Abstract:
A data compression system comprises an analog-to-digital converter for quantizing the analog signal at a first sampling frequency into a series of digital samples and a memory for storing the digital samples. A control circuit generates a sampling datum indicating a variable sampling frequency lower than the first sampling frequency as a function of the instantaneous frequency of the analog signal for selecting digital samples from the memory, reads the selected digital samples out of the memory means in response to the sampling datum, and forms the sampling datum and the selected digital samples into a data set. A series of data sets may be transmitted to a receiving end of the system or stored in a recording medium. The sampling datum is used to indicate the point at which the digital sample is converted to a corresponding analog value.
Abstract:
One embodiment of the present invention provides a time-to-digital (TDC) converter, comprising: a means for receiving a start signal and a stop signal; a means for generating n number of first delayed start signals (where n is an integer of 2 or more) in 1 time unit increments of delayed start signals; a means for generating a first delayed start signal and an output byte according to the logic level of the stop signal; a coarse TDC which generates a second delayed start signal, which is 1 delayed start signal selected from among the first delayed start signals, that has been shortened to less than the 1 time unit increment; a means for receiving the second delayed start signal generated by the coarse TDC and the stop signal; and a fine TDC for measuring the time difference between the second delayed start signal and the stop signal as a second time unit. According to the present invention, linearity and reliability can be improved by extending the measurement range of a fine time-to-digital converter and ensuring fast operation speed and high accuracy.
Abstract:
PURPOSE: A TDC(time to digital converter) and a converting method is provided to maintain linearity by expanding a measurement range of a fine time-to-digital converter. CONSTITUTION: A coarse TDC(1000) comprises a plurality of delay cells(1110-11n0) and a plurality of bit detectors(1210-12n0). The plurality of delay cells receives an input signal, respectively. The plurality of delay cells delays the received input signal during predetermined time. The plurality of bit detectors receives a delayed start signal and stop signal, respectively. The plurality of bit detectors determines an output bit according to a logic level of the received delayed start signal and stop signal, respectively. An encoder(10) receives output bits from the bit detectors of the coarse TDC. The encoder outputs the coarse time between the stop signal and the start signal according to the value of the output bit. [Reference numerals] (10) Encoder; (1210) First bit detector; (1220) Second bit detector; (12n0) Third bit detector; (SP) (stop signal); (SS) (start signal)