A collapsible, portable canopy is adapted for use with a co-sleeper, crib or play yard. The PLL circuit includes a Voltage Controlled Oscillator and a plurality of filter comparators receiving a differential filter VCO control voltage. The switching control signal applied to the power bridge is then regulated based on the acquired estimates. The first electrode has a light-transmitting property, and the layer containing the first organic compound and the layer containing the second organic compound are interposed between the second electrode and the light emitting layer.