Automatic current and reference gain control for wide range current control,申请号US201314096407-传众专利搜索

Automatic current and reference gain control for wide range current control

申请公布号：US9363862(B1)

申请号：US201314096407

申请日期：2013.12.04

申请公布日期：2016.06.07

申请人：

Universal Lighting Technologies

发明人：Xiong Wei;Ungacta Candice;Dernovsek John J.

分类号：G05F1/00;H05B37/02;H05B39/04;H05B41/36;G05F1/10

主分类号：G05F1/00

代理机构：

Patterson Intellectual Property Law, P.C.

代理人：Patterson Intellectual Property Law, P.C. ;Patterson Mark J.

地址：Madison AL US

摘要：A constant current source has an increased differential amplifier gain at low output currents and a decreased differential amplifier gain at high output currents. The differential amplifier amplifies a sensed output current of the constant current source. A gain control circuit scales a reference current in conjunction with the gain applied to the sensed output current to maintain stable operation of the constant current source. The constant current source may be used in a driver circuit to provide power to a light source (e.g., an LED light).

主权项：1. A constant current driver circuit comprising: a current source tank circuit configured to receive power from a power source and provide an output current to a load as a function of a control signal; the current source tank circuit including a circuit ground; a controller having an output current sensing input, a reference current input, and a control signal output; the control signal output is configured to provide the control signal to the current source tank circuit; the controller is configured to adjust the control signal as a function of a sensed output current received at the output current sensing input and a sensed reference current received at the reference current input; an output current sensing circuit operable to sense the output current provided by the current source tank circuit to the load and provide an amplified current sensing signal to the output current sensing input of the controller; a gain control circuit operable to receive a reference current signal,adjust a gain of the output current sensing circuit as a function of the received reference current signal, andprovide a modified reference current signal to the reference current input of the controller as a function of the received reference current signal; and the output current sensing circuit comprises a current sensing resistor having a first terminal configured to connect to the load and a second terminal connected to the circuit ground,a current sensing amplifier having an inverting input, a non-inverting input, and an output connected to the output current sensing input of the controller,a first resistor connected between the inverting input of the current sensing amplifier and the output of the current sensing amplifier, anda second resistor connected between the inverting input of the current sensing amplifier and the circuit ground.