Device for measurement of the electrical consumption of a portable data- or signal-processing terminal

• US 6,392,399 B1
• Filed: 01/11/2000
• Issued: 05/21/2002
• Est. Priority Date: 01/22/1999
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Sagem SA (Safran SA)
• Inventors: Bernard, Robert
• Primary Examiner(s): Karlsen, Ernest
• Assistant Examiner(s): TANG, MINH NHUT
• Application Number:
  US09/481,029
• Time in Patent Office: 861 Days
• Field of Search: 324/103.R, 324/426, 324/428, 324/433, 324/111, 324/141, 320/132, 320/136, 320/106, 340/636, 327/101, 327/336, 341/167, 341/155, 341/164, 341/165
• US Class Current: 324/103.00R
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3828 using current integration

Abstract

The device for measurement of current exchanged between a battery (1) and electrical circuits (19) of a portable telephone includes a current sensor (21), connecting the battery (1) to the circuits (19), connected to a first input (22) of first integrating circuits (22-27), integrating the current measurement and controlling a comparator (28, 29, 34) detecting the crossing of a high threshold (Vs+) through the integral of the current and applying to a second input (23) of the first integrating circuits (22-27) a calibrated feedback signal to recall below the high threshold (Vs+), second integrating circuits (12-17) to integrate the feedback signals, providing a measurement of the current exchanged. The invention applies well to mobile telephones.

Claims

1. A device for measurement of current exchanged between an energy supply source and electric circuits of a portable data- or signal- processing terminal, comprising:

a current-measurement sensor connected between the source and sad circuits;

a first integrating means with an output and a first input connected to the sensors said first integrating means arranged to integrate the measurement of the current;

a first comparator means with a first input connected to the output of the first integrating means and an output, said comparator means arranged to detect the crossing of high threshold (Vs+) through the integral of the current;

a second input of fist integrating means arranged to receive a calibrated feedback signal from the output of said comparator means to recall below the high threshold (Vs+);

a second integrating means provided to integrate the feedback signal, in order to provide a measurement of the current exchanged;

a second comparator means to detect the crossing of a low threshold (Vs−

) output from the first integrating means and to apply, as a result, to a third input of the first integrating means a calibrated feedback signal to recall above the low threshold (Vs−

); and

a third integrating means to integrate the feedback signals from the second comparator so as to provide a measurement of the current considered, and a subtracting means are provided, at the outputs of the second and third integrating means, for their respective measurements in order to provide a measurement of the balance of consumption.

2. The device according to claim 1, in which the comparator means includes, at the output, a feedback signal calibration means comprising an interval timer arranged to provide a pulse of calibrated duration.

3. The device according to claim 2, in which the calibration means include a switch arranged in order to be controlled by the interval timer and connecting a source of predetermined voltage to the second input of the first integrating means.

4. The device according to claim 1, in which the sensor circuit is connected to a pulse-counting block connected to a memory storing the result of each counting and provided as part of the source.

5. The device according to claim 1 in which the first integrating means functions in a range limited by the two threshold voltages, high Vs+and low Vs−

, and centered on the ground.

6. The device according to claim 2, in which the interval timer is digital and comprises a counter to provide calibrated pulses, controlled by a comparator through a synchronization circuit arranged, in phase opposition with a clock to advance the counter, so as to sample and store an active output state of the comparator.

7. The device according to claim 6, in which the synchronization circuit is provided for sampling the state of the counter, arranged, in phase opposition with the clock, so as to detect a particular state of the counter and then reset the counter and the synchronization circuit to a resting state.

8. A portable data- or signal-processing terminal that comprises the current measurement device of claim 1.

9. The terminal according to claim 8, in which the second integrating means are arranged so as to provide different measurements of current, depending on the state of operation of the terminal.