Power Integrations increases efficiency of display power supplies

2 mins read

Power Integrations, a specialist supplier of high-voltage integrated circuits for energy-efficient power conversion, has launched the InnoMux chipset for display power supplies.

According to the company, the chipset’s single-stage power architecture is unique and reduces losses in display applications by increasing overall efficiency in constant-voltage and constant-current LED backlight driver stages by 50% compared to conventional solutions, achieving up to 91% efficiency.

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

The chipset consists of an InnoMux controller IC that's been partnered with an InnoSwitch3-MX isolated switcher IC. The switcher IC 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 is able to independently measure 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 has been increased by 10%, 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.

The 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%.

Commenting Edward Ong, product marketing manager at Power Integrations said: “Developers can now 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 40 W power supply monitor power supply with one constant-voltage output and four constant-current outputs. DER-635 is a 45 W supply that supports TV applications, providing 2 CV and 1 CC output.