Managing startups of bandgap reference circuits in memory systems

A memory system comprising:

• a memory;
• a memory controller coupled to the memory;
• and
• a bandgap reference circuit coupled to the memory controller and configured to provide a bandgap reference voltage to the memory controller for performing one or more actions on the memory, the bandgap reference circuit comprising:
• a power supply switch configured to receive an original supply voltage and provide a controlled supply voltage controllable by an enabling signal;
• an operational amplifier configured to receive input voltages and the controlled supply voltage and output a gate control voltage;
• output circuitry configured to receive the gate control voltage from the operational amplifier and the controlled supply voltage from the power supply switch, provide the input voltages to the operational amplifier, and output an output voltage as the bandgap reference voltage;
• and
• initialization circuitry coupled to the power supply switch, the operational amplifier, and the output circuitry and configured to initialize the controlled supply voltage and the gate control voltage to a ground based on the enabling signal.

An integrated circuit comprising:

• a power supply switch configured to receive an enabling signal and an original supply voltage and to controllably output a controlled supply voltage at a power terminal with the controlled supply voltage at a first voltage when the enabling signal is in a first state and to have the power terminal grounded when the enabling signal is in a second state;
• an operational amplifier including a pair of input terminals, a voltage supply terminal coupled to the power terminal to receive the controlled supply voltage, and an output terminal to output a gate control voltage;
• output circuitry coupled to the output terminal of the operational amplifier to receive the gate control voltage and coupled to the power terminal to receive the controlled supply voltage, the output circuitry configured to generate and feedback a pair of input voltages to the pair of input terminals of the operational amplifier, and to output a reference voltage;
• and
• initialization circuitry coupled to the power supply switch, the operational amplifier, and the output circuitry, and configured to receive the enabling signal and to drive the controlled supply voltage and the gate control voltage to ground when the enabling signal is in the second state.