DAC63204EVM: DAC53204

Hello, 

The GUI is meant to be used with the DAC63204EVM. We have not tested it with the FT4222EV. Can you provide a higher resolution image of the FT422EV (or better, a picture of your FT4222EV) with the exact configuration it is in. I need to see if there are any jumpers or resistors populated/unpopulated. I would start with disconnecting the FT4222EV from your board. Connect the EV to the computer and measure the I2C pins with an oscilloscope. Do you see the I2C signals when you start a read or write in the GUI. Is the GUI operating in demo mode or does it say it's connected? 

We do not have python libraries available at this time, but there are many I2C examples available online if you google FT4222 python. Here is one that I found: https://pypi.org/project/ft4222/

Best,

Katlynne Jones

HI Katlynne Jones,

Thanks for your prompt responses.

Its shows that its connected.

Please find the below link the EV datasheet for your reference.

UMFT4222EV - USB2.0 to QuadSPI/I2C Bridge Development Module (ftdichip.com)

Operating in mode 3 

Also, i am facing the below error code,

Regards,

Dhanabal.K

HI Katlynne Jones,

Can we use the script in python?

Do i need any conversion? 

Snap from datasheet : 

Hi Dhanabal, 

I believe the GUI is expecting DCNF0 and DCNF1 to be connected to GND. Can you try connecting these to GND? Then power cycle the EV, close and repoen the GUI, and try reading again. 

The datasheet example is written in pseudo code. It is just telling you the registers and corresponding data you need to write. Once you have I2C working in python, you would just need to send I2C commands with 4 total bytes in the format of 1. I2C address, 2. Register address, 3. Register data (MSB), 4. Register data (LSB):

Best,

Katlynne 

Hi Katlynne,

I have tried by connecting the FT4222EV.

I am able to read the device ID  but unable do the margining.

.

I am not sure that whether the device id is correct or not.

When i am trying to do the margining, the tool enable option was not working.

Please support.

Hi Dhanabal, 

I checked the low level page and the GUI is combining the device ID and version ID into one field. So a device ID of 8 is correct for the DAC53204. Bit 3 is set to 1 which is 0x8:

I am not sure what you mean by this:

Dhanabal Kulandhaivel said:

the tool enable option was not working

What are you trying to do in the GUI, and what exactly isn't working? 

Best,

Katlynne Jones 

HI Katlynne Jones,

When i am trying to click the trigger button its not working.

Unable to select the trigger button.

Also i tried with DAC EV board facing this new issue.

Hi Dhanabal, 

These triggers are self resetting. The check box is not meant to remain checked. Once the trigger has been sent, the device automatically clears the trigger:

Are you not seeing the correct output from your circuit?

There was a bug with trigger buttons that I fixed in the SAMRT-DAC-EVM-GUI. The bug only affected the trigger when there was a long slew time, because the GUI would clear the trigger before the device was ready for it to be cleared. I don't think this is your issue considering that you are not using the slew, but you can try using the new GUI instead just to be safe.

https://www.ti.com/tool/download/SMART-DAC-EVM-GUI

Best.

Katlynne Jones

HI Katlynne Jones,

Today i tried with EVM .

I have removed the J3 jumper and applied the 1.8V external supply.

Noted that device id is not read by the GUI application.

Then i have increased the External supply voltage from 1.8v to 2.7V then found device id is getting detected.

Please help to solve the issue.

I understand that this device will work from the 1.8V as per the specification.

Please solve this issue. 

Hi Dhanabal, 

The I2C signals on the DAC63204EVM pass through a level translator before going to the FT4222 on board controller. I checked the datasheet for the level shifter and it looks like the minimum voltage for the VCCB pin is 2.3V. This is likely why the 1.8V supply is not working on the EVM. 

It looks like you can connect an external VCCIO voltage on the FT4222EV board:

You can try connecting this to 1.8V to get down to 1.8V IO voltages for the DAC. 

Best,

Katlynne Jones

HI Katlynne Jones,

Thanks for the clarification!...

We are trying to margin the LDO(TPS7A5701RTER) O/P using DAC53204RTER in current O/P mode.

When we try to do the margining 1.8V +10%. Its not working.

but We able to margin the  LDO O/P 1.8V - 10%.

The VDD of the DAC Is supplied with 1.8V.

We are using internal REF.

Kindly advise whether this circuit will work or not?

Hi Dhanabal, 

Thanks for confirming that you can margin to -10%. The issue here is your VDD voltage. The DAC current outputs have a required compliance voltage of 400mV from VDD. So if the voltage on the output pin is > 1.8V - 400mV then the DAC will not be able to regulate the current output. 

You will need to raise VDD to the max TPS7A57 output voltage you want to margin to plus the compliance voltage. The compliance voltage for the 25uA range is likely closer to 100mV based on this datasheet figure, so you can try (desired max TPS7A57 output + 100mV). 

Can you connect the DAC VDD to the 5V supply in the system? The digital IO voltages of the DAC can remain at 1.8V logic. 

Best,

Katlynne Jones

Hi Katlynne Jones,

Thanks for the responses.

Since our board is fabricated, we unable change the VDD voltage levels now. Its permanently connected to the 1.8V levels.

Also, as per the LDO datasheet we just need to margin the current of +/- 1.25uA.

Its not required to do +/-25uA. 

Regarding the Python script,

How do we send the comment using the Python.

 Can we get some examples? 

We are writing in the below format
slave = 0x70
MuxChnEnb[0] = 0X06
writedata = bytes(MuxChnEnb)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Dac53204 = array('B', [ 0x00,0x00,0x00,0x00])
slave = 0x49
#DAC0_DATA====>0x93195540
Dac53204[0] = 0X93
Dac53204[1] = 0X19
Dac53204[2] = 0X55
Dac53204[3] = 0X40
writedata = bytes(Dac53204)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Hi Dhanabal, 

There will still be some headroom required from the IOUT pin to VDD. The pin will not output any more current while the headroom is not being met. You will not be able to go above 1.8V on the IOUT pin with a 1.8V VDD. 

What is they byte 0x93 for in DAC53204[0]? The next three data bytes are correct to write data to the dac-0-data register. The first byte should be the I2C address 0x49, but it looks like this is already being included in this line:

Dhanabal Kulandhaivel said:

slave = 0x49

I think you only need to be writing these three bytes in that case:

Dhanabal Kulandhaivel said:

Dac53204[1] = 0X19
Dac53204[2] = 0X55
Dac53204[3] = 0X40

Have you been able to run this code and capture the output on an oscilloscope? That would be the best way for me to verify if the format is correct. 

Best,

Katlynne Jones

Hi Katlynne,

This is the Waveform captured in Oscilloscope from above Python Code.

And still we couldn't enable DAC.

Hi Sri, 

The image did not come through. Can you try posting it again?

Best,

Katlynne Jones

Hi Katlynne,

This is the Waveform captured in Oscilloscope from above Python Code.

Python code,

import sys, ftd2xx as ft

'''
Channel0=0x04
Channel1=0x05
Channel2=0x06
Channel3=0x07
'''

def I2cDrv():
import ft4222
import ft4222.I2CMaster
from array import array

# list devices
nbDev = ft4222.createDeviceInfoList()
for i in range(nbDev):
print(ft4222.getDeviceInfoDetail(i, False))

# open device with default description 'FT4222 A'
dev = ft4222.openByDescription('FT4222 A')

# init i2c master, clock speed 100kHz
dev.i2cMaster_Init(100000)

MuxChnEnb = array('B', [ 0x00])

slave = 0x70
MuxChnEnb[0] = 0X06
writedata = bytes(MuxChnEnb)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Dac53204 = array('B', [ 0x00,0x00,0x00,0x00])
slave = 0x49
#DAC0_DATA====>0x93195540
Dac53204[0] = 0X93
Dac53204[1] = 0X19
Dac53204[2] = 0X55
Dac53204[3] = 0X40
writedata = bytes(Dac53204)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Dac53204 = array('B', [ 0x00,0x00,0x00,0x00])
slave = 0x49
#DAC0_VOUT_CMP====>0x93030800
Dac53204[0] = 0X93
Dac53204[1] = 0X03
Dac53204[2] = 0X08
Dac53204[3] = 0X00
writedata = bytes(Dac53204)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Dac53204 = array('B', [ 0x00,0x00,0x00,0x00])
slave = 0x49
#DAC0_FUN_CONFIG====>0x93060017
Dac53204[0] = 0X93
Dac53204[1] = 0X06
Dac53204[2] = 0X00
Dac53204[3] = 0X17
writedata = bytes(Dac53204)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Dac53204 = array('B', [ 0x00,0x00,0x00,0x00])
slave = 0x49
#DAC0_MARG_HIGH====>0x9301A540
Dac53204[0] = 0X93
Dac53204[1] = 0X01
Dac53204[2] = 0XA5
Dac53204[3] = 0X40
writedata = bytes(Dac53204)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Dac53204 = array('B', [ 0x00,0x00,0x00,0x00])
slave = 0x49
#DAC0_MARG_LOW====>0x93020500
Dac53204[0] = 0X93
Dac53204[1] = 0X02
Dac53204[2] = 0X05
Dac53204[3] = 0X00
writedata = bytes(Dac53204)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

Dac53204 = array('B', [ 0x00,0x00,0x00,0x00])
slave = 0x49
#DAC0_CMN_TRI====>0x93200002
Dac53204[0] = 0X93
Dac53204[1] = 0X20
Dac53204[2] = 0X00
Dac53204[3] = 0X02
writedata = bytes(Dac53204)
print('data',writedata)
dev.i2cMaster_Write(slave,writedata)

I2cDrv()

thanks & Regards,

R SRI RAJA SUMAN

Hello, 

Please zoom in so I can actually see what a single write command looks like. I should be able to see every SCL pulse. 

I can't tell just from the python code you are sharing how the I2C is actually being written out to the device. 

Best,

Katlynne Jones