Patent ID: 7468619
Filing Date: 2008-12-23
Classification: H03K

Abstract:
1. A load drive device for driving an electrical load connected between a higher voltage terminal and a lower voltage terminal, the load drive device comprising: a high-side transistor connected between the higher voltage terminal and the electrical load; a low-side transistor connected between the electrical load and the lower voltage terminal; first full-on means for causing the high-side transistor to operate in a first full-on control mode where the high-side transistor is fully tuned on; first constant means for causing the high-side transistor to operate in a first constant control mode where the high-side transistor is controlled so that a load current flowing through the electrical load is constant; second full-on means for causing the low-side transistor to operate in a second full-on control mode where the low-side transistor is fully tuned on; second constant means for causing the low-side transistor to operate in a second constant control mode where the low-side transistor is controlled so that the load current flowing through the electrical load is constant; and switching means for switching a state from a first state to a second state and/or from the second state to the first state, wherein in the first state, the high-side transistor operates in the first constant control mode and the low-side transistor operates in the second full-on control mode, and in the second state, the high-side transistor operates in the first full-on control mode and the low-side transistor operates in the second constant control mode.