Circuit arrangement for controlling and detecting the load current through a load
AssigneeInfineon Technologies AG
InventorsAlfons Graf, Rainald Sander
Life of this patent
Estimating the term…
Abstract
Circuit arrangement for controlling the current flow through a load in the case of detection of the current flow according to the current sense principle. The circuit arrangement has a load transistor and a plurality of auxiliary transistors of identical type, which have a control terminal which is connected or can be connected to the control terminal of the load transistor. In the case of the circuit arrangement according to the invention, provision is made of a switching mechanism by which the auxiliary transistors, optionally or depending on the load current or depending on a load path voltage dropped across the load path of the load transistor, can be connected in parallel individually or as a plurality.
Claims18
A circuit arrangement for controlling and detecting a load current through a load, the circuit arrangement comprising:
- a load transistor having a control terminal, a load path, a first load path terminal and a second load path terminal, the load being connected in series with the load path of the load transistor to define a series circuit, this series circuit being connected between terminals for a supply potential and a reference potential;
- at least one auxiliary transistor having a control terminal, a load path, a first load path terminal and a second load path terminal;
- a current measuring circuit having a first and second input respectively connected to the first load path terminal of the load transistor and to the first load path terminal of the at least one auxiliary transistor and having an output, at which a signal dependent on the load current can be tapped off;
- a drive unit connected to the control terminal of the load transistor;
- at least one second auxiliary transistor, which is of identical type to the at least one auxiliary transistor, the at least one second auxiliary transistor having a control terminal, which is controllably connected to the control terminal of the load transistor, and having a load path;
- switching means for controllably connecting the load path of the at least one second auxiliary transistor in parallel with the at least one auxiliary transistor, depending on the load current or depending on a load path voltage obtained across the load path of the load transistor;
- and
- detection means that detect if the load current falls below a threshold and thereupon generate an output signal that is applied to the switching means.
Dependencies are inferred from the claim text.