A/V Design and Integration With Bus Powered Solutions

Transcription

1 A/V Design and Integration With Bus Powered Solutions A/V Application And Integration Using USB, DVI-D, HDMI, DisplayPort And Thunderbolt Powered Systems Your Presenter Is: Jose Mozota, CTS National Sales Manager Low Voltage Division Middle Atlantic Products Canada

2 What Is Bus Power? Working With USB Solutions Working With DisplayPort Solutions Common Connectivity Considerations Working With HDMI/DVI Solutions Conclusions Our Agenda

3 What Is A Bus Powered Solution? The term bus describes an electrical connection between a host and a set of devices attached to and dependent upon the host Attached devices are called nodes Serial buses send information one bit after another over a single pathway Parallel buses communicate over discrete connections, typically equal to word length When the signal bus also provides operating power for the node, it is considered a power bus

4 What Kind Of Power? Alternating Current (AC) The flow of charge periodically reverses direction Typically a sine wave Direct Current (DC) Flow of charge is unidirectional Referenced to a constant, zerofrequency plane DC voltages can vary over time

5 How Much Power Are We Talking About? Modern laptops use Lithium Ion batteries Batteries contain a number of cells in a series/parallel 'string Charging voltage is typically more than the terminal voltage Lithium Ion cells have 3 volt terminal voltage (4.2V charging) 3 cells in series (3S) = 9v 4 cells in series (4S) = 12v 6 cells in 2 parallel strings of 3 (2P3S) = 9v 8 cells in 2 parallel strings of 4 (2P4S) = 12v Connectivity chip sets use 3.3 to 5 volts

6 What Does G. S. Ohm Say About This? Ohm s Law is an empirical law that states current is approximately proportional to electric field 5 meters of 32AWG copper wire will add 5.4Ω in series with the load 200mA = volt A loss of 21.6% 300 ma = volt A loss of 54% 50mA = -.27 volt A loss of 5.4% Voltage tolerances in devices are typically specified at +/- 5%

7 Why Does This Matter? Hot plug detect is a signal that informs the source that a sink (display or load) is connected Source provides +5V to the sink, which the sink sends back to the source as an assertion voltage Repeaters and switchers may be required to pass a hot plug pulse to an upstream device

8 What Can Go Wrong? Detecting proper voltages is the core of the hardware handshake Hot Plug connection detect Plug and Play EDID exchange Content protection HDCP key authentication and exchange When proper voltages are not present in a connected system Complete loss of picture is typically hot plug related Distorted video may be an EDID related issue Flashing images are often indicative of HDCP problems

9 Global Industry Analysts, Inc. predicts sales of USB 3.0 enabled devices will top 3 billion in 2018 with a peak CAGR approaching 80% in some markets! BUS POWER AND USB

10 USB Is The Universal Battery Existing USB technology specifies a 5V (+/-5%) power supply In USB, power is delivered in quanta of unit loads Single unit load in USB 1.1 & 2.0 is defined as 100mA High-power devices draw up to the maximum number of unit loads permitted (5 unit loads) USB 1.1, 2.0 and 3.1(gen 1) all treat power similarly Minimum operating voltage of 4.4 V in USB 2.0, and 4 V in USB 3.0

11 USB Battery Charging Specification (2007) Standard USB com ports require the device to negotiate power demands with the host after the first unit load is allocated Charging downstream port (CDP) can supply currents between 500 ma and 1.5 A without the digital negotiation May supply up to 500 ma at 5 V Up to the rated current at 3.6 V or more Drops output voltage if the device attempts to draw more than the rated current USB specs limit inrush current Standard USB 2.0 A-connectors are rated at 1.5 A

12 USB Power Standards Chart

13 Typical USB Power Exchange 1. Hub is assigned 100mA to start Five meters maximum 2. When connected to the hub, the function is assigned 100 ma 4. If the hub is bus powered it will negotiate with the source for additional unit loads Sleeping inactive devices are pulling power to facilitate instant on Bus powered hubs are consuming at 1 unit load for operational power Five meters maximum 3. If the function needs more than 100mA (1 unit load), the function will negotiate with the hub for additional unit loads

14 Analyze A Simple Classroom System If passive, -100mA Bus Powered -100mA How much power does this device require? Hidden Passive Hub -100mA How confident are we that this simple classroom system will work? What should we consider in this design? What other devices are connected to the IWB and how much power to they require?

15 A More Sophisticated Installation All functions connected to hub can access full power Powered Hub Powered Extender Full power is delivered to interactive frame for confident performance Each port can supply up to 900mA for charging and operation Interactive frames universally require high power, 500mA We ve designed this system to work!

16 There are a lot of things wrong with HDMI. For one, the technology keeps pushing the limits of what a standard non-active cable can handle - this is especially true when HDMI is used over long distances. Audioholics Magazine BUS POWER AND HDMI

17 Let s Dissect HMDI HP DDC DDC CEC B B R R +5V DDC HEAC S S G G

18 HDMI Power HDMI specification requires all source devices to provide at least 55mA on the 5V line Located on Pin 18, must be 4.7 to 5.3V 55mA is not enough current to operate most HDMI accessory devices, but in common practice most source devices provide more current on the 5V line than the HDMI specification requires Design considerations should be based on specification, not common practice HDMI power is intended for hot plug detection HDMI source provides +5V to the sink which the sink sends back as the hot plug assertion voltage on pin 19 HDMI power is used for reading EDID

19 Active HDMI Over Copper Directional, active cables that incorporate a chip set to pre-equalize the signal so that it maintains eye pattern fidelity Example used - Redmere MEA1689 Chipset Bus powered solution no external power supply option. Powered by HDMI bus. Circuit is limited to 3.4Gbps per channel (1080p) Chipset is embedded at the sink connection Stacking an active, embedded chip with an external bus-powered device (a switch, for example) may cause system instability If embedded chip is at the sink, voltage drop over the length of the cable may still be an issue Picture Courtesy of

20 HDMI Embedded Media Converters An embedded media converter is a chip that fundamentally changes the signal to leverage a completely different optical or electrical connection topology Some examples include RapidRun Optical, AOC, Celerity Optical Gateway Often these systems will leverage a USB power connection Transmitter function may be powered by the HDMI or DisplayPort bus Stacking should be avoided If copper is not co-run with the optical channel the power must be sourced at both the source and sink components Example shown, RapidRun Optical

21 How Can I Fix An HDMI Power Issue? HDMI has a long history of challenges in installation Because of this there is a demand for solutions to common problems Many installation failures associated with sagging power and/or under-current situations can be addressed with a voltage inserter However, multiple breaks in HDMI connection can induce distortion in the eye pattern. It s important to analyze connection segment lengths.

22 I hope more display manufacturers adopt this standard, because DisplayPort rocks. - Michael Brown Senior Editor, PCWorld BUS POWER AND DISPLAYPORT

23 DisplayPort Is The VGA Of The 21 st Century!

24 DisplayPort Power DisplayPort is designed to replace older standards like DVI and VGA Hot plug detect on pin 18, power on pin 19 (return) and 20 for DisplayID/DDC Runs at ma for maximum utility in mobile devices Thunderbolt combines PCI Express and DisplayPort into one protocol Uses the same connector as Mini DisplayPort (MDP) Designed so all peripherals can driven off of the same bus Up to ma (9.9 watts)

25 Let s Dissect DisplayPort Power Return 500mA Aux Lane 0 Hot Plug Lane 3 Lane 2 Config Lane 1

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27 Thunderbolt & Mini-DP Hot Plug Detect DisplayPort Power

28 Symmetrical, Compact, Powerful This next generation of USB technology opens the door for the invention of an entirely new, super thin class of devices that consumers haven t even seen yet The USB Type C Connector Designed for 10,000 plug/unplug cycles Robust enough for laptops and tablets; slim enough for mobile phones

29 Potential DisplayPort Issues DisplayPort exhibits similar potential for Hot Plug Detect or DDC/EDID communication failure as other connection standards With the added complexity that the sink must pull voltage up to 5V from 3.3V DisplayPort to VGA adapters include a D/A chip set Chip set requires power to operate and this may affect battery life and/or link length

30 Here s Your Take Away Education is what survives when what has been learned has been forgotten. B. F. Skinner

31 USB operates at 5 volts and 500mA per port USB, as implemented today, delivers power in quanta of unit loads where each unit load = 100mA The power bus in DVI-D, HDMI, DisplayPort and Thunderbolt connections is designed for Hot Plug Detect and to read EDID information DVI-D and HDMI operate on a 5 volt bus and are designed to deliver at least 55mA of current DisplayPort operates on a 3.3 volt bus and is designed to deliver 500mA DisplayPort and HDMI/DVI-D bus supplies were not envisioned as power supplies for peripherals

32 Beware, Bus Powered Solutions Are Everywhere! When we remember we are all mad, the mysteries disappear and life stands explained.. Mark Twain

33 Bus Powered Solutions In A/V Applications Questions?