摘要:
A cascoded cmos differential delay element is described. The delay element provides a controlled delay useful in forming voltage controlled oscillators or other circuits. The delay element provides high gain enabling it to be useful in multistage delay element circuits. The circuit described includes cascoded complementary differential amplifiers and replicated bias clamps.
摘要:
A serial data to parallel data converter is disclosed which has the advantage of accurately converting high frequency serial data to parallel data while using clock signals operating at a relatively low frequency. A low bit error rate is achieved by avoiding the use of multiple high speed clock lines typically found in other converters. The simplified circuit design also has the advantage of requiring minimal semiconductor layout area and reduced power requirements. One embodiment includes a buffer, a first data delay line, coupled to receive serial data from the buffer, and a phase lock loop (PLL), coupled to receive serial data from the buffer. A second data delay line is configured as a voltage controlled oscillator (VCO) within the PLL. The PLL locks onto the incoming serial data signal and provides a control signal back to the first data delay line to ensure it is storing serial data bits as they arrive. After n-bits of data have been transmitted the first data delay line contains a n-bit wide parallel word.
摘要:
A circuit constructed in accordance with this invention includes means for asynchronously forcing a flip-flop (70) or a register to a programmable logical state in response to an initialization input signal (I). In one embodiment, a D-type flip-flop (70) is provided having data input terminal (71), a clock input terminal (77), a data output terminal (103), an initialization input terminal (41), and a programming input terminal (11). When an initialization input signal I is received, a predefined output signal is immediately placed on the data output terminal (103). The predefined output signal is defined by the status of a fuse (13), which is opened, if desired, via the programming input terminal (11). When an initialization input signal is not received, the flip-flop (70) operates as a normal D-type flip-flop.
摘要:
A unique programming circuit, suitable for use with programmable read-only memories (PROM), or other circuits utilizing programmable fuses, is provided which overcomes several distinct disadvantages of prior art programming circuits. The programming circuit of this invention includes a Darlington pair of programming transistors which allows only a single programming transistor to be made large in order to carry the large programming current, and only a single high current drive signal need be applied to the single programming transistor, thereby minimizing power consumption and integrated circuit die area.
摘要:
The clock signal is the dominant source of electromagnetic interference (EMI) for many digital electronic devices. EMI generated by these electronic devices must be suppressed to avoid interference with other electronic devices and to satisfy FCC regulations. The present invention seeks to reduce EMI emissions by phase-modulating the clock signal using tunable delay lines. Phase modulation causes a spreading of the energy spectrum of the clock signal thereby reducing EMI emissions. In addition, the present invention is capable of generating a wide energy spectrum in a short time interval. Furthermore, the present invention can be similarly applied to other signals which exhibit a periodic or timing nature due to a correlation with the clock signal.
摘要:
One embodiment of the present invention provides a system for detecting light which is incident to a first semiconductor die. During operation, the system receives light at a photo-detector on the first semiconductor die, wherein associated circuitry converts the received light into a current. In doing so, the associated circuitry biases a gate voltage of an integrating transistor to be close to a threshold voltage of the integrating transistor, and applies the current from the photo-detector to the gate of the integrating transistor so that the current causes a charge to collect at the gate of the integrating transistor. This charge builds up and causes the integrating transistor to switch, thereby indicating that light has been received by the photo-detector.
摘要:
The present invention relates to an integrated circuit device and method of adjusting capacitance of a node of an integrated circuit In one embodiment, the device comprises a first digital input, a first parasitic capacitance block, a first output, a second digital input, a second parasitic capacitance block and a second output. The first parasitic capacitance block includes an inverter, a variable capacitance element, and a wire capacitance element. The first parasitic capacitance block has a capacitance that is a function of the first digital input. The first output is responsive to the first parasitic capacitance block, and the second output is responsive to the second parasitic capacitance block. In a particular embodiment, the method includes selecting a logic state of a digital input; applying the digital input to a parasitic capacitance block having an output, the output having a first capacitance when the digital input is in first logic state and a second capacitance when the digital input is in a second logic state; and adjusting a capacitance with respect to a second circuit node within the integrated circuit by applying the output to the second circuit node.
摘要:
One embodiment of the present invention provides a system for capacitively probing electrical signals within an integrated circuit. This system operates by placing a probe conductor in close proximity to, but not touching, a target conductor within the integrated circuit. In this position, the probe conductor and the target conductor form a capacitor that stores a charge between the probe conductor and the target conductor. Next, the system detects a change in a probe voltage on the probe conductor caused by a change in a target voltage on the target conductor, and then determines a logic value for the target conductor based on the change in the probe voltage. In one embodiment of the present invention, determining the logic value for the target conductor involves, determining a first value if the probe voltage decreases, and determining a second value if the probe voltage increases.
摘要:
An improved signal buffer configuration has been developed for transmitting communication signals across line traces between ICs on a printed circuit board, printed wiring board, multi-chip module, integrated circuit carrier or package, or other interconnect substrate. For example, in some realizations, multiple ICs having mismatched input and output impedances are mounted on an printed circuit board and communicate with each other via line traces. A signal buffer IC is placed in-line with the connecting line trace. The buffer is sized to fit within the pitch spacing of the line trace and contains an input impedance control circuit and an output impedance control circuit. These impedance control circuits are adapted to receive a control signal to set the input and output impedances of the buffer to correspond to the impedances of the connecting line traces. In this manner, the impedances between the ICs connected by this line trace are effectively matched and transmission line errors between them are reduced.
摘要:
A high speed self-terminated output driver includes an array of resistive drivers that are pulse-activated in succession to process a corresponding succession of data bits. The output driver thus synthesizes an output waveform which behaves similar to a single resistive drive element responding to the non-bandlimited input signal. In various embodiment, the output driver provides for digitally programmable output impedance and pre-distortion levels.