Abstract: A constant current generation circuit for optocoupler isolation amplifier and a current precision adjustment method are provided. The constant current generation circuit includes a start circuit, a current generation circuit and a precision adjustment and output circuit integrated into a same substrate. The start circuit can generate and output a first start current and a second start current. The current generation circuit includes a negative temperature change rate current generation circuit connected to a first start current output and a positive temperature change rate current generation circuit connected to a second start current output. The precision adjustment and output circuit outputs constant current meeting application requirements of optocoupler isolation amplifier by adjusting proportional precision of two currents output from a current generation circuit.

Abstract: Disclosed is a circuit for shifting a fixed ground level to a floating ground level in a motor drive system, including a floating ground high level line, a floating ground output level line, a floating ground low level line, a normal input level line, and a normal ground line that are used for characterizing an application detail. The circuit includes a controlled switching current source, a first upper current rectifier, a second upper current rectifier, a lower current rectifier, and an amplifying and shaping circuit that are integrated on a same substrate.

Abstract: Disclosed is a circuit for converting a temperature change amount into a voltage change amount in a motor drive system, including a positive temperature change rate voltage generation module, a circuit bias module, and a temperature detection module that are integrated on a same substrate. An external power supply voltage is processed by the positive temperature change rate voltage generation module and the circuit bias module, and then inputted to the temperature detection module. The temperature detection module detects in real time the temperature change amount in the motor drive system, convert the temperature change amount into the voltage change amount, and transfer the voltage change amount to the circuit bias module, to allow the circuit bias module to output the voltage change amount. In this way, the conversion from the temperature change amount into the voltage change amount is realized.

Abstract: The present disclosure provides a start-up initialization circuit of motor drive system, including a power amplitude detecting and internal power supply module, a controlled delay module, a waveform shaping module and a power supply judging and adjusting module integrated on a same substrate, configured to detect and manage a voltage change of each node of a drive system in real time to cause a motor drive system to realize a start-up initialization process transit from an off state to a normal working state. The present disclosure finally forms the start-up initialization circuit of motor drive system by integrating the power amplitude detecting and internal power supply module, the controlled delay module, the waveform shaping module and the power supply judging and adjusting module and integrating on a single chip, which greatly ensures the reliability of power on and start-up of the motor drive system.