High Tech Technology Limited

Ka Lok (Roy) Ng

Chik Wai (David) Ng

Wai Kit (Victor) So

Tin Ho (Andy) Wu

Kit Wing (Simon) Lee

Yuanzhe (Kevin) Xu

Sheung Wai (Orange) Fung

A re-configurable bank of DC-DC converters has many channels, each with a DC-DC converter and a controller that senses the channel's output voltage and current to adjust a duty cycle of switch signals to the DC-DC converter. A serial bus connects to all controllers and writes digital voltage and current control targets into each controller. The controller has Digital-to-Analog Converters (DACs) that convert the targets to analog voltages that are compared to sensed output voltage and current. The comparison results are compared to a sawtooth wave to generate pulses of the switch signals that have a duty cycle adjusted for the target comparisons. In combined mode, a primary channel's controller generates switch signals for secondary channels having outputs shorted to the primary channel. Secondary channels have a mux to select switch signals from the primary controller during combined mode, and from the secondary controller during separated mode.

Flexible array of DC-DC converters reconfigurable using a shared serial bus

A modulator spreads the spectrum of a generated clock to reduce Electro-Magnetic Interference (EMI). A capacitor is charged by a variable current to generate a ramp voltage that is compared to a reference to end a clock cycle and discharge the capacitor. An up-down counter drives a Digital-to-Analog Converter (DAC) that controls the variable charging current to provide triangle modulation. A smaller offset current is added or subtracted for cubic modulation when the up-down counter reaches its minimum count. A frequency divider that clocks the up-down counter also clocks a Linear-Feedback Shift-Register (LFSR) to that controls pseudo-random current sources that further modulate variable current and frequency. The LFSR is clocked with the up-down counter to modulate each frequency step, or only at the minimum count to randomly modulate at the minimum frequency. Binary-weighted bits from the up-down counter to the DAC are swapped to modulate the frequency step size.

Digital frequency dithering for switched-mode power supplies (SMPS) using triangular, asymmetric cubic, or random cubic spread spectrum oscillators

Growing community of inventors

Hong Kong, China

Ka Lok (Roy) Ng