Integrated Circuit with Analog or Multilevel Storage Cells and User-Selectable Sampling Frequency

• US 20060256626A1
• Filed: 07/27/2006
• Published: 11/16/2006
• Est. Priority Date: 06/30/1998
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Andreas M. Haeberli, Carl W. Werner, Cheng-Yuan Michael Wang, Hock C. So, Leon Sea Jiunn Wong, Sau C. Wong
• Inventors: Werner, Carl W., So, Hock C., Wong, Leon Sea Jiunn, Haeberli, Andreas M., Wang, Cheng-Yuan Michael, Wong, Sau C.
• Granted Patent: US 7,298,670 B2
• Time in Patent Office: Days
• US Class Current: 365/189.20
• CPC Class Codes: G11C 11/56 using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: G11C 11/5621 using charge storage in a floating gate
• CPC Class Codes: G11C 11/5628 Programming or writing circuits; Data input circuits
• CPC Class Codes: G11C 11/5642 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 16/12 Programming voltage switching circuits
• CPC Class Codes: G11C 16/30 Power supply circuits
• CPC Class Codes: G11C 16/32 Timing circuits
• CPC Class Codes: G11C 27/005 with non-volatile charge storage, e.g. on floating gate or MNOS
• CPC Class Codes: G11C 27/02 Sample-and-hold arrangements G11C27/04 takes precedence
• CPC Class Codes: G11C 27/026 associated with an amplifier G11C27/028 takes precedence
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence
• CPC Class Codes: G11C 7/16 Storage of analogue signals in digital stores using an arrangement comprising analogue/digital [A/D] converters, digital memories and digital/analogue [D/A] converters

Abstract

Techniques are used to store information in a medium such as the memory cells of an integrated circuit, and also retrieval of information from the medium. The integrated circuit includes nonvolatile memory cells (416) capable of multilevel or analog voltage level storage. The integrated circuit may store or record information in analog or digital form, or both. Information is stored in and retrieved from the integrated circuit using a user-selected sampling frequency. The user'"'"'s selection of the sampling frequency is stored within the integrated circuit.

Claims

1-26. -26. (canceled)

27. A clock selection circuit for an integrated circuit comprising:

an external clock input;

an internal oscillator;

a prescaler coupled to the external clock input;

an internal clock divider coupled to the internal oscillator;

a selection circuit coupled to the select one of an output from the prescaler or an output of the internal clock divider; and

an activity detector to detect a clock signal at the external clock input, and when a clock signal is detected at the external clock input, provide a signal to the selection circuit to select the output from the prescaler.

28. The circuit of claim 27 wherein an output of the selection circuit is used as a sampling frequency for the integrated circuit.

29. The circuit of claim 27 wherein the internal oscillator generates an output frequency of about N Hertz, and the internal clock divider generates at its output a frequency greater than N Hertz.

30-47. -47. (canceled)