Method and mechanism to prevent corruption of data

• US 6,316,916 B2
• Filed: 12/15/2000
• Issued: 11/13/2001
• Est. Priority Date: 12/17/1999
• Status: Expired due to Term

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Bohne, William Clifford
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/738,090
• Publication Number:
  US 20010030526A1
• Time in Patent Office: 333 Days
• Field of Search: 320/150, 320/137, 320/106, 320/107, 320/136, 320/165, 429/61, 429/62
• US Class Current: 320/150
• CPC Class Codes: H02J 7/00043 using switches, contacts or markings, e.g. optical, magnetic or barcode
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries

Abstract

A circuit for preventing corruption of battery-specific data transferred from a battery-specific data element to a battery charger when a battery is electrically coupled to both the battery charger and to a load includes a charger connection sensor and an interrupter circuit. The charger connection sensor is capable of sensing when the battery is connected to the battery charger. The interrupter circuit is responsive to the charger connection sensor. The interrupter circuit electrically couples the battery-specific data element to a load side battery-specific data node when the charger connection sensor indicates that the battery is not connected to the battery charger and electrically uncouples the battery-specific data element to the battery-specific data node accessible by the load when the charger connection sensor indicates that the battery is connected to the battery charger.

Claims

1. A circuit for preventing corruption of battery-specific data transferred from a battery-specific data element to a battery charger when a battery is electrically coupled to both the battery charger and to a load, comprising:

a. a charger connection sensor that is capable of sensing when the battery is connected to the battery charger; and

b. an interrupter circuit, responsive to the charger connection sensor, that electrically couples the battery-specific data element to a load side battery-specific data node when the charger connection sensor indicates that the battery is not connected to the battery charger and that electrically uncouples the battery-specific data element to the battery-specific data node accessible by the load when the charger connection sensor indicates that the battery is connected to the battery charger.

2. The apparatus of claim 1, wherein the battery charger comprises a pull-up resistor that electrically couples a pull-up node to a reference voltage when the battery is connected to the battery charger and wherein the charger connection sensor comprises:

a. a first resistor that electrically couples the pull-up node to a ground, so that the pull-up node has a first voltage when the first resistor is electrically coupled to the pull-up resistor and so that the pull-up node has a second voltage, different from the first voltage, when the first resistor is not electrically coupled to the pull-up resistor; and

b. a control switching element, having a gate electrically coupled to the pull-up node and a control node electrically coupled to the interrupter circuit so that the interrupter circuit electrically uncouples the battery-specific data element from the load side battery-specific data node when the pull-up node has the first voltage and so that the interrupter circuit electrically couples the battery-specific data element to the load side battery-specific data node when the pull-up node has the second voltage.

3. The apparatus of claim 2, wherein the first resistor comprises a negative coefficient thermistor.

4. The apparatus of claim 1, wherein the charger connection sensor generates a charger connection sensor output that is in a first state when the battery is connected to the battery charger and that is in a second state when the battery is not connected to the battery charger.

5. The apparatus of claim 4, wherein the interrupter circuit comprises:

a. a first field effect transistor having a first gate, a first source and a first drain, a first parasitic diode existing between the first source and the first drain, the first field effect transistor being biased so that parasitic current may flow though the first parasitic diode in only a first direction, the first drain being in series with a first selected one of the load side battery-specific data node or the battery-specific data element, the first gate being electrically coupled to the charger connection sensor output and the first field effect transistor being biased so that current is allowed to flow between the first source and the first drain when the charger connection sensor output is in the second state; and

b. a second field effect transistor having a second gate, a second source and a second drain, a second parasitic diode existing between the second source and the second drain, the second field effect transistor being biased so that parasitic current may flow through the second parasitic diode in only a second direction, different from the first direction, the second drain being in series with a second selected one of the load side battery-specific data node or the battery-specific data element, the second selected one of the load side battery-specific data node or the battery-specific data element being different from the first selected one of the load side battery-specific data node or the battery-specific data element, the second gate being electrically coupled to the charger connection sensor output and the second field effect transistor being biased so that current is allowed to flow between the second source and the second drain when the charger connection sensor output is in the second state.