IDT DAC1627D Quick Start Manuals

1

DAC1627D Demo bo ards – Quick Start
v2

2

CGAP2 board:

Storage and Generat ion of

complex patterns up to

32M (I,Q)- words

DAC1627D board

DAC1627D demoboard+ CGAP2

Board presentation

3

DAC1627D SPI

USB control

CGAP2 USB

Power 5 Vdc

SMA100A clock generator : DAC clock

Power 5 Vdc

PXA spectrum

analyzer

DAC1627D demoboard+ CGAP2

Board connections

PXA spectrum

analyzer

DAC1627 Board overview

Block Diagram

FT2232D

USB<-> SPI

DAC1627

Iout

SPI

DAC clk

USB

con

Data0-13

DAC

6V DC in external

Power Generator

Qout

DAC

CGAP2 QSH connector

SPI

LVDS clk

Divider

/2 /4 /8

splitter

global clk

Iout
Qout

One Global clock is used for both DAC board and CGAP 2 boar d.
This Global Clock is split on two signals:

- one is feeding the DAC1627D

- one is divided and send trough the Samtec connector to the CGAP board to feed the FPGA

5

CGAP2 board:

Storage and Generat ion of

complex patterns up to

32M (I,Q)- words

DAC1627D + BGX7100 board

DAC1627D + BGX7100 IQMod demoboard+ CGAP2

Board presentation

6

DAC1627D SPI

USB control

CGAP2 USB

Power 5 Vdc

SMB100A clock generator, DAC clock

737.28MHz, 5dBm

Power 6 Vdc

SMA100A clockgen
IQMod clock 2GHz,

0dBm

PXA spectrum

analyzer

DAC1627D + BGX7100 IQMod demoboard+ CGAP2

Board connections

DAC1627/ BGX7100 Board overview
Block Diagram

Low pass Filter

(BW=300Mhz)

FT2232D

USB<-> SPI

DAC1627

Iout

RFout

SPI

DAC clk

USB

con

Data0-13

DAC

6V DC in external

Power Generator

Qout

DAC

External generator

LO Synthe

clock

CGAP2 QSH connector

SPI

LVDS clk

Divider

/2 /4 /8

splitter

BGX7100

AQM

global clock

One Global clock is used for both DAC board and CGAP board.

This Global Clock is split on two signals:

- one is feeding the DAC1627D

- one is divided and send trough the Samtec connector to the CGAP board to feed the FPGA

S0/S1/S2 jumpers positi on

8

S0: ON
S1: ON

S2: OFF

S0/S1/S2 jumpers are used to configure the divider ratio for the clock feeding the CGAP board..
For the current software revision, t he ratio value needs to be set to 2.

Please, make sure that the jumpers have the foll owing configuration on the boar d:

CLOCKS generation
(Global Clock and LO)

9

Spectrum measurement

Bench overview

10

IDT DAC1627 SPI Software

Software Folders

11

Documentations: Datasheets and QuickS tart

LabVIEW Runtime version 8.6

FTDI USB drivers for CGAP and DAC1627 controls

Main Application

3

1

2

To use the IDT_DAC1627D software, the LabVIEW Runtime 8.6 needs to be installed first.
This Runtime could be f ound on the folder named 1_LabVIEW Runtime 8.6.
The driver required t o ac c es s the USB controller on the boar d c ould be found in the folder 2_USB driver

CGAP board control panel overview

12

Warning: Exiting the Program

13

When using the IDT DAC1627D SPI Software, some USB connexion are opened
between your laptop/desktop and the boards (CGAP 2 and DA C board).

To prevent any hardwar e is s ue when closing the program

, please use the EXIT

button to close properly the USB connexion.

Do not use the [X] button, otherwise, the U SB c onnexion will still

be alive, and the program won’t be closed properly.

If this happens, the program will be displayed i n t he Windows taskbar, but could not be
accessed anymore.

Please use the Task Manager to End the process:

CGAP board start up sequence

14

(1) Initialize the CGAP board USB controller

(2) Specify the Global Clock frequency pr ovided to the DAC board.

(3) Specify the interpolation factor programmed in the DAC1627D.

(4) Specify the clock phase realtionship between the LVDS clock and the
DATA coming from the FPGA.

(5) Press the ‘DATA CLOCK’ button to configure t he CG A P board.

Create Pattern s and program CG AP memories
1/3

15

Select the ‘Create Pattern s’ tab

16

Create Pattern s and program CG AP memories
2/3

(a) Select the number N of samples
(b) The Data Frequency is automatically preset fr om the Global clock

value and the interpolation fac t or
(c) Specify the Frequency of the first tone (Hz)
(d) Specify the Amplitude of the f ir s t tone (dBFS)
(e) Click ‘Two T ones’ if needed
(f) Specify the Frequency of the second tone (Hz)
(g) Specify the Amplitude of the sec ond tone (dBFS)

Press ‘Create Patterns’ button to generate the s ignal (I and Q patterns are
generated at the same time)

Press ‘Load in Memory’ button to load the pattern f iles to the CGAP board
memories.

17

Create Pattern s and program CG AP memories
3/3

The complex spect rum of the generated si gnal is displayed.

The size of the pat tern indicator is ref r es hed.

The LED indicators diplays the status of the CGAP board (Programmed
and Generation)

The generation of the signal is automatically enabled after t he « Load in

Memory » action.

LED Status of the CGAP board

18

When Generation is in pr ogr es s , the

GEN LED is ON (green)

When the clock configuration is correctly

set, the ALIVE LED is blinking (green).

When the ERROR LED is blinking (red),

the clock configuration need to be resent.

Load Patterns Files

19

Some patterns are already available with the sof t w ar e.
You need to specify the DATA rate (w) and the type (x) of signals ( Radi o or S ines waves).
Then, I-file and Q-file need to be selected (y).
Press Load in Memory (z) to store the pattern in the FPG A memory

X

Y

W

Z

Y

20

Load Patterns and program CGAP memories

In the « patterns » folder, several subfolders are prov ided containing various
pattern types regarding the expected frequency of the DATA signal.

Each subfolder is splitted in two subfolders names Radio and Sinewaves.

The Radio subfolder contains the Radio complex patterns ( WCDMA, GSM, etc).

The Sinewaves subfolder contains the basic s ingl e or dual tones signals.

Any patterns could be added t o this subset, please contact your local AE to know
more about this process.

This structure is r epr es ented in the same way in the GUI.

DAC control s panel overview

21

DAC control s main features

22

Some SPI settings ar e alr eady available in the
DAC Config boxes.
Select the right one, and Press Load Config
button.
You can reset the device by pressing Reset to

Default button.

You first need to press Re-INIT USB device to
be sure that the PC is able to communicate
with the DAC1617D

All the registers could be read to update the
Graphical User Interface by pressing READ

from the DAC button.

All the registers could be written by pressing

SEND to the DAC button.

On all DAC tab:

When entering each TAB, a self refresh feature is enabled to display the real content of the DAC device.

DAC Main Configuration

23

Main parameters of the DAC settings (NCO, interpolation) could be programmed from the Main tab.

NCO enable / disable

24

When using the NCO, don’t forget to specify the type of modulation.

Positive or negative refers to the pos ition of the final signal compare to the LO

position after the Iqmod.

Upper and Lower refers to the position of the signal c ompare to the NCO position.

When disabling the NCO, don’t forget to specify no modulation.

Interpolat ion f a ctor

25

The interpolation f ac tor need to be specified in two pages .

In the Main tab, please specify the interpolation ratio 

In the Data Format / INTR tab, please specify the CDI mode 

Please respect t he follwing table :

Interpolation CDI mode

x2 ^2 mode
x4 ^4 mode
x8 ^8 mode

DAC digital Adjustement

26

DAC digital tuning tab allows to update digital gain, phas e c or r ec tion, clipping of the I/Q c hannels to help the I/Q balance at
the AQM input.

Image Rejection compensati on (experimental)

27

The Image Rejection compensation
window allows to instant aneous ly
update the I/Q gain and the phase
compensation.

Mouse or keyboard inter face could be
use to update the values.

Notice: This feature is experimental for
the moment, and could s how s ome
bugs.

DAC analog ad justement

28

DAC analog tuning tab allows to update the analog gain, the auxiliar y DA Cs .

Multi Devices S ynchronization

29

MDS tab allows to tune the settings for the multi devices synchronization.

LVDS Clock Control

30

LVDS buffer are automatically c al ibr ated with regard to the LVDS clock input.
The tab allows to enable/disable the automatic/manual calibration.

Data Input Formatting

31

Interleace/Folded, bit inversions of t he input interface could be set up in t he Data input formatting tab.

Test

32

Registers

33

All the registers pages could be read and save from t he Regis ters tab.

Tools

34

Tools tab allows to see the output spectrum related to the folded image at the DAC output.

35

Spectral measurements

How to correctly setup your spectrum analyzer?

How to specify the correct settings for the Spectrum analyzer?

36

DAC1627D and BGX7100 provides high end performances, therefore, a correct m easurem ent

setup need to be established to get the real perf orm ances of the dev ic es (and not the bad
performanc es of the spectrum) .

Please refer s to t he Application Not e f r om Agilent to correctly setup the Spectrum.
Same way of working c oul d be used for R&S equipment.

37

How to specify the correct settings for the Spectrum analyzer?

Mixer will created second and third
order distorsion if too much power

is send at its input.

Attenuation needs to be correct ly

set up to avoid t he mixer’s

distorsion to occur.

38

How to specify the correct settings for the Spectrum analyzer?

You need to find the opti mum mixer levels to
avoid to measure the dis torsion created by the
equipment.

Third order distorsion created by the

Spectrum Analyzer

Second order distorsion created by the

Spectrum Analyzer

Displayed Average Noise Level due to the

Resolution BW

Warning: Please refer to the S pec trum
Analyzer Datasheet to get the real value for
TOI and SHI

39

How to specify the correct settings for the Spectrum analyzer?

When measuring Second

harmonic (H 2) , you need t o take

care about the second order

distorsion of the analyzer.

Maximum value that could be measured from

the equipment in this s pec ific settings (RBW).

DANL
(link to RBW)

Second order
distorsion from
the equipment

Warning: Please refer to the S pec trum

Analyzer Datasheet to get the real value for
TOI and SHI

Optimum power level in f r ont of t he mixer.

The attenuation need to be adjusted to fit this
parameter.

40

How to specify the correct settings for the Spectrum analyzer?

When measuring Inter-

Modulation product (IMD3) , you

need to take car e about the third

order distorsion of the analyzer.

Maximum value that could be measured from

the equipment in this s pec ific settings (RBW).

DANL
(link to RBW)

Third order
distorsion from
the equipment

Warning: Please refer to the S pec trum

Analyzer Datasheet to get the real value for
TOI and SHI

Optimum power level in f r ont of t he mixer.

The attenuation need to be adjusted to fit this
parameter.

41

How to specify the correct settings for the Spectrum analyzer?

You need to find the opti mum mixer levels to avoid
to measure the distors ion created by the equipment.

When measuring a signal of 0dB m power, to avoid to
get H2 coming fr om the S pec trum analyser mixer, a ­40dB attenuator level need to be set (it also depends
of the RBW)

If the signal is about -10dBm, then use 30dB of
attenuation to get -10 -30 = -40dBm at the mixer
input.

When measuring Intermodulation pr oduc t (IMD3)
for a -6dBm signal, please us e 22dB at tenuation to
avoid intermodulation product coming fr om the
equipment.

-6-22= -28dBm at the mixer input.
Please update the figur es r egar ding the type of

equipment you are using (cf datasheet of the
equipment).

42

Spectral measurements

Understand OIP3 / IMD3 after IQModulator

Third Or der Intercept measu r ements

43

Please refers to the Application Note from Agilent for more details.

Definition of OIP3

44

In telecommunications, a third-order intercept point (IP3 or TOI) is a measure for nonlinear systems and dev ic es. T he
third-order interc ept point relates nonlinear produc ts caused by the third-order nonlinear term to the linearly amplified
signal, in contrast to the second-order intercept point that uses sec ond or der terms.

BGX7100 OIP3

45

OIP3 value is about 26dBm for

2GHz LO frequency

Intermodulation see at DAC outputs

46

No intermodulation after

DAC.

Intermodulation afte r IQMod (2Ghz)

47

Output Power= -6.33dBm
dBc= -63.12

OIP3=-6.33+63.12/2=25.23dBm

 The main contribution for t he
intremodulation is c oming from the IQmod.

48

Standard F ilter between
DAC1627D and BGX7100

300Mhz Chebychev Filter between DAC1627D and BGX7100

Refers to schematics PCB2227-1.0_17243\DOS_PCB2227-1.0_17243\ PCB2227-1-200-00_1_2.pdf
L101=L104= 39nH , L102=L105: 47nH, L103=L106 = 18nH C165= 10pf C166= 6.8pf
L107=L110= 39nH , L108=L111: 47nH, L109=L112 = 18nH C185= 10pF C186= 6.8pf

49

Filter response

50