Patent ID: 7142436
Filing Date: 2006-11-28
Classification: H02M,H03K

Abstract:
1. A bi-directionally load current driving circuit comprising: a voltage source; a bridge circuit comprising a first switch, a second switch, a third switch, and a fourth switch, wherein said voltage source provides a supply voltage to said first switch, said second switch, said third switch and said fourth switch, which are electrically connected to form two arms, said two arms has a first output terminal and a second output terminal individually, and said first output terminal and said second output terminal are connected to a load; a first differential amplifier comprising a first input terminal, a second input terminal, and an output terminal electrically connected to an input terminal of said first switch; a second differential amplifier comprising a first input terminal, a second input terminal, and an output terminal electrically connected to an input terminal of said second switch; a third differential amplifier comprising a first input terminal, a second input terminal, and an output terminal electrically connected to an input terminal of said third switch; a fourth differential amplifier comprising a first input terminal, a second input terminal, and an output terminal electrically connected to an input terminal of said fourth switch; a first feedback network connected to said first input terminal of said first differential amplifier and said first input terminal of said second differential amplifier; a second feedback network comprising a control voltage connected to said second feedback network, which is connected to said second input terminal of said first differential amplifier, said second input terminal of said second differential amplifier, and said first output terminal of said bridge circuit; a third feedback network connected to said first input terminal of said third differential amplifier, said first input terminal of said fourth differential amplifier, and said first output terminal and said second output terminal of said bridge circuit; and a fourth feedback network connected to said second input terminal of said third differential amplifier and said second input terminal of said fourth differential amplifier; wherein a current flowing through the load is unrelated to said supply voltage; instead, said current is proportional to said control voltage.