US 6,307,726 B1 · System to control the output current with temperature through a controllable current limiting circuit

Abstract

A controllable current limiting circuit (30) that, when used with a low precision current limiting circuit (10), will limit the current of the output driver transistor M1 to a relatively flat response over a broad temperature range. The current is limited by setting the voltage across a resistance, R1, to a certain value. To overcome temperature induced variations in this voltage, the compensation circuit (20) generates a current that varies with temperature. This current is injected into a terminal of the resistance, R1. This current is generated in such as a manner to ensure that the current flowing in the output driver transistor M1 is relatively constant over a wide temperature range.

Claims6

Dependent claims

A current limiting circuit comprising:

(a) a first IGFET for conducting a current, the largest amplitude of which is to be limited to a preselected value,
(b) a resistance operatively connected to a source of said IGFET,
(c) a circuit for limiting the voltage across said resistance, and
(d) a compensation circuit for injecting a compensation current into a terminal of said resistance, said compensation current being adapted to correct for temperature induced variations in the output of said current limiting circuit,
(e) a second IGFET wherein said first IGFET is a sensefet of said second IGFIT, the current in said second IGFET being greater than the current in said first IGFET.

2 more elements

Dependencies are inferred from the claim text.

System to control the output current with temperature through a controllable current limiting circuit

Life of this patent

System to control the output current with temperature through a controllable current limiting circuit

Life of this patent

Abstract

Claims6