Electronic Engineering Blog

ATEM Mini – Secrets and opportunites?

The ATEM Mini is an awesome HDMI Switcher from Blackmagic Desgn. With 4 HDMI Inputs, one HDMI Output, and one ‘WebCam’ USB output it offers great value for money. It is widely used by video bloggers and YouTubers for quickly changing camera angles and views, and is also a fantastic addittion to any livestream setup for places of worship, gigs and gamers. But what lies inside – does it hold any secrets? My teardown reveals some interesting facts. Read on…


The ‘Mini’ part of a family of small HDMI siwtchers. It’s two siblings are the ATEM Mini Pro and ATEM Mini Pro ISO, which add featues like livestream without a PC (Pro) and 5-Channel Recording to USB (ISO).

This is not a review – there are hundreds of them on the net already. This is a look under the hood at what makes this clever little device work. During a teardown what I found was both impressive and surprising. I think this baby has more to give.

HDMI Inputs
Lets start with the HDMI Inputs. There are 4 inputs whch, according to the technical specifications, support a wide range of resolutions and formats. They are all listed as HD capable, but not 4K. However they are not all equal – Input one goes to a TI TMDS171 HDMI Re-timer chip – which can support 4K and the other three inputs go to Analog Device’s ADV7610 chip.

HDMI 1 on ATEM Mini.

So why is Input 1 treated differently? I think the goal here was to allow input 1 to do a fast passthru to the output, because as we shall see later, the HDMI output hardware can also technically support 4K. However at the time of writing this feature is not mentioned anywhere in the documentation.

Inputs 2 through 4 used ADV7610

HDMI Output
The HDMI output comes from a TI TDP158 Chip – another chip which is technically capable of outputting 4K – so in theory, with the correct firmware you could imagine a scenario where input 1 supports 4K, and the output supports 4K, with inputs 2,3,4 being HD. You could even do a fast passthru from Input 1 to the Output without going via a frame buffer. That would be cool.

Output – 4K Compatible?

USB Output
The USB Output is on a Type-C connector – which might lead you to think it could handle USB-3 speeds and devices – but alas, (on the MINI at least), it is only used in USB-2 mode, with only the DP and DM usb signals present – and it’s hooked up to an On-Semi FUSB2805 chip – which is strictly USB 2.0 only.

USB 2 on a Type-C connector.

At least the tech specs are honest about this – they clearly state that the output is USB 2.

Now here’s an anomoly the Ethernet capabilities seem to be understated. The tech specs say the device supports 10/100 Mbps ethernet – but the controller IC for the Ethernet is a TI DP83867CR which is a gigabit ethernet PHY!

Audio Inputs
There’s not much to say about the two separate audio inputs on the 3.5mm jacks – they get fed into a bog standard PCM1865 4-Channel Audio Dac. They do allow a bias voltage to be applied – which might be useful for lapel mics.

Overall Control – The brains of the operation
Pulling all of this together, and sitting right at the heart of the operation is a XILINX ZYNQ-7015 SoC – it’s a very impressive FPGA with dualcore Arm Cortex 9 hard MCUs. The SoC is interfaced to 1 GBYTE (4 x 2 Gbit) DDR3 SDRAM, and a 256 Mbit SPI Flash. This is an impressibely powerful SoC

© Zilinx

So the MINI has what looks like a 4K capable input, 3 HD Inputs, and 4K capable output. It has a USB 2.0 Output in a USB-C dress, and a gigibit ethernet port – but not all these features are enabled or used to their full potential. Maybe as you go up the range from Mini to Pro to ISO the SoC Firmware gets more and more capable – I don’t know, I don’t have a Pro or ISO to compare with – or maybe, just maybe, there’s scope for future Firmware updates to tease a bit more out of this fantastic little device. One update I’d love to see is to enable a multi-view preview on the USB output allowing you to preview all 4 inputs before switching one to the HDMI output.

There’s one more thing…
Unde the hood Blackmagic Design have not tried to hide anything. None of the part numbers are removed, or obfuscated. They could easily buy these components with custom markings. Many of the testpoints on the PCB are clearly marked with their function. There’s also this curious header :

Curious UART header

… which carries UART TX and RX signals. I wonder what we’d see if we probed them….

Maybe, just maybe, there’s a cunning plan in play here. Just like certain oscilloscope manufacturers which supply a range of ‘scopes with different capabilities, all built from the same hardware, knowing that the casual users will buy the cheap one and then they leave the door open for users to ‘hack’ it up to full capability – and the manufacturers never close that door becauase they know it drives sales. Could BMD be taking a page from that book? Either way the ATEM Mini is a fantasically capable device – even more so once you install the control app which brings out features not available from the buttons – and is definitely a go-to product for me. Go get one!

I am not in any way affilliated to Blackmagic Design or any of it’s distributors. I do not earn any commissions or remuneration from this review. I was not paid by anyone to write this article.

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