Patent ID: 8797203

Claim:
A low-power high-resolution time-to-digital converter comprising: a coarse delay cell configured to delay a reference clock by a coarse delay time and output the reference clock; a rising-edge retimer configured to output a rising-edge retimed clock synchronized with the rising-edge of a DCO (Digitally Controlled Oscillator) clock in response to the reference clock; a falling-edge retimer configured to output a falling-edge retimed clock synchronized with the falling-edge of the DCO clock in response to the reference clock; a first sampler configured to latch output of the coarse delay cell in response to the rising-edge retimed clock and the falling-edge retimed clock; and a pseudo-thermometer code edge detector configured to detect a rising-edge fractional phase error between the reference clock and the rising-edge retimed clock as a coarse phase error from a signal output by the first sampler, and detect a falling-edge fractional phase error between the reference clock and the falling-edge retimed clock.