Current generator

A current generator, comprising:

• a bandgap circuit outputting a bandgap reference voltage, the bandgap circuit comprising:
• first, second and third bipolar junction transistors (BJT) having their collectors connected together to a negative power supply;
• first, second and third MOS transistors having their sources connected together to a positive power supply and respectively biased to flow first, second and third internal currents from their drains into the emitters of the first, second and third BJTs;
• first and second resistors respectively connected between the emitter of the second BJT and the drain of the second MOS transistor and between the emitter of the third BJT and the drain of the third MOS transistor;
• and
• a differential amplifier generating a bias voltage according to the voltages at the drains of the first and second MOS transistors for biasing of the first, second and third MOS transistors,
• wherein the voltage at the drain of the third MOS transistor is output as the bandgap reference voltage;
• an operational amplifier having a positive input receiving the bandgap reference voltage, a negative input, and an output connected to the negative input to obtain an output voltage substantially equal to the bandgap reference voltage;
• and
• an output resistor connected to the output of the operational amplifier serially to generate an output current flowing through the output resistor.