摘要:
A hybrid-resolution panoramic VR generator places High-Resolution (HR) patches from a ring of HR cameras onto a 360-degree Low-Resolution (LR) image from a LR camera pointing upward from the ring into a panoramic mirror that captures the combined field of view of all the multiple HR cameras, but at a lower resolution. Ghosting artifacts caused by parallax errors between adjacent HR cameras are eliminated because object placement is determined by the 360-degree LR image. Each HR image is homographicly projected into 3 projections by grouping objects of different depths to obtain homographic matrixes. The 360-degree LR image is upscaled to HR and a query patch is searched in search windows in the three projections for up to two adjacent HR images. Best-matching patches are weighted by similarity with the query patch and blended to generate a reconstructed patch placed at the query patch location in a reconstructed HR panorama image.
摘要:
A sine wave generator for a Direct Digital Synthesizer (DDS) converts a digital phase input into a digital sine wave output. Sine values and slopes are stored in read-only memory (ROM) for coarse upper phase bits in a first quadrant. A quadrant folder and phase splitter reflects and inverts values from the first quadrant to generate amplitudes for all four quadrants. Each sine value and slope is stored for a range of lower phase bits. A Delta bit separates upper and lower phase bits. Delta conditionally inverts the lower phase bits, the sine value, and the final polarity. A reduced AND logic array multiplies the slope by the conditionally inverted lower phase bits. A reconstructed ADD logic array then adds the conditionally inverted sine value. The conditionally inverted polarity is added to generate the final sine value. Sine generation logic is streamlined with conditional inversion based on the Delta bit.
摘要:
A transistor-based full-wave bridge rectifier is suitable for low A.C. input voltages such as received by a Radio-Frequency Identification (RFID) device. Voltage drops due to bridge diodes are avoided. Four p-channel transistors are arranged in a bridge across the A.C. inputs to produce an internal power voltage. A comparator receives the A.C. input and controls timing of voltage boost drivers that alternately drive gates of the four p-channel transistors with voltages boosted higher than the peak A.C. voltage. Four diode-connected transistors are connected in parallel with the four p-channel bridge transistors to conduct during initial start-up before the comparator and boost drivers operate. Substrates are connected to the power voltage on the power-voltage half of the bridge and to the A.C. inputs on the ground half of the bridge to fully shut off transistors, preventing reverse current flow. The transistor bridge can be integrated onto system chips.
摘要:
An on-chip temperature sensor circuit can be implemented in a standard complementary metal-oxide-semiconductor (CMOS) process using PNP transistors. A pair of transistors have collector currents that are sensitive to voltage, both directly and due to saturation currents. A scaling resistor connects to the emitter of one transistor and its voltage compared to the other transistor's emitter voltage by an error amplifier that generates a bias voltage to current sources that are proportional to absolute temperature since the saturation current sensitivity is subtracted out. The current is mirrored to sink current through a multiplier resistor from an output. An amplifier connected across the multiplier resistor compares a reference voltage to set the DC bias independent of temperature sensitivity. The temperature sensitivity is proportional to the ratio of the multiplier resistor and the scaling resistor, and is multiplied by a mirroring factor. A differential output may also be provided.
摘要:
An on-chip temperature sensor circuit can be implemented in a standard complementary metal-oxide-semiconductor (CMOS) process using PNP transistors. A pair of transistors have collector currents that are sensitive to voltage, both directly and due to saturation currents. A scaling resistor connects to the emitter of one transistor and its voltage compared to the other transistor's emitter voltage by an error amplifier that generates a bias voltage to current sources that are proportional to absolute temperature since the saturation current sensitivity is subtracted out. The current is mirrored to sink current through a multiplier resistor from an output. An amplifier connected across the multiplier resistor compares a reference voltage to set the DC bias independent of temperature sensitivity. The temperature sensitivity is proportional to the ratio of the multiplier resistor and the scaling resistor, and is multiplied by a mirroring factor. A differential output may also be provided.
摘要:
An analog-to-digital converter (ADC) has a chopper-stabilized sigma-delta modulator (SDM). The SDM uses switched-capacitor integrators to sample, hold, and integrate an analog input in response to non-overlapping multi-phase clocks. Chopper multipliers are inserted on the inputs and outputs of an op amp in a first stage integrator. The chopper multipliers swap or pass through differential inputs in response to non-overlapping chopper clocks. A master clock operating at a frequency of the multi-phase clocks is divided down to trigger generation of the chopper clocks. Delay lines ensure that the edges of the chopper clocks occur before the edges of the multi-phase clocks. The chopper multipliers have already switched and are thus stable when multi-phase clocks change so charge injection at switches controlled by the multi-phase clocks is not immediately modulated by chopper multipliers. This clock timing increases the time available to respond to charge injection at switches improving linearity.
摘要:
A Digital Phase-Locked Loop (DPLL) has a digitally-controlled oscillator (DCO) that generates an output clock frequency determined by a digital input with most-significant-bits (MSB's) and a least-significant-bit (LSB). The LSB is generated by a Pulse-Width-Modulation (PWM) controller clocked by a control clock that is the output clock divided by C. A reference clock is compared to a feedback clock that is the output clock divided by M. The PWM controller generates M/C LSB's for each reference clock period and loads them in parallel to a parallel-to-serial shift register that serially delivers the LSBs. The pulse width is determined by a fine digital loop filter that filters phase comparison results using a fine time resolution. A coarse digital loop filter generates the MSB's from phase comparison results using a coarse time resolution. LSB waveforms are dithered by randomly selecting high-going or low-going pulses and randomly adjusting pulse widths.
摘要翻译:数字锁相环(DPLL)具有数字控制振荡器(DCO),用于产生由具有最高有效位(MSB)和最低有效位(LSB)的数字输入确定的输出时钟频率。 LSB由由控制时钟控制的脉冲宽度调制(PWM)控制器产生,控制时钟是输出时钟除以C。将参考时钟与输出时钟除以M的反馈时钟进行比较。PWM控制器 为每个参考时钟周期生成M / C LSB,并将它们并行并行串行传输LSB的并行到串行移位寄存器。 脉冲宽度由精细的数字环路滤波器确定,可以使用精细的时间分辨率对相位比较结果进行滤波。 粗略的数字环路滤波器使用粗略的时间分辨率从相位比较结果生成MSB。 通过随机选择高电平或低电平脉冲和随机调整脉冲宽度,对LSB波形进行抖动。
摘要:
An Analog-to-Digital Converter (ADC) has a Successive-Approximation-Register (SAR) driving a digital-to-analog converter (DAC) that generates an analog voltage compared to an input voltage by a series of stages. The last stage feeds a compare signal to the SAR. Each stage has a dual-input differential amplifier that operates as a unity gain op amp during an auto-zeroing phase and as a high-speed low-gain amplifier during an amplifying phase. The dual-input differential amplifier has two pairs of differential inputs. A secondary pair has an offset-storing capacitor across it, and connects to the output pair through feedback switches during auto-zeroing. A primary pair connects to stage inputs through input switches during the amplifying phase. Since two pairs of differential inputs are provided to the dual-input differential amplifier, the offset capacitor is completely isolated from the input pair. The current sink in the dual-input differential amplifier is adjusted higher during the amplifying period.
摘要:
A compact camera modules has first, second, and third lens groups that move along an optical axis. A stepping motor is centered on the optical axis rather than offset from the optical axis. The motor has two coils that are fixed in place and a shared rotating magnet. The magnet is attached to a rotating guide that has slots to move the first and second lens groups as it rotates. The two coils are alternately energized to rotate the magnet, the rotating guide, and to move the first and second lens groups for zoom. The magnet has alternating thicker and thinner segments of opposite polarity. The thicker segments exert a greater force on an autofocus coil that is energized to move the third lens for the autofocus function. The same shared rotating magnet is used for both zoom and autofocus functions. A more compact design is possible using a shared magnet.
摘要:
A Programmable-Gain Amplifier (PGA) has a digital value that programmably adjusts the gain of the analog amplifier. A variable capacitor has several switched sub-capacitors that are enabled by the digital value. Enabled sub-capacitors are switched between a sampled input and a virtual ground on one terminal, and connect to a summing node on the other terminal. The summing node connects to the inverting input of an op amp either through a switch or through a double-sampling capacitor that stores an offset. A feedback capacitor is in parallel with a sampling capacitor during a second clock phase when direct-charge transfer occurs, reducing power consumption of the amplifier. The feedback capacitor samples the sampled input during the first clock phase. The PGA gain is proportional to the sum of capacitances of enabled sub-capacitors. The gain can be adjusted for sensor inputs to an Analog Front-End (AFE), such as for an electro-cardiogram (ECG).