摘要:
To provide a time measuring apparatus which is compact and capable of highly accurate measurements, on a semiconductor chip, flip-flops constituting a delayed-signal holding circuit of a first channel and flip-flops constituting a delayed-signal holding circuit of a second channel are disposed alternatingly and in a single row in a circuit region of the delayed-signal holding circuits to latch delayed signals from a pulse-circulating circuit, and flip-flops for latching the same delay signals are mutually adjacent. Due to this, distances between the pulse-circulating circuit and the respective delayed-signal holding circuits become equal, and delay signals having no deviation in delay due to difference in wiring length are supplied to the respective channels, and so uniform measurement can be performed between the respective channels.
摘要:
A method of placing delay units of a pulse delay circuit on a programmable logic device having logic cells in each of cell strings has a step of arranging each delay unit in one logic cell of the device such that the delay units are placed in respective specific cell strings aligned in a row direction and a step of serially connecting the delay units with one another as a straight delay line such that the delay units placed in the specific cell strings in the connecting order are aligned in the row direction. In the device, an inter-string transmission delay time on a line between two logic cells of different cell strings differs from an intra-string transmission delay time on a line between two logic cells of one cell string.
摘要:
An A/D converter has a series of M delay units through which a pulse signal is transmitted while being delayed in each delay unit by a delay time depending on a level of an analog signal. A unit of the converter latches the pulse signal outputted from each delay unit at N sampling times to hold M×N latched data. Another unit of the converter receives the M×N pieces of latched data as a piece of combined data composed of the latched data arranged in an order corresponding to an arranging order of M×N sampling points in the pulse signal, converts the combined data into numeral data, corresponding to a position of the pulse signal in the delay units, at one time, and produces converted digital data corresponding to the level of the analog signal from the numeral data.
摘要:
A pulse signal circulates around a ring of delay elements with respective traversal signals being thereby successively outputted from the delay elements. The period of a reference signal is multiplied or divided by a real number to obtain control data specifying a required period of a clock signal as a value having an integer part and a fractional part. The control data are used to select the timings of specific traversal signal, and the clock signal is generated based these selected timings, with the timing selection being repetitively adjusted in accordance with the fractional part of the control data.
摘要:
An image sensor has plural array blocks B1 to B20 arranged in a two dimensional (2D) arrangement. Each array block has a sub array and a corresponding analogue to digital (A/D) converter for performing an A/D conversion of light signals (or detection signals) output from the sub array. The sub array has plural picture element cells arranged in a 2D arrangement. Each A/D converter has a pulse delay circuit having delay units of plural stages connected in series. Each delay unit delays an input pulse by a delay time corresponding to a level of the light signals received from the sub array. A pulse delay type A/D converter is used as the A/D converter, which outputs the number of the delay units as an A/D conversion data item through which the input pulse passes for a measurement time period.
摘要:
An inverter circuit configuring a delay unit is a so-called CMOS transistor including a PMOS transistor and an NMOS transistor, of which respective gates are interconnected and respective drains are interconnected. The source and a back gate of the NMOS transistor are connected to the ground. The source of the PMOS transistor is connected to a positive drive terminal and controlled by an analog input signal. The back gate of the PMOS transistor is connected to a control terminal and controlled by a control signal.
摘要:
For testing an A/D converter circuit including a pulse delay circuit constituted by a plurality of cascade-connected delay units, and an encoding circuit configured to count the number of the delay units through which the input pulse signal passes within a predetermined measuring time and to output a digital signal representing the counted number, the method includes the steps of setting the A/D converter circuit in a test mode where the measuring time is set at a short test-use sampling period, applying the input pulse signal to each of serial delay blocks each of which is constituted by a predetermined number of the delay units, and determining good and bad of the A/D converter circuit on the basis of digital signals outputted from the encoding circuit representing the numbers of the delay units through which the input pulse signal has passed within each of the serial delay blocks.
摘要:
In a TAD (Time Analog-to-Digital) type of A/D converter in which delay units of a pulse delay circuit successively transfer a pulse signal during each of successive measurement intervals, with each delay unit applying an amount of delay determined by an analog input signal voltage, it is ensured that each new measurement interval begins as soon as the pulse delay circuit has become restored to an initialized condition after the preceding measurement interval. Output values expressing the number of delay units traversed by the pulse signal during a measurement interval are used directly as digital values representing the analog input signal voltage level.
摘要:
A method for correcting A/D converted output data which corrects digital data obtained by A/D conversion of an analog signal, comprising forming an at least first order polynomial curve approximating an input/output characteristic curve of A/D conversion in a range of input of the analog signal, setting an ideal input/output characteristic line of A/D conversion, deriving a conversion equation for converting coordinates of a point on the approximation polynomial curve to a point of the ideal input/output characteristic line for the same analog signal value, and using this conversion equation to convert A/D converted digital data so as to correct non-linearity of the output data.
摘要:
An A/D converter for driving a plurality of delay units forming a pulse delay circuit by an analog input signal Vin and digitalizing the number of delay units through which a pulse signal passes in the pulse delay circuit at predetermined timings, provided with a plurality of pulse position digitalizing units used for A/D conversion and inputting delay pulses from the delay units of the pulse delay circuit to the pulse position digitalizing units through an inverter group comprised of inverters with different inversion levels (switching threshold level) by different input timings. The digital data obtained by the pulse position digitalizing units are added by an adder.