Browse Prior Art Database

Phase Shift Compensation in a Bucket Brigade Shift Register

IP.com Disclosure Number: IPCOM000087143D
Original Publication Date: 1976-Dec-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 73K

Publishing Venue

IBM

Related People

Dubil, JF: AUTHOR

Abstract

A method is disclosed for laying out the tap positions of a bucket-brigade circuit so as to compensate for signal phase shift or delay due to charge transfer inefficiency.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Phase Shift Compensation in a Bucket Brigade Shift Register

A method is disclosed for laying out the tap positions of a bucket-brigade circuit so as to compensate for signal phase shift or delay due to charge transfer inefficiency.

It has been found that by correlating the voltage signal phase shift as a function of the signal charge transfer inefficiency for a multiple tap bucket-brigade device and then moving the designed tap positions closer to the beginning of the bucket-brigade device by an amount proportional to the total number of cells in the device, the magnitude of which is determined from the correlation step, the signal phase shift due to charge transfer inefficiency in the device is compensated.

Charge transfer inefficiency is a term used to identify the inability of a bucket- brigade device to transfer 100% of the signal information from one circuit node to the next in a bucket-brigade shift register. This charge transfer inefficiency tends to distort the input voltage signal in a cumulative manner as it passes through the bucket-brigade shift register.

By deriving a mathematical model representing the voltage signal in a bucket-brigade shift register as a function of an input signal to the register and the charge transfer inefficiency, the effects of adjusting the tap position on phase shift and signal delay can be observed.

Fig. 1 illustrates signal waveform as a function of time as it travels from a node, and Fig. 2 illustrates a signal waveform as a function of time as the waveform travels to a node. The model for the voltage signal in the bucket- brigade shift register is given below. The assumptions made are: (1) Delta Q(i) = Delta...