Forum - Recent Threads

RE: Support required for HMC356LP3ETR Low-Noise Amplifier

jc2048 — Thu, 26 Mar 2026 08:47:09 GMT

What is the "issue"?

The datasheet says the pins labelled as GND should be connected to RF/DC ground. It doesn't say they're all connected inside the device.

The resistance you measure between 6 and 7 is the bias for the FET. You'd expect to see it there. Presumably you've connected a decoupling capacitor to 7 and not a GND in your circuit. If you've connected a ground to 7, you'll get whatever the FET current is with the gate at 0V, instead of the 100mA or so at their dc bias point (don't leave it running like that - I doubt the package can manage the dissipation: it probably gets fairly warm even at the 100mA).

2, 4, and 16 are dummies that you can use to run the surface ground into the paddle area - 2 and 4 allow you to bring the transmission line all the way in without a discontinuity. 16 is to run a ground in alongside the vdd to improve the decoupling performance (the return current has to get across to 6). The designer is just steering you as to how they thought the layout would work.

The paddle will be the substrate connection, which you'll probably want to heatsink with vias down to the plane. I would guess the input termination goes down to the paddle, that would seem to make most sense, but I'm not very familiar with this kind of stuff - it might go to GND at 6.

The chip designer seems to have intended the copper under the paddle to be the common point between input and output.

What's interesting is that the 3rd party who designed the evaluation board have done the layout in a different way, isolating the paddle on the surface layer and using the plane for everything. I would assume they know what they're doing, so it would be interesting to know the pros and cons of the two approaches.

Disclaimer: I've never done any RF, so decide for yourself if this makes any sense. I do have vague memories of how a FET works, though (retired engineer!).

Support required for HMC356LP3ETR Low-Noise Amplifier

alphaise — Wed, 25 Mar 2026 07:33:21 GMT

During probing of the IC, we observed that pins 6 (GND) and 7 (ACG) are shorted together, and are also shorted to pin 15 (Vdd). However, the other GND pins (ground paddle, pins 2, 4, and 16) do not appear to be shorted together.

This issue was observed consistently in 2 units that were tested. For reference, I have attached the pinout diagram and a top-view image of the IC.

RE: Support required for HMC356LP3ETR Low-Noise Amplifier

alphaise — Thu, 26 Mar 2026 02:56:27 GMT

The issue is consistent both before and after applying power.

The parts were purchased from Element14 (Singapore), and they had sent over replacement units after I alerted them of the issue - but the shorting is still present (i.e., no change).

I used the continuity test on various multimeters for measurements. The resistance between pin 15 (Vdd) and 6 (GND) is about 8.1 Ω, and 2.9 Ω between pin 15 and 7 (ACG).

RE: Support required for HMC356LP3ETR Low-Noise Amplifier

alphaise — Thu, 26 Mar 2026 02:48:20 GMT

Yes, I checked against the chamfered edge on the ground paddle as well.

RE: Support required for HMC356LP3ETR Low-Noise Amplifier

Jan Cumps — Wed, 25 Mar 2026 18:47:53 GMT

Did you use the dot as pin1 indicator?

RE: Support required for HMC356LP3ETR Low-Noise Amplifier

michaelkellett — Wed, 25 Mar 2026 09:04:43 GMT

Is this before or after you had applied power ?

Where did you buy the parts ?

How are you measuring them - when you say "shorted" what do you mean - is it the same resistance in either polarity, what is that resistance.

Urgent Support is required for EVAL-AD9984AEBZ

neerajrd82 — Tue, 30 Dec 2025 00:14:00 GMT

I m writing the issue observations in a clear and structured manner given below:

1. We have interconnected EVAL-AD9984AEBZ board with our test bench as given below:

2. We first switch "ON" RGsB video generator source. Then changed the settings on VESA complaint Sync on Green Analog signal with 1600x1200 pixels at 60 Hz.

3. We checked RGsB display, if this display is working correctly. We found that above shown RGsB Display was actually showing Sync on green signal. Now, we can actually change the resolution of Sync on green video signal.

4. We connected EVAL-AD9984AEBZ to CPU using USB cable provided -> this made USB PWR LED (D7) glow onboard & switch "ON" the EVAL-AD9984AEBZ board using AC to DC adapter provided with board -> this made main power LED (D6) glow on board.

5. Now, we loaded AVES Blue & selected the connection tab. Thereafter, double clicked on CY7C68013 which actually connect this board with Windows based PC.

6. We added "AD9984A-VER.1.0c.txt" script in AVES Blue which gives us the options given below:

Out of these, we have selected "162MHz 60Hz UXGA(1600x1200)". Now, this settings will load default settings for AD9984A & ADV7511 as recommended by ADI.

Now, HDMI Display connected with this evaluation board gets refresh just for second & then goes into sleep mode displaying nothing at all.

Upon loading AD9984.xml file in AVESBlue, we get these answers on loading settings from AD9984 given below:

PLL of AD9984 is getting locked can be seen in above screenshot.

Please note: Given below procedure is not written in the documentation of EVAL-AD9984AEBZ but still we have managed to monitor the functioning of ADV7511.

Upon loading ADV7511.xml file in AVESBlue, we get these answers on loading default settings from ADV7511 given below:

PLL of ADV7511 is not getting locked can be seen in above screenshot.
Since PLL of ADV7511 is not getting locked, there is no picture on HDMI output.

these are default settings given by Analog Devices:

98 00 01 ; Chip revision
98 01 87 ; PLL Div
98 02 00 ; PLL Div
98 03 F0 ; VCO range, Charge pump current
98 04 E0 ; VCO range, Charge pump current
98 05 00 ; Red Gain
98 06 80 ; Red Gain
98 07 00 ; Green Gain
98 08 80 ; Green Gain
98 09 00 ; Blue gain
98 0A 80 ; Blue gain
98 0B 00 ; Red offset
98 0C 80 ; Red offset
98 0D 00 ; Green offset
98 0E 80 ; Green offset
98 0F 00 ; Blue offset
98 10 80 ; Blue offset
98 11 20 ; Sync separator
98 12 00 ; Hsync
98 13 20 ; Hsync duration
98 14 04 ; Vsync
98 15 0A ; Vsync duration
98 16 04 ; precoset
98 17 04 ; postcoast
98 18 00 ; clamping
98 19 08 ; clamp placement
98 1A 14 ; clamp duration
98 1B 33 ; clamp polarity
98 1C FF ; ADI recommended write
98 1D 78 ; sync on green
98 1E 34 ; Input channel select
98 1F 93 ; Output video mode
98 20 07 ; Output impedance
98 21 20 ; ADI recommended write
98 22 32 ; ADI recommended write
98 23 14 ; sync filter window width
98 24 A8 ; sync detect
98 25 FD ; sync polarity
98 26 4E ; Hsync per vsync
98 27 20 ; Hsync per vsync
98 28 8F ; ADI recommended write
98 29 02 ; ADI recommended write
98 2A 00 ; ADI recommended write
98 2B 00 ; ADI recommended write
98 2C 00 ; ADI recommended write
98 2D 08 ; ADI recommended write
98 2E 20 ; ADI recommended write
98 3C 0E ; Auto gain
72 01 00 ; Set 'N' value at 6144
72 02 18 ; Set 'N' value at 6144
72 03 00 ; Set 'N' value at 6144
72 15 00 ; 24-bit, 444 RGB input
72 16 50 ; RGB
72 18 08 ; Disable CSC
72 17 01 ; Enable DE Generation
72 35 7B ; DE Generation
72 36 F0 ; DE Generation
72 37 0C ; DE Generation
72 38 80 ; DE Generation
72 39 4B ; DE Generation
72 3A 00 ; DE Generation
72 3B 40 ; Set Pixel Repetition
72 3C 00 ; Set VIC
72 40 80 ; General control packet enable
72 41 10 ; Power down control
72 49 A8 ; Set dither mode - 12-to-10 bit
72 4C 05 ; Set 10 bit output
72 96 20 ; HPD interrupt clear
72 55 00 ; Set to RGB
72 56 08 ; Set active format aspect
72 98 03 ; ADI recommended write
72 99 02 ; ADI recommended write - lock count limit
72 9C 30 ; PLL filter R1 value
72 9D 61 ; Set clock divide
72 A2 A4 ; ADI recommended write
72 A3 A4 ; ADI recommended write
72 AF 16 ; Select HDMI mode
72 BA A0 ; Set TX Clock Delay
72 DE 9C ; ADI recommended write
72 E4 60 ; VCO_Swing_Reference_Voltage
72 FA 7D ; Nbr of times to look for good phase
72 48 00 ; Evenly distrubuted output
72 55 10 ; RGB out
72 56 00 ; Set AVI
72 57 00 ; Adobe RGB

While debugging the reasons of misbehaviour of this board, we found that HSOUT,VSOUT & DATACK output from AD9984a was not compliant as per standard VESA timing for 1600x1200 pixel at 60 Hz sync on green with help of good quality 350MHz oscilloscope. These 3 signals were not stable, there was jitter in all 3 signals.

So, we decided to stabilized the waveform by changing the settings of following registers:

CHIP REGISTER SETTINGS

AD9984A 0x12 0x48

AD9984A 0x13 0xC0

AD9984A 0x14 0x0C

AD9984A 0x1D 0xB8

AD9984A 0x34 0xB4

ADV7511 0x41 0x00

These settings stabilized all 3 signals as per VESA timing standards for 1600x1200 pixel at 60Hz SoG.

We were able to secure the PLL lock of ADV7511 as result of above settings as per screenshot given below:

but still there was no picture output on HDMI Display shown above.

Now, I sincerely think that all of whom are accessing this, should be able to understand the how we are able reproduce the failure of this board.

if experts are able to understand this procedure ?

Kindly! help on urgent basis as this is critical problem. Since i m not getting any support.

THANKS WITH REGARDS

NEERAJ GUPTA

Have a technical question for Maxim? Ask an Expert!

nlarson — Fri, 30 Oct 2009 19:24:35 GMT

If you need help on anything technical relating to Maxim products, please post your question here!

Don't forget to sign up for email notifications under the "Actions" box so you'll see when Andy answers your question.

[View:/resized-image/__size/300x107/__key/communityserver-discussions-components-files/44/contentimage_5F00_131171.jpg:300:107]

Andy Waller

Andy is an Applications Engineer with Maxim Integrated Products. He specializes in technical support for Maxim's product range for the entire life cycle of a product - from design to field..

If not already, you'll need to

[View:/resized-image/__size/300x300/__key/communityserver-discussions-components-files/44/contentimage_5F00_2208.png:300:300] or [View:/resized-image/__size/300x300/__key/communityserver-discussions-components-files/44/contentimage_5F00_2252.png:300:300]

to ask your question.

Otherwise, click reply below.

RE: Have a technical question for Maxim? Ask an Expert!

svanderwolf — Tue, 16 Sep 2025 09:48:52 GMT

Please contact our EngineerZone for assistance: https://ez.analog.com/.

RE: Have a technical question for Maxim? Ask an Expert!

michaelkellett — Tue, 16 Sep 2025 09:40:37 GMT

Bob - there has been no activity in this thread in the last 15 years.

Might be worth making enquiries direct to Analog Devices (who own Maxim).

RE: Have a technical question for Maxim? Ask an Expert!

BobJapenga — Mon, 15 Sep 2025 22:08:58 GMT

I am a retired embedded design engineer with 50 years of electronics experience. I am intterested in developing a product around the MAX86140 using the MAX-HEALTH-BAND. I have read the guide and the data sheet and watched the video - but there are still many more questions I have. I have not found the full cadre of documentation yet. I want to ascertain if the MAX86140 can do what I want it to do. Thanks in advance.bbb

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

Jan Cumps — Sat, 02 Aug 2025 21:30:23 GMT

I checked, and this module has the deadband circuitry built-in. All good.

Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

dfansler — Fri, 01 Aug 2025 18:29:41 GMT

Hi Andy -

I had my DS1050-025 running, for a while, but now I can only get about 3 to 10 cycles out it. I have gone back over changes I have made, but nothing seems to help. Here is the test code I am currently trying. I open the DS1050 i2c, using address 0x28 ( as shown by i2cdetect on my Raspberry Pi, which this hardware is on). Then I write 0x50 (set PMW command) followed by the data (shown as 0x10h - which should be 50% PWM).

I close the file descriptor, call the second function, where I open the DS1050 in i2c again, writing 0x50 (set PWM command) followed by the data 0x20 as shown on the DS1050 data sheet. Then again close the file descriptor. I have tried combining the two functions and write 0x50, 0x10, 0x50, 0x20 and the close i2c with the same results.

[embed:dc8ab71f-3b98-42d9-b0f6-e21e02a0f8e2:6cce3947-173e-4f66-8149-dbeab8d0fb0a:type=text&text=%23include%20%3Cstdio.h%3E%0D%0A%23include%20%3Cstdlib.h%3E%0D%0A%23include%20%3Cmath.h%3E%0D%0A%23include%20%22%2Fhome%2Fdvf%2Fglg%2Finclude%2FGlgApi.h%22%0D%0A%23include%20%3Csys%2Ftypes.h%3E%0D%0A%23include%20%3Csys%2Fstat.h%3E%0D%0A%23include%20%3Cfcntl.h%3E%0D%0A%23include%20%3Cunistd.h%3E%20%20%20%20%2F%2F%20read%2Fwrite%20usleep%20%20%20%20%20%0D%0A%23include%20%3Cinttypes.h%3E%20%20%2F%2F%20uint8_t%2C%20etc%0D%0A%23include%20%3Clinux%2Fi2c-dev.h%3E%20%2F%2F%20I2C%20bus%20definitions%0D%0A%23include%20%3Csys%2Fioctl.h%3E%09%09%09%2F%2FNeeded%20for%20I2C%20port%0D%0A%23include%20%22%2Fhome%2Fdvf%2Fglg%2Finclude%2FGlgApi.h%22%0D%0A%23include%20%3Csys%2Fsocket.h%3E%0D%0A%23include%20%3Cnetinet%2Fin.h%3E%0D%0A%23include%20%3Cstring.h%3E%0D%0A%23include%20%3Carpa%2Finet.h%3E%0D%0A%0D%0A%0D%0A%23include%20%3Ctermios.h%3E%0D%0A%0D%0A%23include%20%3Cstdio.h%3E%0D%0A%23include%20%3Csys%2Ftypes.h%3E%20%2F%2F%20open%0D%0A%23include%20%3Csys%2Fstat.h%3E%20%20%2F%2F%20open%0D%0A%23include%20%3Cfcntl.h%3E%20%20%20%20%20%2F%2F%20open%0D%0A%23include%20%3Cunistd.h%3E%20%20%20%20%2F%2F%20read%2Fwrite%20usleep%0D%0A%23include%20%3Cstdlib.h%3E%20%20%20%20%2F%2F%20exit%0D%0A%23include%20%3Cinttypes.h%3E%20%20%2F%2F%20uint8_t%2C%20etc%0D%0A%23include%20%3Clinux%2Fi2c-dev.h%3E%20%2F%2F%20I2C%20bus%20definitions%0D%0A%23include%20%3Csys%2Fioctl.h%3E%0D%0A%23include%20%22PWM.h%22%0D%0Aint%20PWM_Write2%28void%29%3B%0D%0Aint%20fd_pwm%2C%20fd%3B%0D%0A%20%20%20int16_t%20val%3B%0D%0A%20%20%20uint8_t%20writeBuf%5B5%5D%2C%20readBuf%5B2%5D%3B%0D%0A%0D%0Avoid%20main%28void%29%0D%0A%7B%0D%0A%20%20%20%0D%0A%0D%0A%20%20%20%2F%2F%20open%20device%20on%20%2Fdev%2Fi2c-1%20%0D%0A%20%20%20if%20%28%28fd_pwm%20%3D%20open%28%22%2Fdev%2Fi2c-1%22%2C%20O_RDWR%29%29%20%3C%200%29%20%0D%0A%20%20%20%7B%0D%0A%20%20%20%20%20%20printf%28%22Error%3A%20Couldn%27t%20open%20I2C%20device%5Cn%22%29%3B%0D%0A%20%20%20%20%20%20return%3B%0D%0A%20%20%20%7D%0D%0A%0D%0A%20%20%20%2F%2F%20connect%20to%20ads1115%20as%20i2c%20slave%0D%0A%20%20%20if%20%28ioctl%28fd_pwm%2C%20I2C_SLAVE%2C%20PWM_Addrs%29%20%3C%200%29%0D%0A%20%20%20%20%7B%0D%0A%20%20%20%20%20%20printf%28%22Error%3A%20Couldn%27t%20find%20device%20on%20address%21%5Cn%22%29%3B%0D%0A%20%20%20%20%20%20return%3B%0D%0A%20%20%20%7D%0D%0A%20%20%20%2F%2F%20set%20config%20register%20and%20start%20conversion%0D%0A%0D%0A%20%20%20writeBuf%5B0%5D%20%3D%20SetPWM%3B%20%20%20%20%2F%2F%20config%20register%20is%201%0D%0A%20%20%20writeBuf%5B1%5D%20%3D%200x10%3B%0D%0A%20%20%2F%2F%20Set%20newm%20PWM%20duty%0D%0A%20%20%20if%20%28write%28fd_pwm%2C%20writeBuf%2C%204%29%20%21%3D%204%29%20%0D%0A%20%20%20%7B%0D%0A%20%20%20%20%20%20%20printf%28%22Can%27t%20write%20to%20register%201%5Cn%22%29%3B%0D%0A%20%20%20%20%20%20%20return%3B%0D%0A%20%20%20%7D%0D%0A%0D%0A%20%20%20close%28fd_pwm%29%3B%0D%0A%0D%0A%20%20%20PWM_Write2%28%29%3B%0D%0A%20%20%20while%281%29%0D%0A%7B%0D%0A%20%20%20%3B%0D%0A%7D%0D%0A%0D%0A%7D%0D%0A%0D%0Aint%20PWM_Write2%28void%29%0D%0A%7B%0D%0A%20%20%20%2F%2F%20open%20device%20on%20%2Fdev%2Fi2c-1%20%0D%0A%20%20%20if%20%28%28fd%20%3D%20open%28%22%2Fdev%2Fi2c-1%22%2C%20O_RDWR%29%29%20%3C%200%29%20%7B%0D%0A%20%20%20%20%20%20printf%28%22Error%3A%20Couldn%27t%20open%20I2C%20device%5Cn%22%29%3B%0D%0A%20%20%20%20%20%20return%201%3B%0D%0A%20%20%20%7D%0D%0Aprintf%28%22fd%20%3D%20%25d%5Cn%22%2Cfd%29%3B%0D%0A%20%20%20%2F%2F%20connect%20to%20ads1115%20as%20i2c%20slave%0D%0A%20%20%20if%20%28ioctl%28fd%2C%20I2C_SLAVE%2C%20PWM_Addrs%29%20%3C%200%29%20%7B%0D%0A%20%20%20%20%20%20printf%28%22Error%3A%20Couldn%27t%20find%20device%20on%20address%21%5Cn%22%29%3B%0D%0A%20%20%20%20%20%20return%201%3B%0D%0A%20%20%20%7D%0D%0A%2F%2F%20set%20config%20register%20and%20start%20conversion%0D%0A%0D%0A%20%20%20writeBuf%5B0%5D%20%3D%20SetPWM%3B%20%20%20%20%2F%2F%20config%20register%20is%201%0D%0A%20%20%20writeBuf%5B1%5D%20%3D%200x20%3B%0D%0A%20%20%20%2F%2F%20Set%20newm%20PWM%20duty%0D%0A%20%20%20if%20%28write%28fd%2C%20writeBuf%2C%202%29%20%21%3D%202%29%20%0D%0A%20%20%20%7B%0D%0A%20%20%20%20%20%20%20printf%28%22Can%27t%20write%20to%20register%201%5Cn%22%29%3B%0D%0A%20%20%20%20%20%20%20return%201%3B%0D%0A%20%20%20%7D%0D%0A%0D%0A%09close%28fd%29%3B%0D%0A%7D%0D%0A]

Hope you can help,

David
YouTube "Sailing Solo at 70"

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

dfansler — Sat, 02 Aug 2025 20:12:46 GMT

Thanks I appreciate it!

David

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

dfansler — Sat, 02 Aug 2025 20:12:11 GMT

It is just a generic unit from Amazon. Dual Motor Controller, 12v, 30A per Channel. Each channel has Gnd, Pwr, In1, In2, Enable and a current output that is CT Output Voltage (V) = Current (A) x 0.155 . Found out more about it (current per channel and CT from another website. I have used it on small motors with inverted PWM signal with no problem.

David

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

beacon_dave — Sat, 02 Aug 2025 17:21:42 GMT

[quote userid="482948" url="~/products/manufacturers/analog-devices/f/forum/56018/cannot-maintain-a-constant-pwm---only-get-about-10-cycles-out-of-my-ds1050-025/229867"]I am headed out this week to find and raise Dragon Fire.[/quote]

I hope that goes well for you.

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

Jan Cumps — Sat, 02 Aug 2025 12:16:25 GMT

[quote userid="482948" url="~/products/manufacturers/analog-devices/f/forum/56018/cannot-maintain-a-constant-pwm---only-get-about-10-cycles-out-of-my-ds1050-025/229867"]my motor controller requires two PWM signals that are the inverse of each other[/quote]

What controller are you using? Some require dead time between the edges of the two opposite signals.

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

dfansler — Sat, 02 Aug 2025 11:56:57 GMT

Hi Andrew and Dave - thanks for your comments.

The cyan trace is in inverse of the yellow trace - my motor controller requires two PWM signals that are the inverse of each other.

I see the problem now - when you look at the data sheet on page 11, the first command (a) is to SetPWM, the second command (b) has no label and I thought it was a continuation of the SetPWM command, since the rest of the commands have labels!

I dropped the second command and all is well - the PWM works as expected.

Many thanks for the help.

The PWM is part of an autopilot I am building for my 24' cuddy cabin boat "Dragon Seeker". The USCG sank my 50' sailboat (Dragon Fire) some 15 miles off the coast of Virginia Beach, VA. I am headed out this week to find and raise Dragon Fire. Once up, I will be using Dragon Seeker to push Dragon Fire about 70 miles south in the Atlantic to Oregan Inlet and then some 90 miles to a boat yard near Washington, NC. The autopilot will allow me to do work on Dragon Fire while underway, AND keep me from having to steer Dragon Seeker manually for the trip - which will probably take 2 to 3 days. You can see the out come on YouTube at "Sailing Solo at 70" (although I am 74 now). I purchased Dragon Fire in Greece in 2022 and sailed it solo from Greece to North Carolina.

Again, thanks for the help.

David

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

Andrew J — Sat, 02 Aug 2025 09:59:56 GMT

Trace 2, cyan, shows the start of something that coincides with the drop from 100%. Is it reasonable to assume the two are connected, trace of SCL perhaps? I expect the LA trace was taken at a different time to the scope trace but it would be useful to see it synchronised across the problem. However, it would be good for the OP to come back with more info as to what he/she expects to see.

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

beacon_dave — Sat, 02 Aug 2025 09:41:50 GMT

If you look at the scope trace, it transitions from 50% to 100% as per the commands but then after around 450us it transitions to 0%. The logic analyser capture stops before it transitions to 0% so can't see if there was another command sent or not to cause this.

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

Andrew J — Sat, 02 Aug 2025 09:36:36 GMT

Ah ok, makes sense. That is shown in the logic analyser output so it looks like all is working.

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

Jan Cumps — Sat, 02 Aug 2025 09:14:18 GMT

Once you have the problem here solved, I'd be interested in reading about your experience with the analyzer.

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

beacon_dave — Sat, 02 Aug 2025 09:09:49 GMT

0x20 is the command to "Set PWM duty cycle 100%"

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

Andrew J — Sat, 02 Aug 2025 09:05:44 GMT

The few you are seeing are probably the result of sending the 50% PWM command which is then arrested by sending the 0x20 byte value. At a guess!

RE: Cannot maintain a constant PWM - only get about 10 cycles out of my DS1050-025

Andrew J — Sat, 02 Aug 2025 09:03:45 GMT

Perhaps I’ve missed something but you are sending 0x20 as data which is 0b00100000 but the data byte only allows for 5 bits (which are all 0). If you look at page 11 of the data sheet, sending 0b00100000 tells the device to ignore the data bits (it’s effectively a NOP command). What is the data value you are actually trying to send?