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Old 19th March 2021, 07:55 PM   #471
syn08 is offline syn08  Canada
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Ok, DAC is coming up... PCB (4 layers, 3.9"x3.7", top layer is shown, solid ground plane, power plane, routing plane) is in the final stage @JLCPCB, will get the boards next week. ES9038PRO are also coming from Mouser (they re-stocked the chips). PCB screenshot below.

- Top side row: +/-15V and +1.65V (LT3045 and LT3094) for the IV stages, plus the power sequencing circuitry (based on LTC2924)
- Top left corner, room for an 100MHz clock (the "horrible" Si570, I wonder about the difference between having both the ADC and the DAC synchronized, and having the DAC to run by it's own clock with high oversampling rate)
- Left column, digital inputs, SMA
- 2 ES9038PRO in mono mode.
- Mid row, analog power supplies, 3.3V, 1.2V based on the ADM7154 chips
- Left of the DAC chips, in a column, the digital power supplies, 3.3V, 1.2V, based on the LP5907 chips.
- Between the digital inputs and the power supplies, digital buffers and distribution, based on the LMK1C1102 chips.
- Right of the DAC chips, the I/V stages and reconstruction filters, 4 x OPA1622 (dials, for their high output current capability) plus 4x OPA1655 summing amplifiers.
- Right edge, analog differential outputs, SMA.
- Bottom left corner, more power digital power supplies (buffers, Si570 PLL, etc...) and the I2C interface connector (controls the DAC chips and the Si570).

Hope to have some measurements results in a couple of weeks... Then the XMOS digital integration and the input analog stages (with autoranging).

BTW, don't ask me how I learned, but the interesting schematic https://www.analog.com/media/en/tech...ets/LT3094.pdf page 30 is on the bench a silicon graveyard. Both the LT8582 and the LT3045 are destroyed at the first power up, I've burned $100 in chips while experimenting. Still don't know exactly why it does this, but I assume is the missing P-Channel MOSFET on the positive rail. Per the LT8582 datasheet, this MOSFET allows the positive rail soft start, without this the LT8482 blows (since the control voltage from the LT3045 doesn't have a chance to settle and the converter is in full throttle until it would), and the spikes take out the LT3045 as well. It's a shame LT/AD pushed such an unverified (on the bench) schematic in the LT3094 data sheet.
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Last edited by syn08; 19th March 2021 at 08:01 PM.
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Old 19th March 2021, 10:20 PM   #472
bohrok2610 is offline bohrok2610  Finland
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Originally Posted by syn08 View Post
BTW, don't ask me how I learned, but the interesting schematic https://www.analog.com/media/en/tech...ets/LT3094.pdf page 30 is on the bench a silicon graveyard. Both the LT8582 and the LT3045 are destroyed at the first power up, I've burned $100 in chips while experimenting. Still don't know exactly why it does this, but I assume is the missing P-Channel MOSFET on the positive rail. Per the LT8582 datasheet, this MOSFET allows the positive rail soft start, without this the LT8482 blows (since the control voltage from the LT3045 doesn't have a chance to settle and the converter is in full throttle until it would), and the spikes take out the LT3045 as well. It's a shame LT/AD pushed such an unverified (on the bench) schematic in the LT3094 data sheet.
This is quite surprising since AD has published some measurements and thermal images of the same dual power supply (Negative Linear Regulator Features 0.8 mV RMS Noise and 74 dB Power Supply Rejection Ratio at 1 MHz | Analog Devices). Maybe you should ask Molly for help
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Old 19th March 2021, 11:27 PM   #473
syn08 is offline syn08  Canada
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Maybe I'm doing something wrong, one difference is I tried to feed this dual boost arrangement from +5V (instead of +12V, with all the inductors and capacitors re-calculation, per the data sheet). Once I will try again, for now I'm sick of burning rather expensive ICs.
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Old 21st March 2021, 12:34 PM   #474
capslock is offline capslock  Europe
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Originally Posted by 5th element View Post
Actually anyone can order from ISMOsys and the price is per unit. I had 4 ES9822 Pro arrive this morning and they took about a week to get here from the date they were ordered. I too was surprised at how cost effective these ADCs are given their reputed performance.

Whether or not you are eligible to sign an NDA for the data sheets is another thing but that's up the people at ESS. It doesn't hurt to try. If you have a company email/name or website, of your own, you can go through that would make it easier.

I was surprised to see some of the ESS dacs turn up as mouser, including the data sheet and no NDA fuzz, they were just there to download. No adcs yet...
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Old 23rd March 2021, 12:18 PM   #475
mimi123 is offline mimi123  Spain
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Originally Posted by capslock View Post
I was surprised to see some of the ESS dacs turn up as mouser, including the data sheet and no NDA fuzz, they were just there to download. No adcs yet...
You can buy ADCs on the website Audiophile ADCs - Ismosys but is useless without the PDFs. I hope they were available soon.
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Old 23rd March 2021, 03:14 PM   #476
InspectorGadget is offline InspectorGadget
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Originally Posted by Markw4 View Post
ES9038PRO eval board appears to power DVDD, VDD_L, VDD_R all from the same regulator.
they are all connected internally, so no reason to do otherwise. check the notes after the pin descriptions table

Last edited by InspectorGadget; 23rd March 2021 at 03:23 PM.
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Old 23rd March 2021, 03:47 PM   #477
Markw4 is offline Markw4  United States
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They all run at the same voltage, but DVDD is a core logic digital power input. VDD_L and VDD_R are described as left and right analog power for the dac stage. Not finding where it says they are all connected together internally?
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Old 23rd March 2021, 03:52 PM   #478
InspectorGadget is offline InspectorGadget
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Originally Posted by syn08 View Post
Can somebody tell from their own experience how much current is the ES9038PRO taking from:

+1.2V Analog (VDD_L, VDD_R)
+3.3V Analog Reference (AVCC_L, AVCC_R)
+1.2V Digital Core (DVDD)
+3.3V Digital I/O (AVDD)
+3.3V Oscillator (VCCA)

I am confused by the numbers in the data sheet (attached).

- Are these per channel (L/R) or the sum of currents on both channels?
- Why are VDD_L, VDD_R and DVDD collapsed under the same value, are they assuming one will use the 1.2V supply to feed both the Analog and Digital Core sections.

I read that the current value scale up (as expected) with the clock frequency, @100MHz and 768KHz is almost double the values @40MHz and 48KHz, anybody has any current consumption measurements @100MHz?
they are total. I havent gotten as far along with the design as you, so i'm a ways off, although i'm about to order the chips at least and i'm working on my 9038q2m warm up. they have usually specified as total in their DS, although it's worded ambiguously.

as I mentioned. AVDD_L, AVDD_R and DVDD are all connected internally. I discovered that note, quite happily after doing a layout with separate regs for the AVDD, even 3 for those 3 pins, but it mentions they are all connected internally. That answers those pins. its specced for the 3 together.

regarding AVCC_L/R, if you take AVCC @ 3v3 * 0.924 = 3.0492 VPP, divided by the mono output impedance of 25Ω = 0.121968 * 1000 = 121.968mA output current, which is your 130 minus some margin, so it must be total for the dac.

Last edited by InspectorGadget; 23rd March 2021 at 04:03 PM.
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Old 23rd March 2021, 03:54 PM   #479
InspectorGadget is offline InspectorGadget
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Quote:
Originally Posted by Markw4 View Post
They all run at the same voltage, but DVDD is a core logic digital power input. VDD_L and VDD_R are described as left and right analog power for the dac stage. Not finding where it says they are all connected together internally?
yes, its not well worded at all, if you dont catch the notes section near the bottom of page 5, you would think they are separate.
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Old 23rd March 2021, 04:00 PM   #480
InspectorGadget is offline InspectorGadget
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I tried to copy the text, but it wont let me. I presume you have the DS, so you can just look.
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