Patent · US Expired

Differental current source for generating DRAM refresh signal

US7180805B2 · kind B2 · utility

2Cited by

12References

14Claims

0Family size

Assignee

Infineon Technologies AG · DE

Inventors

Joachim Schnabel · Hersbruck, DE
Andre Schaefer · Hersbruck, DE

Key dates

Filing date	Mar 11, 2003
Grant date	Feb 20, 2007
Priority date	—
Expiry date	Jan 10, 2024

Classification

Technology area (CPC H)Electricity
CPC primaryH03K3/0231
WIPO fieldComputer technology
WIPO sectorElectrical engineering

Abstract

A circuit for generating a refresh signal for a memory cell of a semiconductor memory includes a capacitor and a differential current source for providing a charging current to the capacitor. The differential current source includes a temperature-dependent and a temperature-independent current source connected such that the charging current is proportional to a difference between a temperature-dependent current and a temperature-independent current. A comparator a voltage at a capacitor terminal and a reference voltage. The comparator generates a refresh signal when capacitor voltage exceeds the reference voltage.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.