Floating gate digital-to-analog converter

• US 20080068242A1
• Filed: 09/17/2007
• Published: 03/20/2008
• Est. Priority Date: 11/30/2001
• Status: Active Grant

• Current Assignee: Second Sight Medical Products, Inc.
• Original Assignee: Second Sight Medical Products, Inc.
• Inventors: Little, James, Tang, Kea-Tiong, Dai, Rongqing
• Granted Patent: US 7,482,957 B2
• Time in Patent Office: Days
• US Class Current: 341/144
• CPC Class Codes: H03M 1/007 among different resolutions
• CPC Class Codes: H03M 1/1061 using digitally programmable trimming circuits
• CPC Class Codes: H03M 1/662 Multiplexed conversion systems
• CPC Class Codes: H03M 1/70 Automatic control for modifying converter range
• CPC Class Codes: H03M 1/742 using current sources as quantisation value generators
• CPC Class Codes: H03M 1/745 with weighted currents

Abstract

The present invention provides a DAC constructed from a series of floating gate devices which are programmable to a series of predetermined values. Addressing one or more of the programmed floating gate devices will select from a wide variety of analog outputs. Reprogramming the floating gate devices, can provide a different variety of analog outputs. For example, the floating gate devices can be preprogrammed to a different range of outputs matching a range of perceptible signals.

Claims

1. An electrical stimulator for implanting in a human body comprising:

a digital-to-analogue converter having a plurality of floating gate devices for providing analogue current outputs;

an output device coupling the total current output from the floating gate devices to a stimulator electrode;

a floating gate device controller for programming the output current for each floating gate device, wherein each floating gate device is addressable and can be activated individually or in combination via a further controller to provide a desired total current output to the electrode.

3. The electrical stimulator according to claim 1, comprising an internal digital system which produces the digital address signal and which is for activating the floating gate devices.

5. The electrical stimulator according to claim 1, comprising a driver coupled between the output device and the electrode.

7. The electrical stimulator according to claim 1, comprising an internal digital system which produces the digital access signal and which is for activating the floating gate devices;

and

a driver coupled between the output device and the electrode.

9. The electrical stimulator according to claim 1, comprising a receiver coupled to the floating gate programme controller for receiving a signal from an external transmitter with stimulation information.

11. The electrical stimulator according to claim 1, comprising an internal digital system which produces the digital address signal and which is for activating the floating gate devices;

and

a receiver coupled to the floating gate programme controller for receiving a signal from an external transmitter with stimulation information.

13. The electrical stimulator according to claim 1, comprising a driver coupled between the output device and the electrode;

and

a receiver coupled to the floating gate programme controller for receiving a signal from an external transmitter with stimulation information.

15. The electrical stimulator according to claim 1, comprising an internal digital system which produces the digital address signal and which is for activating the floating gate devices;

a driver coupled between the output device and the electrode; and

a receiver coupled to the floating gate programme controller for receiving a signal from an external transmitter with stimulation information.

17. The electrical stimulator according to claim 1, wherein the total current output from the floating gate devices is coupled to the stimulator electrode through the output device.

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