Voltage detector IC cuts TV’s standby power

Article By : Peter Clarke

A University of Bristol UB20M voltage detector IC activates a power gating switch in a TV's 12V supply, and cuts off the TV's standby power.

« Previously: Comparator circuit nulls standby power

Researchers at Electrical Energy Management Group of the University of Bristol have developed and demonstrated two variations of their low-voltage comparator circuit that could be used to nullify standby power. The research team has come up with the UB20M and the UB20L that are both implemented in 180nm HVCMOS by AMS.

The research team pointed out that modern TVs consume 0.5W or 6AA batteries per day in standby so that they can be "switched on" from a remote controller. In the past, they consumed as much as 10W or 15W. There is also the apocryphal argument that in its lifetime a microwave consumes more energy powering its display than heating food, because for more than 99% of the time it sits in standby.

Potential interfaces

The University of Bristol team has demonstrated a TV that uses the UB20M voltage detector IC to eliminate this standby power. The quiescent current of the detector of 5.4pA at 1V, allows the detector to be powered up from infrared photodiodes that are illuminated by an infrared TV remote controller. The UB20M detector activates a power gating switch in the TV's 12V supply, in order to cut off the TV's standby power.

The circuit could also have applications in more conventional consumer products such as televisions, microwaves and voice-activated interfaces.

The UB20M has a threshold of 0.6V and draws sub-10pA. The UB20L switches at 0.46V, but draws up to 100pA. "We are now actively seeking commercial partners to use the voltage detector chip in their product and would welcome companies to get in touch," said Stark.

First published on EE Times Europe.

« Previously: Comparator circuit nulls standby power

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