Patent ID: 7593277
Filing Date: 2009-09-22
Classification: G11C

Abstract:
1. A method of sensing a current relative to a reference current, comprising: providing a sensing circuit for sensing the current, said sensing circuit sensing over a predetermined period to produce either first or second signal depending respectively on whether the sensed current is greater or less than the reference current; providing a reference sensing circuit having substantially similar characteristic and operating conditions as the sensing circuit; sensing the reference current with the reference sensing circuit; determining a sensing period corresponding to the reference current by timing a voltage on a node of the reference sensing circuit being discharged by the reference current from a first predetermined level to a second predetermined level, said voltage discharging to the second predetermined level causing the reference sensing circuit to produce a signal that changes from the first to the second signal; and sensing the current with the sensing circuit while using the determined sensing period to time the predetermined period.