Patent attributes
A DLL includes a delay line with two phase outputs, a gater coupled with the delay line phase outputs, a PFD coupled with gater outputs, a PD coupled with PFD outputs, a retimer coupled with PD outputs, and a loop filter with inputs coupled with the retimer and a speed control output coupled with the delay line. The gater passes signals on its two inputs to its two outputs, apart from a first pulse on its first input. The PD determines if the second gated signal leads or lags the first gated signal. The retimer retimes PD output signals to be aligned with a delay line input signal. The loop filter uses the retimed PD output signals to determine if the delay line should delay more or delay less, and outputs a speed control signal to control the delay line speed.