectedly.
Our investigations into this matter have identified that the device may go into suspend
mode during a transfer of certain data patterns most notably with binary zeros. This can
halt the data transfer in certain circumstances and will require the device to be reenumerated
to recover.
Analysis has revealed that the issue is application specific, and where devices have been
utilised within a new design specification and functioned correctly, there is likely to be no
subsequent issue; however we would not recommend the use of current revision B and C
devices for mass production volumes.

08-02-2012, 09:25 PM
Thanks WBA

I had assumed the bit pattern might be something more complicated than all zeros! That sounds nasty.

I hope they'll patch it up for rev D and we can be up and running again.

08-02-2012, 09:32 PM
I thought it might be worth posting the recommended solution here:-

"This issue can be avoided by utilising the keep awake function of the chip. This will disable the USB
suspend function of the chip and is therefore an intermediate workaround until revision D silicon is
released with a permanent fix.

NB. With the workaround the chip will never enter lower powered suspend. However the keep awake
current will be approximately 3mA.

To enable the keep awake function in the EEPROM, one of the CBUS pins needs to be configured as KeepAwake#. This pin then needs to be tied to ground on the PCB. The FT_Prog utility can be used to
configure the CBUS pin."

WBA Consulting
08-03-2012, 07:27 AM
Tubular, I completely agree. Fortunately, my board with this FT230X (designed mostly by a colleague) appears to be working fine without using KeepAwake#. The FTDI chip is powered from the 5 volt output of the buck/boost switcher circuit (not Vusb 5V). Then, CBUS3 is pulled to 3.3v through a voltage divider circuit off of 5V and CBUS3 on the FTDI is reprogrammed to VBUS_Sense. In effect, this prevents the FTDI from being powered down as well, but with the resistor voltage divider circuit, you can pull the CBUS3 pin high or low (by changing resistors loaded) and set CBUS3 to one of the other options to change the operation of the FTDI depending need.

After debugging a reset issue on our prototypes tonight, the board is working fine. From that, I can say that the FT230X chip has been proven as usable with the Propeller. (of course you must change the reset drive in PropTool to "RTS & DTR" so it works with both FT230X circuits and the normal FTDI USB circuit used on all other USB Propeller boards) I hope to share details of our design in a few weeks.

01-11-2013, 06:50 PM
My PropWifi design uses the FT230X

Though I can see that I can reverse RTS# in its MTP memory, there is no settings for Push/Pull vs open drain.

As I have no push-reset button, but I guess the Prop can pull the RESn line to ground in software and causing a short.
Is the cap in series, plus pulldown and transistor still the best (least parts) option?

01-11-2013, 08:24 PM
If you can invert the RTS then a Cap (~1nF) between RTS and RES input is all you need. BOEn must be connected to Ground to enable the internal PullUp at the Reset input.

The Propeller pulls the RES line only to Ground if a BrownOut occurs, and with BOEn Low this is disabled.


Erik Friesen
04-11-2014, 05:19 PM
Note: After adding the FTDI FT230X to a design, I am rather frustrated, as it is rather buggy. Nothing like the proven ft232 so far. I have rev D, which is supposed to be fixed from something. My suggestion is to avoid this chip like the plague.


Randomly quits working after 5-30 minutes, just quits passing data, dying on the chip level perhaps, the TX/RX lights quit blinking.

As of this writing, I have a chip that windows won't recognize, from nothing more than unplugging and replugging after a problem. I have never seen anything like this in the ft232 series.

04-13-2014, 11:57 PM
I think Parallax now use the FT230X on a number of boards, so you could check one of theirs, or one of the UMFT230X modules, to see if the same issues appear ?

The new FT51 looks interesting too, slightly more in price, but much smarter. with i2c and ADC and DAC, so a Prop board could add that for Fast Serial as well as a i2c ADC/DAC expander.