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发明公开
CN106992667A 一种恒流驱动电路 审中-实审

一种恒流驱动电路
摘要：
本发明公开了一种恒流驱动电路，负载L1的一端与负载电源VCC1和续流二极管D1的阴极连接，负载L1的另一端与取样电阻R1、R2的一端连接，取样电阻R2的另一端与隔离芯片U1的A脚连接，取样电阻R1另一端与续流二极管D1的阳极、U1的K脚和开关管N1的漏极连接，U1的C脚与电阻R5、R6的一端和控制芯片U3的INPUT端连接，电阻R5另一端与电源VCC3连接，电阻R6另一端和U1的E脚接地，控制芯片U3的OUTPUT脚与隔离芯片U2的K脚连接，隔离芯片U2的A脚与电阻R7一端连接，电阻R7另一端与电源VCC3连接，隔离芯片U2的VCC脚与电源VCC2连接，隔离芯片U2的OUT脚与开关管N1的栅极连接，隔离芯片U2的GND脚和开关管N1的源极接地。本发明结构简单、驱动电流控制方便且成本较低。
摘要（英）：

The present invention discloses a constant current driving circuit. One end of a load L1 is connected to a load power source VCC1 and the cathode of a freewheeling diode D1, the other end of the load L1 is connected to one ends of sampling resistors R1 and R2, the other end of the sampling resistor R2 is connected to the A pin of an isolation chip U1, the other end of the sampling resistor R1 is connected with the anode of the freewheeling diode D1, the K pin of the U1 and the drain of a switch N1, the C pin of the U1 is connected with one ends of the resistors R5, R6 and the INPUT terminal of a control chip U3, the other end of the resistor R5 is connected with a power supply VCC3, the other end of the resistor R6 and the E pin of the U1 are grounded, the OUTPUT pin of the control chip U3 and the K pin of the isolation chip U2 are connected, the A pin of an isolated chip U2 is connected with one end of a resistor R7, the other end of the resistor R7 is connected with the power supply VCC3, the VCC pin of the isolation chip U2 is connected with a power supply VCC2, the OUT pin of the isolation chip U2 is connected with the gate of the switch N1, and the GND pin of the isolation chip U2 and the source of the switch N1 are grounded. The structure is simple, the driving current control is convenient, and the cost is low.

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