Systems and methods for overcurrent detection of charge pumps

An overcurrent detector for a charging path of a charge pump, the charging path including a switch associated with a switch on-resistance value, the charge pump being configured to receive an input voltage and generate an output voltage to charge a battery, the overcurrent detector comprising:

• a reference unit biased to the output voltage and configured to generate a reference voltage representing a predetermined threshold current for the switch of the charging path;
• a detection unit coupled to the reference unit and configured to generate a sensing voltage representing a charging current that flows through the switch of the charging path;
• and
• an output unit configured to generate an over-current-protection signal based at least in part on the reference voltage and the sensing voltage;
• wherein the output unit is further configured to, in response to the sensing voltage exceeding the reference voltage, generate the over-current-protection signal that indicates the charging current exceeds the predetermined threshold current;
• wherein the overcurrent detector is configured to periodically perform overcurrent detection for the charging path of the charge pump;
• wherein the overcurrent detector is further configured to:
• perform the overcurrent detection for the charging path of the charge pump during a first charging duration of each period of a periodic clock signal;
• and
• not perform the overcurrent detection for the charging path of the charge pump during a second charging duration of the each period of the periodic clock signal;
• wherein the each period of the periodic clock signal includes the first charging duration and the second charging duration.

An overcurrent detector for a charging path of a charge pump, the charging path including a switch associated with a switch on-resistance value, the charge pump being configured to receive an input voltage and generate an output voltage to charge a battery, the overcurrent detector comprising:

• a reference unit biased to the output voltage and configured to generate a reference voltage representing a predetermined threshold current for the switch of the charging path;
• a detection unit coupled to the reference unit and configured to generate a sensing voltage representing a charging current that flows through the switch of the charging path;
• and
• an output unit configured to generate an over-current-protection signal based at least in part on the reference voltage and the sensing voltage;
• wherein the output unit is further configured to, in response to the sensing voltage exceeding the reference voltage, generate the over-current-protection signal that indicates the charging current exceeds the predetermined threshold current;
• wherein the overcurrent detector is configured to periodically perform overcurrent detection for the charging path of the charge pump;
• wherein the overcurrent detector is further configured to:
• not perform the overcurrent detection for the charging path of the charge pump during a first charging duration of each period of a periodic clock signal;
• and
• perform the overcurrent detection for the charging path of the charge pump during a second charging duration of the each period of the periodic clock signal;
• wherein the each period of the periodic clock signal includes the first charging duration and the second charging duration.

An overcurrent detection method for a charging path of a charge pump, the charging path including a switch associated with a switch on-resistance value, the charge pump being configured to receive an input voltage and generate an output voltage to charge a battery, the overcurrent detection method comprising:

• generating a reference voltage representing a predetermined threshold current for the switch of the charging path based at least in part on the output voltage;
• generating a sensing voltage representing a charging current that flows through the switch of the charging path;
• processing information associated with the reference voltage and the sensing voltage;
• generating an over-current-protection signal based at least in part on the reference voltage and the sensing voltage;
• and
• performing overcurrent detection for the charging path of the charge pump during each period of a periodic clock signal;
• wherein the generating an over-current-protection signal based at least in part on the reference voltage and the sensing voltage includes:
• in response to the sensing voltage exceeding the reference voltage, generating the over-current-protection signal that indicates the charging current exceeds the predetermined threshold current;
• wherein the each period of the periodic clock signal includes the first charging duration and the second charging duration.