Patent ID: 7102335
Filing Date: 2006-09-05
Classification: G11C,H03F

Abstract:
1. A rail—rail current sense amplifier for sensing current through a current sense device coupled to a battery node that couples to a removable battery, comprising: a low voltage current sense amplifier circuit that develops a first current that is proportional to current through the current sense device for low voltages up to an upper voltage threshold; a high voltage current sense amplifier circuit that develops a second current that is proportional to current through the current sense device for high voltages down to a lower voltage threshold that is lower than said upper voltage threshold; a first resistive device that develops a current sense output voltage; and a selection circuit, coupled to said low and high voltage current sense amplifier circuits and said first resistive device, that selectively applies said first current to said first resistive device for low voltages up to said upper voltage threshold, and that selectively applies said second current to said first resistive device for high voltages down to said lower voltage threshold.