Overcurrent protection circuit, memory storage device and overcurrent protection method

A memory storage device, comprising:

• a connection interface unit configured to be connected to a host system;
• a rewritable non-volatile memory module;
• a memory control circuit unit connected to the connection interface unit and the rewritable non-volatile memory module;
• and
• an overcurrent protection circuit disposed in the connection interface unit, the rewritable non-volatile memory module, or the memory control circuit unit,
• wherein the overcurrent protection circuit is configured to:
• detect whether there is an overcurrent in a current flowing through a load switch in a state that a voltage difference between the two terminals of the load switch is within a first voltage region;
• generate a first node voltage in the state that the voltage difference between two terminals of the load switch is within the first voltage region, wherein the two terminals of the load switch are respectively connected to a first voltage and a second voltage;
• detect whether there is the overcurrent in the current flowing through the load switch in a state that the voltage difference between the two terminals of the load switch is within a second voltage region;
• generate a second node voltage in the state that the voltage difference between the two terminals of the load switch is within the second voltage region;
• and
• cut off the load switch according to at least one of the first node voltage and the second node voltage to perform an overcurrent protection,
• wherein the first voltage region covers a portion of a voltage range between a drive voltage and a reference ground voltage, the second voltage region covers an another portion of the voltage range between the drive voltage and the reference ground voltage, and the first voltage region and the second voltage region are at least partially overlapped,
• wherein the overcurrent protection circuit comprises:
• a first mirror circuit connected to the load switch;
• and
• a second mirror circuit connected to the load switch,
• wherein the first mirror circuit comprises:
• a first current mirror circuit connected to the load switch and configured to generate a first mirror current according to the current flowing through the load switch,
• wherein the second mirror circuit comprises:
• a second current mirror circuit connected to the load switch and configured to generate a second mirror current according to the current flowing through the load switch.

An overcurrent protection method, configured to control a load switch, the overcurrent protection method comprising:

• detecting whether there is an overcurrent in a current flowing through a load switch in a state that a voltage difference between the two terminals of the load switch is within a first voltage region;
• generating a first node voltage in the state that the voltage difference between two terminals of the load switch is within the first voltage region, wherein the two terminals of the load switch are respectively connected to a first voltage and a second voltage;
• generating a first mirror current according to the current flowing through the load switch via a first current mirror circuit of a first mirror circuit;
• detecting whether there is the overcurrent in the current flowing through the load switch in a state that the voltage difference between the two terminals of the load switch is within a second voltage region;
• generating a second node voltage in the state that the voltage difference between the two terminals of the load switch is within the second voltage region;
• generating a second mirror current according to the current flowing through the load switch via a second current mirror circuit of a second mirror circuit;
• and
• cutting off the load switch according to at least one of the first node voltage and the second node voltage to perform an overcurrent protection,
• wherein the first voltage region covers a portion of a voltage range between a drive voltage and a reference ground voltage, the second voltage region covers an another portion of the voltage range between the drive voltage and the reference ground voltage, and the first voltage region and the second voltage region are at least partially overlapped.