Increased efficiency of display power supplies with new technology

Additionally, TV and monitor designers can realise over 50% reduction in component count, reducing manufacturing cost and providing an associated improvement in board reliability.

The new chipset consists of an InnoMux controller IC partnered with an InnoSwitch 3-MX isolated switcher IC. The InnoSwitch3-MX is the latest addition to Power Integrations’ flyback switcher IC families, combining the primary FET, the primary-side controller, a secondary-side controller for synchronous rectification, and FluxLink high-speed communications technology, which eliminates the need for an optocoupler.

The InnoSwitch3-MX receives control information from the InnoMux IC, which independently measures the load requirements of each output and directs the InnoSwitch3-MX switcher to deliver the right amount of power to each of the outputs to maintain accurate regulation of current or voltage; this eliminates the load and cross-regulation challenges seen with conventional multi-output power supplies, making post-regulators unnecessary.

Overall power conversion efficiency increases by ten percent, removing the need for heatsinks and eliminating hotspots while easing compliance with the upcoming ENERGY STAR 8.0 display specification and the new CEC power-consumption standard scheduled to take effect in July 2019. 

InnoMux technology supports both accurately regulated constant-current and constant-voltage outputs simultaneously, supplying one to four channels of constant-current and up to two constant-voltage outputs. This flexibility supports the logic, audio and LED requirements typically seen in TV and monitor displays.

The IC provides overload protection for each output. InnoMux technology also supports sophisticated dimming on the LED CC output, analog, PWM, interleaved and hybrid dimming are controlled via dedicated analog and PWM control pins, allowing accurate dimming down to 1.5%.

Comments Edward Ong, product marketing manager at Power Integrations: “Developers can leverage InnoMux’s power conversion efficiency in two ways: they can develop highly efficient monitors and TVs to meet manufacturer targets and regional regulatory mandates, or they can downgrade the efficacy, and therefore the cost, of their display panel by using less expensive LEDs and simpler, cheaper, diffusers while still meeting upcoming ENERGY STAR 8.0 rules.”

Two reference designs, DER-635 and DER-636, are available. DER-636 describes a 40W power supply monitor power supply with one constant-voltage output and four constant-current outputs. DER-635 is a 45W supply that supports TV applications, providing 2 CV and 1 CC output. Samples will be available in the second quarter of 2019.