Abstract: A bias circuit produces a common mode bias voltage that relies upon active, auto tracking feedback responsive to the reference voltage, such as analog ground, and to the common mode bias voltage to generate a common mode voltage for a differential amplifier. The bias circuit supports high-speed operation, and is stable with variations in temperature, manufacturing processes, and with shifts in the supply voltages. In one embodiment, the bias circuit comprises an operational amplifier and a feedback amplifier that has a common mode bias terminal coupled to the output of the operational amplifier and arranged in a feedback loop with the operational amplifier. The output of the operational amplifier is used as a common mode bias voltage for a differential amplifier.

Abstract: A programmable and input voltage independent reference voltage generator. Size of reference voltage can be adjusted by controlling size of current using current mirrors and MOS switches. No decoding circuit is necessary. By adjusting the resistance value, current mirror and dimensional ratio of MOS, a chip area smaller than a decoding circuit can be used to accommodate the reference voltage generator. The reference voltage generator is able to provide an adjustable and stable reference voltage to different types of electronic modules. By providing a highly flexible reference voltage, performance of any circuits using the generator is boosted.

Abstract: An adjustable illuminating/retrieving apparatus comprising a flexible structure having a first end portion and a second end portion connected with a first end portion of an extension tube which includes a second end portion with a magnet fixedly mounted therein. A supporting base extends outward from the first end portion of the extension tube and is pivotally connected with a pivot base. A receiving tube includes a first end portion mounted on the pivot base and a second end portion formed with a first annular flange extending outward. A lighting unit is received in the receiving tube and partially extends outward of the second end portion of the receiving tube. A sliding sleeve is slidably mounted on the receiving tube and includes a first end portion formed with a second annular flange extending inward.