Abstract: A microelectronic device includes a buried trench capacitor below an electronic component of the microelectronic device. In one embodiment, the buried trench capacitor may be formed between a silicon oxide capped p-type buried trench capacitor polysilicon region and a buried trench capacitor deep n-type region separated by buried trench capacitor liner dielectric. In a second embodiment, the buried trench capacitor may be formed by a buried trench capacitor polysilicon region and a p-type silicon epitaxial region separated by a buried trench capacitor liner dielectric. One terminal of the deep trench capacitor is made through the substrate via a deep trench substrate contact. The second terminal of the deep trench capacitor is made via a well contact that connects to the capacitor through a deep well region in one embodiment and through a polysilicon layer in a second embodiment.

Abstract: A minimum frequency synchronization discriminator for use in providing a clock signal for a switch mode power supply automatically detects when the frequency of a sync signal is above a minimum frequency and causes the sync signal to serve as the clock signal for the controller. If the frequency of the sync signal is below the minimum frequency, the minimum synchronization frequency discriminator causes the output signal of the internal oscillator to serve as the clock signal.