{
  "$type": "site.standard.document",
  "description": "Disclosed is a method for charging a battery and circuitry for performing the method. The method includes steps of: (a) generating a charging current (Ich) for a battery; (b) generating a replica current (Irep) of Ich, where Irep=Ich/N, where N > 1; (c) measuring a voltage drop induced by Irep…",
  "path": "/patents/1103122",
  "publishedAt": "2002-07-17T00:00:00.000Z",
  "site": "at://did:plc:oql6ds5vnff4ugar6rruliwd/site.standard.publication/3mn3ohu7oxx5w",
  "tags": [
    "G01R31/382",
    "NOKIA CORP [FI]"
  ],
  "textContent": "Disclosed is a method for charging a battery and circuitry for performing the method. The method includes steps of: (a) generating a charging current (Ich) for a battery; (b) generating a replica current (Irep) of Ich, where Irep=Ich/N, where N > 1; (c) measuring a voltage drop induced by Irep across a measurement resistance; and (d) using the measured voltage drop for controlling a magnitude of Ich. Preferably N is greater than about 10, more preferably N is greater than about 100, and in the most preferred embodiment N is in a range of about 100 to about 1000. The step of generating the charging current (Ich) includes a step of operating a first device having an input node coupled to a source of charging current, the step of generating the replica current (Irep) includes a step of operating a second device having an input node coupled to the source of charging current; wherein the first device and the second device are both driven with the same control signal. The control signal may be a pulse width modulated signal having a pulse width that is controlled as a function of the measured voltage drop across the measurement resistance, or a DC voltage having an adjustable voltage value. In the preferred embodiment the step of generating the replica current (Irep) includes a step of operating a servo loop to force a potential appearing at an output node of the second device to equal a potential appearing at an output node of the first device. A battery discharge measurement circuit is also disclosed, and operates in accordance with the same principles as the battery charging circuit.",
  "title": "Battery charging circuit"
}