Accurate persistent nodes

• US 9,367,794 B2
• Filed: 02/15/2013
• Issued: 06/14/2016
• Est. Priority Date: 05/06/2005
• Status: Active Grant

• Current Assignee: Zest Labs, Inc.
• Original Assignee: Intelleflex Corporation
• Inventors: Stewart, Roger Green
• Primary Examiner(s): Nguyen, Nam V
• Application Number:
  US13/768,809
• Publication Number:
  US 20130154806A1
• Time in Patent Office: 1,215 Days
• Field of Search: 340 101- 105, 340/572.5, 342/42, 702/63, 702/75, 702/78, 702/79
• US Class Current: 1/1
• CPC Class Codes: G05F 3/16 being semiconductor devices
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06M 3/02 for performing an operation at a predetermined value of the count, e.g. arresting a machine G06M3/04 takes precedence
• CPC Class Codes: H03F 3/45076 characterised by the way of implementation of the active amplifying circuit in the differential amplifier

Abstract

A calibrated gate biasing circuit according to one embodiment includes a switched capacitor precision resistor; and a voltage reference. An electronic circuit for initiating a change in state of a host device, according to another embodiment, includes a counter coupled to a host device, the counter counting at a fixed interval, wherein the counter is reset to zero upon receiving a command from a remote device, wherein the count is compared to a reference value, wherein the host device changes states if the count matches the reference value, wherein operation of the counter continues in spite of an interruption in power supply from a power source. Asymmetrical differential amplifiers are also disclosed, according to various embodiments.

Claims

1. A calibrated gate biasing circuit, comprising:

a switched capacitor precision resistor comprising at least two transistors and at least two corresponding capacitors, wherein a bias current flowing through the switched capacitor precision resistor is about 0.2 picoamperes (pA); and

a matrix of forward biased diodes coupled to an outlet of the switched capacitor precision resistor.

2. The circuit of claim 1, wherein the matrix of forward biased diodes is calibrated based on a reference frequency.

3. The circuit of claim 2, wherein the reference frequency is received from a remote device.

4. The circuit of claim 1, wherein the circuit is embodied on a Radio Frequency Identification (RFID) tag.

5. An RFID system, comprising:

an RFID tag implementing the circuit of claim 1; and

an RFID reader in communication with the RFID tag.