HBT (Heterojunction Bipolar Transistor) device-based presettable D trigger

Abstract

The invention discloses an HBT (Heterojunction Bipolar Transistor) device-based presettable D trigger, which mainly solves the problems of low working speed, high phase noise and low working frequency existing in the prior art. The D trigger comprises a first latch (1), a second latch (2), a preset circuit (3) and a selection circuit (4), wherein a differential output of the second latch is connected with the preset circuit; the preset circuit is used for sampling and outputting a preset signal input by an external circuit; current signal input ends of the first latch, the second latch and the preset circuit are connected with the selection circuit; the selection circuit is used for selecting a working circuit; and all transistors in the unit circuit are heterojunction bipolar transistors. In the D trigger, a trigger function or preset function can be realized under the control of a selection signal; and the D trigger has the advantages of high working speed, low phase noise, high working frequency and the like and can be applied to a high-speed program frequency divider.

Description

technical field [0001] The invention belongs to the technical field of integrated circuit design and relates to a flip-flop, in particular to a presettable D flip-flop based on an HBT device, which can be used in a program frequency divider. technical background [0002] The program frequency divider is an important part of the phase-locked frequency synthesizer. Many important characteristics of the frequency synthesizer are related to the performance of the program frequency divider. For example, the working speed of the program frequency divider limits the output signal of the frequency synthesizer. At the highest frequency, its phase noise affects the in-band phase noise of the frequency synthesizer. Therefore, it is particularly important for a high-performance frequency synthesizer to increase the speed of the program frequency divider and reduce the phase noise of the program frequency divider. [0003] The fundamental difference between the program frequency divider...

AI Technical Summary

Problems solved by technology

[0006] 1) Slow working speed, not suitable for high-speed program frequency divider;

[0007] 2) The phase noise is high, which makes the phase noise of the whole program frequency divider high;

[0008] 3) The working frequency is low, so it is not suitable for the program frequency divider in the higher frequency band

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