Does an HDMI accessory device (i.e. switch box, cable booster) need a dedicated power supply to work?
The answer is usually No. The HDMI specification requires all source devices to provide at least 55mA on the 5V line of the HDMI connector. While 55mA is not enough current to operate most HDMI access devices (typically need about 100-150mA), most source devices on the market today provide significantly more current on the 5V line than the HDMI specification requires. As a result, the vast majority of accessory devices can operate without an external power source when interfaced with a source device that provides over 100-150mA.
Related Questions
- If an HDMI accessory device (i.e. switch box, cable booster) does not have a dedicated power supply, is it still compliant and will it work?
- Does an HDMI accessory device (i.e. switch box, cable booster) need a dedicated power supply to work?
- What happens to my DVR recordings if my digital cable box temporarily loses power?
