Q&A - Recent Threads

MAX1231BETI+ 28pin TQFN-EP package thermal resistance

fbartraMissions — Mon, 13 Jul 2026 13:12:00 GMT

where can I find the thermal resistance for the MAX1231BETI+ 28pin TQFN-EP package?

it will be a lot easier if maxim products datasheets will include package drawings and thermal characteristics in the same document.

thank you

Fausto

is that power sequence between AVDD and VDD for ad4696?

xiaomage — Mon, 13 Jul 2026 12:01:57 GMT

hello everyone, i meet a problem when use AD4696, can some one help me?

1, I used AD4696 and FPGA for data acquirement

2, the VDD and VIO of AD4696 is powered by the same power supply which is 1.8V , and the AVDD is powered by a 5.3V , and RESET pin is pull-up to VIO by a resistor. the VIO of ad4696 and the VDD of FPGA is use the same power supply for the SPI databus communication

3, the problem is : when i power VDD/VIO first ,then power AVDD after 10ms, there will be data communication wrong probably; and when i power VDD/VIO and AVDD simultaneously, it work well .

4, there is no sequence requirement between VDD/VIO/AVDD in datasheet ,so why has this problem?

BTW: i wait long time to communicate the ad4696 after all power has done, when there is problem (communication wrong), i can't config the register of ad4696 by SPI, and it will probably work well when power down and power up again

EVAL-AD5941ELCZ Four Wire Impedance — Phase correct but Magnitude always NaN via crocodile cable

ClearwaveTech — Sat, 11 Jul 2026 17:51:49 GMT

Title: EVAL-AD5941ELCZ Four Wire Impedance — Perfect Phase but Magnitude Always NaN via Crocodile Cable (P6)

Body:

Hi EngineerZone community,

I'm using the EVAL-AD5941ELCZ with EVAL-ADICUP3029 running SensorPal v2.5.3.3 firmware. I'm trying to validate my setup before moving to biological tissue measurements for a medical device research project.

Setup:

Board: EVAL-AD5941ELCZ (Rev A)
Firmware: v2.5.3.3 (freshly updated)
Connection: Crocodile cable via P6 connector
Jumpers JP9, JP10, JP11 all set to position A
Test loads tried: 220Ω resistor, 10kΩ resistor, saline solution

Settings:

Mode: Four Wire Impedance
Start/Stop Frequency: 10kHz–100kHz
Amplitude: 10mV
RTIA: 200Ω
Rcal: 75Ω (matching onboard RCAL0 marked ED1)
PGA: GNPGA_2
Filter: Level 1.2, Hanning Window, DFT 8192

Symptoms:

Phase is consistently 0° (±0.2°) across all test loads ✅
Magnitude always returns NaN or 0.000 regardless of RTIA, Rcal, PGA, or amplitude settings
Graph shows real curve shapes with saline but magnitude won't compute
Tried RTIA values: 200, 1K, 5K, 10K, 20K, 40K, 80K, 160K
Tried Rcal values: 10, 20, 75, 100, 200, 10000

Questions:

What are the correct RTIA and Rcal settings for Four Wire Impedance via the P6 crocodile cable on the ELCZ board?
Does the crocodile cable path include isolation capacitors that would prevent pure resistor measurements?
Is there a known working configuration for SensorPal + ELCZ + crocodile cable for bioimpedance measurements in the 1kΩ–50kΩ range?

Any help appreciated. This is for a bioimpedance spectroscopy research project targeting pancreatic tissue characterization.

Note: RCAL0 on our board is marked ED1 (75Ω). Jumpers JP9, JP10, JP11 confirmed in position A.

Thank you

EVAL-AD2S1210SDZ: Excitation present but SIN/COS signal stuck at 0.1V

Adyaha — Sat, 11 Jul 2026 12:22:06 GMT

I'm using EVAL-AD2S1210SDZ Rev B with EVAL-SDP-CB1Z, connected to a resolver on a stepper motor shaft (separate unit, not integrated into motor). Resolver winding resistances: SIN = 74.4Ω, COS = 74Ω, EXC = 59.4Ω.

Wiring: Green→EXC_OUT, Purple→EXC_OUT return, Red→T_SIN, Black→T_SINLO, White→T_COS, Blue→T_COSLO.

Measurements (multimeter AC mode):

EXC_OUT to AGND: 5.3V AC (stable)
T_SIN to T_SINLO: 0.1V AC (no change with shaft rotation)
T_COS to T_COSLO: 0.1V AC (no change with shaft rotation)

Fault Register shows LOT (Loss of Tracking) and DOS (Degradation of Signal) constantly active. A, B, DIR LEDs blink green, indicating SPI communication with SDP-B is working.

Also facing a software issue: evaluation software shows this error on opening: "The VI is not executable. The full development version of LabVIEW is required to fix the errors." Running Windows 11.

Any help identifying the root cause would be appreciated. I've submitted 3 support cases (CS-588250-B3F5W3, CS-591607-P3S9Z1, CS-592523-N2S7D9) with no response for over a week.

Unexpected low-frequency (<100 Hz) result in SensorPal Three Wire Impedance mode using EVAL-AD5940ELCZ

NaufalA — Fri, 10 Jul 2026 10:11:50 GMT

Hello,

I am evaluating the EVAL-AD5940ELCZ using SensorPal and am testing the Three Wire Impedance measurement mode with a passive RC network.

I would like to understand whether this is expected, a configuration issue, or a limitation of the current SensorPal implementation.

Hardware
* EVAL-AD5940ELCZ
* SensorPal 2.5.3.2

Measurement Mode
* Three Wire Impedance

Measurement Settings
* Start Frequency: 175 kHz
* Stop Frequency: 1 Hz
* Amplitude: 100 mV
* Number of Points: 53 (Logarithmic)

* Power Mode: High Power
* Sample Rate: 10 SPS
* PGA Gain: GNPGA_1

* Internal RTIA: 10 kΩ
* Calibration Resistor: 10 kΩ

* Filter Level: Level 1.1
* Hanning Window: Enabled
* DFT Number: 16384

- Reference Electrode: CE0
- Counter Electrode: CE0
- Sense Electrode: SE0LOAD

Evalboard setup and connection
We use USB Connector and Cable to connect to the load. With JP6 disconnected

DUT:
The is a passive RC network consisting of a 10 kΩ series resistor followed by a parallel combination of a 10 kΩ resistor and a 100 nF capacitor.
Here are the schematic of the DUT/load

Expected Result from LT Spice Simulation
Bode Plot - Magnitude & Phase:

Nyquist Plot:

Observed Results
The measured impedance agrees well with the theoretical response at higher frequencies (approximately above 100 Hz).
However, below approximately 100 Hz, the measured impedance begins to deviate significantly from the expected response.
The error increases as the frequency decreases.

Bode Plot - Magnitude:

Bode Plot - Phase:

Nyquist Plot:

Question:
1. Is the AD5940 (or SensorPal's Three Wire Impedance implementation) expected to accurately measure a passive RC network down to 1 Hz using the configuration above?

2. Are there any known limitations of the Three Wire Impedance mode in SensorPal that affect measurements below approximately 100 Hz?

3. Are there recommended settings for low-frequency EIS that differ from the defaults, such as:
* Internal RTIA selection
* DFT Number
* Sample Rate
* Digital Filter Level
* Power Mode
* Excitation amplitude

4. Does SensorPal's Three Wire Impedance mode use the same measurement algorithm as the official AD5940/AD5941 EIS firmware examples, or does it implement a different measurement flow?

If this measurement should be achievable with the AD5940, I would appreciate any guidance on what configuration or hardware aspects should be investigated.

Thank you.

AD5941 Amperometric Measurement

VitoriaZilli — Tue, 07 Jul 2026 18:27:00 GMT

Hello,

I am working with the AD5941 to develop a device capable of performing amperometric measurements. For this purpose, I am using the example provided at: AD5940 Amperometric Example, running it on an NUCLEO-F030R8 board from ST Microelectronics.

As an initial validation step, I am performing measurements on a precision 10 kΩ resistor, which allows me to check whether the results are correct and compare them against a reference meter. My goal is to collect current readings every 0.1 s for at least 120 s. However, I am facing two issues:

When I set the FIFO threshold to a value greater than or equal to 3 (pAMPCfg->FifoThresh >= 3), the data read becomes inconsistent with the expected results.
Even when I set pAMPCfg->NumOfData to a fixed value (e.g., 1000), which should make the application acquire the specified number of points, the measurement stops after about 30 s. For example, with a 100 ms sampling interval, I only get around 300 points instead of the expected 1000. If I set pAMPCfg->NumOfData = 100, since the total acquisition time is shorter than 30 s, the measurement correctly stops at 100 points.

How could I modify the example to solve these problems? Which parameters might be interfering with these measurements?

I am available to provide any additional details if needed, and I appreciate any guidance.

Error budget calculation for AC signals

Andy79881 — Tue, 07 Jul 2026 13:01:03 GMT

Dear Team,

we are using the AD7616 to measure simultaneously AC voltages at two channels (A and B). The AC frequency range is from 300Hz upto 5kHz and the sampling frequency is 1MSPS. We are only interested in measuring the amplitude of the AC signal. The phase relationship is not important at all.

Q1: How can we calculate the mismatch between both channels for the AC signals. Datasheet specifies the SNR, SINAD, THD and dynamic range. For me it is not obvious, how to calculate the mismatch in mV or uV out of those parameters.

For the mismatch I would tend to use the negative fullscale error matching which is max. 12LSB for +/-10V range - but this is a DC performance parameter. Any help is appreciated.

Many thanks in advance.

Best Regards, Andreas

interfacing EVAL-AD5700-1EBZ

ruwaida — Mon, 06 Jul 2026 16:28:54 GMT

Hi, I am developing a Raspberry Pi 5-based HART communication prototype using the EVAL-AD5700EBZ evaluation board and a Yokogawa YTA610 temperature transmitter.

My goal is for the Raspberry Pi to act as the HART master, send a request to the YTA610, and receive the transmitter response through the AD5700 modem.

The current digital connections between the Raspberry Pi and the EVAL-AD5700EBZ are:

Raspberry Pi physical Pin 8 / GPIO14 TXD → J3 TXD
Raspberry Pi physical Pin 10 / GPIO15 RXD ← J3 RXD
Raspberry Pi physical Pin 11 / GPIO17 → J3 RTS
Raspberry Pi 3.3 V → J3 IOVCC
Raspberry Pi GND → J3 GND

I understand that the AD5700 labels TXD and RXD from the modem signal direction, so I connected Pi TXD to board TXD and Pi RXD to board RXD. Could you please confirm that this is correct?

24 V supply positive → YTA610 positive terminal

YTA610 negative terminal → 250 Ω resistor

250 Ω resistor → 24 V supply return

My uncertainty is the analogue HART connection at J2. I want to monitor or communicate on the existing 4–20 mA loop using the EVAL-AD5700EBZ. Could you please confirm the correct connection of:

J2 HART IN
J2 HART OUT
J2 GND

relative to the 250 Ω resistor and the transmitter loop?

In particular, should HART IN and HART OUT both be connected to the same transmitter-side node of the 250 Ω resistor, while J2 GND is connected to the supply-return side of the resistor? Or is a different coupling arrangement required?

For initial modem testing, I also tried a local full-duplex self-test with:

DUPLEX = B
24 V loop supply = OFF
YTA610 branch disconnected
250 Ω resistor retained as the local load

The Raspberry Pi sends a long UART preamble at:

1200 baud, 8 data bits, odd parity, 1 stop bit

RTS was measured successfully at approximately 0 V during transmit and 3.3 V during receive. The board IOVCC is approximately 3.3 V, and RESET is approximately 2.89 V.

However, during the local self-test:

CD remained low
No bytes were received on RXD

Could this result be caused by an incorrect J2 HART IN/HART OUT connection or missing external coupling circuit, rather than a faulty AD5700 board?

I have attached my current wiring diagram. I would greatly appreciate confirmation of:

The Raspberry Pi UART and RTS connections to J3.
The correct J2 HART IN, HART OUT, and GND connection to the 4–20 mA loop.
The correct local full-duplex self-test circuit for the EVAL-AD5700EBZ.
Whether any additional external components are required for this board to operate as a HART master interface.

Thank you.

Temperature Measurement Example Circuits

DavidTo — Wed, 01 Jul 2026 20:21:13 GMT

I need to add an external temperature sensor to a board using an AD4130-8. The user guide has links to thermistor, 2 wire RTD, 3 wire RTD and 4 wire RTD, among other things. Only the 4 wire RTD example is provided. The 4 wire circuit requires more channels than I have available so I am trying to find information on the other options. Can you provide this information or update the user guide to include them?

https://wiki.analog.com/resources/eval/user-guides/ad4130-8/softwareprocedures/demo_modes

Thanks

Requirement of a driver amplifier (AD829) for AD7655

ankit — Wed, 01 Jul 2026 01:16:16 GMT

Hi Team,

I am working on the following solution:

Optical Input --> PD (Photo-diode) --> read the value of PD using a logarithmic amplifier and AD7655.

I have two solutions regarding this:

Solution 1.

PD out (Photo-diode output) --> ADL5303 (Log Amp) --> AD829 (DriverAmp) --> AD7655 (ADC)

Solution 2. (bypassing driver amp)

PD out (Photo-diode output) --> ADL5303 (Log Amp) --> AD7655 (ADC)

I want to know which of the above solutions is better suited for the AD7655, and is bypassing the driver amplifier a good practice?

Lead Off Detection

GiovanniDeRosa — Mon, 29 Jun 2026 08:03:15 GMT

Hi, I'm using the ADAS 1000 and I'm having a problem detecting lead-off in both AC and DC.
Basically, only the RA, LA, and LL channels are connected to the connector. They are connected to the FLUKE Pulse 7000DP simulator.

Is it possible to detect lead off without the fourth electrode connected RDL?

LTC2311+DC890+DC2425

ADCcc — Fri, 26 Jun 2026 02:37:31 GMT

Hello,

I am evaluating the LTC2311-16 using the official DC2425A-A demo board and a DC890 controller.

Current setup:

* ADC: LTC2311-16

* Demo board: DC2425A-A

* Controller: DC890

* Software: PScope

* JP3 = DRIVE REFOUT

* JP10 = ON (on-board clock enabled)

* CMOS interface mode

I would like to evaluate the LTC2311-16 low-power operation, specifically:

1. Entering Sleep/Nap mode.

2. Waking up the ADC using SCK activity in CMOS mode.

3. Measuring REFOUT behavior during Sleep and Wake-up.

4. Measuring analog supply current (IVDD) and digital supply current (IOVDD) versus time during Sleep and Wake-up transitions.

My question is:

Can these tests be performed using only the DC890 + DC2425A-A platform and PScope software, or does the DC890 continuously generate CNV/SCK activity that prevents direct control of the Sleep/Wake-up sequence?

If DC890 is not suitable for this characterization, what is the recommended method to evaluate:

* Sleep current

* Wake-up time

* REFOUT recovery behavior

* IVDD and IOVDD transient current profiles

Would a custom FPGA or microcontroller interface be required instead of DC890?

Thank you for your help.

SENSORPAL ERROR TARGET NOT CONNECTED

Thirumeni — Wed, 24 Jun 2026 21:07:55 GMT

have ADICUP3029+ EVALAD5941BATZ boards, i am trying to measure impedance using Sensorpal software.

The software is installed, DAPlink appears in sensorpal and the new COM port (com5) visible in device manager of WIN10.

i update firmware and 100% completes, then it says remove and insert the usb, so once i do the same, later these error message appear...

UNABLE TO OPENCOMPORT....

Connection to com5 not estabished....

now green font

opening com port com5...

Reading version..

Error in Opening connectinn ...Invalid response from firmware...

How to solve this ....

DAPLINK is working and not FAIL.TXT file....

We connected Realterm terminal.. no output from ADICUP board.... but board blinking Red led while firmware is uploaded...

Do i need to upload any files from the gir AD5941 project... or everything is self contained in the Sensorpal...

in the sensor pal we selected Battery impedance...

Please help us.

Thanks

P Thirumeni

Measurement of a 49 V Battery pack below 1mOhm possible?

Silvan061 — Wed, 24 Jun 2026 16:09:31 GMT

Hello,

I am using the AD5941 within the CN-0510 reference design. So with EVAL-ADICUP3029 and EVAL-AD5941BATZ.

I have a series connection of 12 cells (49 V, 94 Ah) Each cell has a very low impedance at or under 1 mOhm.

Is it possible to measure the whole Battery pack with 12 cells in series with the Eval kits? I am a bit worried because of the 49V.

And is there a minimum the AD5941 can measure regarding the impedance? Or is it also possible to measure in mOhm ranges as long as the calibration resistor is small enough?

Thank you.

Silvan

Sensorpal and ADICUP3029 not communicating firmware error, DAPLINK ok, COM not connecting.

Thirumeni — Fri, 19 Jun 2026 07:02:24 GMT

Dear All,

I have ADICUP3029+ EVALAD5941BATZ boards, i am trying to measure impedance using Sensorpal software.

The software is installed, DAPlink appears in sensorpal and the new COM port (com5) visible in device manager of WIN10.

i update firmware and 100% completes, then it says remove and insert the usb, so once i do the same, later these error message appear...

UNABLE TO OPENCOMPORT....

Connection to com5 not estabished....

now green font

opening com port com5...

Reading version..

Error in Opening connectinn ...Invalid response from firmware...

How to solve this ....

DAPLINK is working and not FAIL.TXT file....

We connected Realterm terminal.. no output from ADICUP board.... but board blinking Red led while firmware is uploaded...

Do i need to upload any files from the gir AD5941 project... or everything is self contained in the Sensorpal...

in the sensor pal we selected Battery impedance...

Please help us.

Thanks

P Thirumeni

screenshot of errors..

Request for PCB design files for EVAL-ADAQ8092

engineer0167 — Thu, 18 Jun 2026 12:53:43 GMT

I am in the process of designing a board to interface between an FPGA development board and the EVAL-ADAQ8092.

I can find the schematic on the product page but am unable to find the PCB design files for the EVAL-ADAQ8092. There is a link at the bottom of the User Guide which supposedly directs you to "Board files" but returns "page not found".

Please could I have access to these design files / this link be fixed - thank you!

Designing an electrode grid for AD7147 to detect non-grounded dielectric objects

StanislavY — Tue, 16 Jun 2026 21:12:15 GMT

Hello ADI Support Community,

I am designing a small, tabletop machine that sorts 88x60x1mm paper cards using a computer vision system. The cards are handled and moved inside the machine using a vacuum suction cup mechanism.

Because there is a risk of a card dropping mid-process, my customer has requested a failsafe mechanism: if a card falls, the machine must immediately detect the dropped card and stop operation. To cover this scenario, I have come up with the idea of placing a 40x40cm PCB on the floor of the machine, mapped with a grid pattern of capacitive sensors using the AD7147.

Most of the CADC documentation, application notes, and user guides focus heavily on Human Body Model touch detection fig. 1, where a grounded finger draws charge away. My application is the exact opposite:

I need to detect a completely non-grounded, low-permittivity dielectric object (a paper card, relative permittivity ε ~ 2-3). The card will simply fall flat onto the floor (surface of the PCB).

figure 1

Since the target object (the paper card) is completely ungrounded, the detection mechanism cannot rely on a traditional charge-drain to ground. Instead, my idea is to layout a pattern of alternating electrodes: sensor pads interleaved with ground/shield pads (chess pattern or stripes). This will intentionally create a baseline parasitic capacitance via the fringing fields arching across the gaps between the electrodes and gnd.

When a card falls onto this grid fig 2:

It will physically bridge the gaps between adjacent traces.
The fringing electric field lines will penetrate the paper material instead of empty air.
Because the paper card has a higher relative permittivity than air, this change in the dielectric will increase the parasitic capacitance.

I don't need to know where the card is, so in theory one big electrode is sufficient, but i think that a lot of smaller electrodes will work better than single big one.

figure 2

My Questions:

Should I use an mutual capacitance grid layout across the channels, or a single-electrode (self-capacitance) pad layout?
How should the AD7147's active shield be integrated into a fringe-field layout for this purpose? Should it only be used as a bottom-layer shield?
Can i use several AD7147's on one board to increase electrode count? how the shields should be connected in such case?
Do you see any problem / risk of such design?
Any advice, reference layouts, or app notes regarding material/dielectric sensing rather than human touch with the AD7147 would be highly appreciated.

Thank you for your support.

EVAL-AD7124-8ASDZ 3-wire low-side RREF: excitation current mismatch (set 100 uA, measured different)

Saranya20491 — Sun, 14 Jun 2026 12:22:50 GMT

Hi Team,

I am testing AD7124-8 on EVAL-AD7124-8ASDZ and seeing an excitation current mismatch.

Setup:

EVK: EVAL-AD7124-8ASDZ
External connection: CN0383, Figure 21 (multiple 3-wire RTD, low-side RREF topology)
RTD replaced with fixed 100 ohm resistor
RREF = 4.7 kohm
Reference source = external REFIN1

Current firmware configuration:

Excitation current configured = 100 uA per IDAC
PGA gain = 8
Unipolar mode
Input/reference buffers enabled

CONFIG0 (0x19): 0x01E3
- bipolar=0, REF_BUFP=1, REF_BUFM=1, AIN_BUFP=1, AIN_BUFM=1, REF_SEL=REFIN1, PGA=8
FILTER0 (0x21): 0x000060
ADC_CONTROL (0x01): 0x0000 (continuous mode defaults, internal REF_EN disabled)
ERROR_EN (0x07): 0x000800 (REF_DET_ERR_EN)

Channel assignments in code:
- CHANNEL_0 (0x09) = 0x8043 (AIN2/AIN3)
IDAC routing table in code:

RTD1: IDAC1->AIN0, IDAC2->AIN1.

When configured for 100 uA, measured current is about 160 uA. I measured current by inserting ammeter in series between IOUT0 node (AIN0) and RTD lead to measure source branch current.

Are there EVK jumper/switch settings that can cause this behavior?

Get Variation in signal

Surender — Thu, 11 Jun 2026 11:13:58 GMT

Our 1mV to 80mV differential signal connect to R104 & R105, Our signal is stable before of R341 & R342, but signal get varied upto 3-5mV after these resistor, IRP_M+ & IRP_M- connect to MCU, We've checked it after removing MCU also, but signal get varied, R326 is connected & REF_CT is 0.632V.

RE: Simulation Spice model for AD654

Jayapal — Mon, 08 Jun 2026 04:54:45 GMT

Hope long shut down is over. Could you provide Spice model for AD654 and equivalent IC for AD654

Resisitor to evaluate baord testing connections-- 2 wire bioz measurement

brady1 — Tue, 02 Jun 2026 04:50:34 GMT

Hi, I am wondering if this is the appropriate way of connecting resistors to the eval board when trying to test measurements. I have a differnt version of the board so i am unable to reference previous examples. Please could you confirm?drive.google.com/.../view

drive.google.com/.../view

Use of the RAM and SYNC_SPI registers on the MAX11284

bluespider — Thu, 28 May 2026 12:10:59 GMT

The datasheet does not document the use of the RAM and SYNC_SPI registers, only giving "Address Space Only, Not a Physical Register. Please contact factory for instructions on using internal RAM function".

AD7124-can be used for 16 channels sequential or not

ckhaw772 — Thu, 28 May 2026 02:45:11 GMT

Dear Sir, look at AD7124-8 and need 16 channels and not required simultaneously.
would like to confirm for this IC can be used as 16 channel single-ended ADC with sequential or not?
According to the datasheet, AINM[4:0] can be set to AVss,
so by theory, can have all 16 AI channel be selected as AINP with reference to AVss as AINM and become 16 single-ended. How's about practical, is it working on it. Please advise. Thank you,

Having an issue getting the encoder output resolution to latch in normal mode when using serial communications with the AD2S1210

bissingerr — Wed, 27 May 2026 20:10:01 GMT

I am working on an Arduino IDE sketch that utilizes an Arduino Portenta H7 unit communicating with an AD2S1210 RDC module built by ZonRi Tech. I have been able to successfully write and read the various registers in CONFIG mode as shown in the serial output below:

15:43:15.310 -> Hardware Reset Complete
15:43:15.843 -> LOS (0x88): 0x39 expected: 0x39
15:43:15.843 -> DOS_OVR (0x89): 0x6C expected: 0x6C
15:43:15.886 -> DOS_MIS (0x8A): 0xA expected: 0xA
15:43:15.886 -> DOS_MAX (0x8B): 0x3D expected: 0x3D
15:43:15.886 -> DOS_MIN (0x8C): 0x69 expected: 0x69
15:43:15.886 -> LOT_HI (0x8D): 0x23 expected: 0x23
15:43:15.886 -> LOT_LO (0x8E): 0x8 expected: 0x8
15:43:15.886 -> FREQ (0x91): 0x21 expected: 0x21
15:43:15.886 -> CTRL (0x92): 0x7B expected: 0x7B
15:43:15.886 -> CTRL (0x92): 0x7B
15:43:15.886 -> Digital Position Resolution: 65536
15:43:15.886 -> Encoder Resolution: 16384
15:43:16.392 -> AD2S1210 Init Complete
15:43:16.902 -> Pos: 0xFE53 Deg: 357.64 Duty: 0.066 Cnt: 65107 FB10: 0.000 Flt: 0x10
15:43:16.992 -> Pos: 0xFE53 Deg: 357.64 Duty: 0.066 Cnt: 65107 FB10: 0.632 Flt: 0x10

The Hardware reset toggles the RESET pin and I see the excitation outputs shift to the default running frequency (12kHz - CLKIN is 10kHz) and both the digital outputs and the encoder outputs defaults to 14bit and 16bit as expected by the default control register value of 7E. I have hard wired RES0 and RES1 to +Vcc so that the digital outputs run at 16bit resolution in normal mode.

I would like to set the encoder outputs to 14bit in NORMAL mode, and it looks like the CTRL register write sticks, and can be sub-sequently read to show the expected target value. However, when I shift back into NORMAL mode, my encoder outputs drop to 1024 resolution. Not sure what is happening here. The 24 bit read function works great to measure position and the serial polling shows I am reading 16bit resolution on the digital outputs.

My sketch is included in the following file:

ez.analog.com/.../Resolver-Sketch-_2D00_-260527C.txt

My guess is that I am missing something simple...

Unable to read via F8379D SPI interface

SumeetST — Wed, 27 May 2026 14:25:20 GMT

Hi,

I have connected all the necessary pins for SPI fron F28379D launchpad to CN0276 using J2.

I was not getting any data, I then connected the /CS to gound by replaciong R57 from 10k to 0ohm.

After instead of 0 and I get 0xFF as read values for all resgister.

I have checked the ground connections and the clock & FSYNC signals they work correct. However I see very low pulses of data on SDI and SDO is always high (with some pulses which dont change beyond threshold voltage).

I am struggling to make this work? Do we need to make any other changes to CN0276 board? do we need to tie VDrive of AD2S1210 to 3.3V of MCU? (if yes, how)

Is there any additinal help material or sample code to try out?

thanks

Sumeet