Frequency divider circuit with controllable frequency division ratio and method for frequency division in a frequency divider circuit

Abstract

A frequency divider circuit is disclosed with at least one push-pull divider with adjustable division ratio and a connected converter device. The circuit converts a clock signal delivered by a push-pull divider into a single-ended signal. A first and a second single-ended divider are connected to the output of the converter device, and a feedback path is provided, which is connected to the output of the push-pull divider and to the outputs of the first and of the at least one second single-ended divider, and which includes an evaluation circuit. This circuit has first and second inputs which are connected to the first and second single-ended dividers in such a way that a future state of the clock signal delivered by the single-ended divider in question can be supplied to the inputs of the evaluation circuit. The evaluation circuit evaluates states of the clock signals delivered by the first and second single-ended dividers, i.e., states which will not exist until after future switching functions have been performed. As a result, additional time is gained for converting the signal to be divided from a push-pull signal to a single-ended signal.