Control method of hybrid power battery charger

Abstract

A power supply system and method for operating same. The power supply system is connectable to receive power from an adapter and supply power to a load. The power supply system includes a rechargeable battery, a buck mode circuit, and a boost mode circuit. A switching circuit switches between the buck mode circuit and boost mode circuit for supplying power to the load. If the power required by the load reaches a first predetermined level related to an adapter overload condition for a first predetermined time, the switching circuit disconnects said buck mode circuit from the load and connects the rechargeable battery and the boost mode circuit to said load. The first predetermined level may be established by a first predetermined percent of the current of a dynamic power management level established by the load, which is related to a power level below that which can be provided by the adapter.

1 . A power supply system connectable to receive power from an adapter and supply power to a load, comprising:
 a rechargeable battery;   a buck mode circuit;   a boost mode circuit;   and a switching circuit for switching between said buck mode circuit and boost mode circuit for supplying power to the load;   wherein if the power required by the load reaches a first predetermined level related to an adapter overload condition for a first predetermined time, said switching circuit disconnects said buck mode circuit from said load and connects said rechargeable battery and said boost mode circuit to said load.   
     
     
         2 . The power supply system of  claim 1  wherein said first predetermined level is established by a first predetermined percent of the current of a dynamic power management level established by the load, which is related to a power level below that which can be provided by the adapter. 
     
     
         3 . The power supply system of  claim 2  wherein said first predetermined percent of the current of a dynamic power management level established by the load is about 105%. 
     
     
         4 . The power supply system of  claim 1  wherein if the power required by the load is below a second predetermined level related to the adapter overload condition for a second predetermined time and the boost mode circuit and rechargeable battery are connected to the load, said boost mode circuit and said rechargeable battery are disconnected from the load and said buck mode circuit is started. 
     
     
         5 . The power supply system of  claim 4  wherein if the power required by the load is below a third predetermined level related to the adapter overload condition and the boost mode circuit and rechargeable battery are connected to the load, said boost mode circuit and said rechargeable battery are disconnected from the load and said buck mode circuit is started, said third predetermined level being less than said second predetermined level. 
     
     
         6 . In a power supply system connectable to a load, said power supply system having a rechargeable battery, a charging circuit, and an adapter connectable to receive power from a power supply source, said charging circuit comprising:
 buck mode circuitry for selectively supplying power to the load in a normal operating mode;   boost mode circuitry for selectively supplying power to the load in an adapter overload operating mode;   and switching circuitry for switching between said buck mode circuitry and boost mode circuitry;   wherein if the power required by the load reaches an adapter overload condition, said charging circuit shuts down, and waits a predetermined time;   wherein after the predetermined time, the charging circuit checks to determine whether the adapter overload condition still exists;   wherein if the adapter overload is still exists, said charging circuit changes from said buck mode circuitry to said boost mode circuitry and connects said battery to the load to provide additional power to the load.   
     
     
         7 . The power supply system of  claim 6  wherein said check to determine whether the adapter is still in the adapter overload condition is based on a system current. 
     
     
         8 . The power supply system of  claim 6  wherein said adapter overload condition is sensed by a programmable current threshold circuit. 
     
     
         9 . The power supply system of  claim 6  further comprising an adapter over-voltage protection circuit to disable the boost mode circuitry to prevent said boost mode circuitry from generating too high of a voltage on the load. 
     
     
         10 . The power supply system of  claim 6  further comprising a watchdog timer configured to change from said boost mode circuitry to said buck mode circuitry after a preset time. 
     
     
         11 . The power supply system of  claim 6  further comprising a control loop saturation detecting circuit to stop a boost mode operation if a control loop saturates and an adapter current is above a predetermined level. 
     
     
         12 . A method for operating a charger circuit having a rechargeable battery, a buck mode circuit, and a boost mode circuit, comprising:
 operating said buck mode circuit to provide power to a load in a normal operating mode;   sensing an input current to said charger circuit;   if said input current exceeds a first predetermined percent of a current of a dynamic power management level established by the load, shutting down the charger circuit for a first predetermined time;   and if said input current continues to exceed the first predetermined percent of a current of a dynamic power management level established by the load after the first predetermined time, starting the boost mode circuit and connecting the rechargeable battery to provide power to the load.   
     
     
         13 . The method of  claim 12  wherein said first predetermined time is at least 100 μs. 
     
     
         14 . The method of  claim 12  wherein said dynamic power management level is an input current level established to operate said load in a manner to protect said adapter from an overload condition. 
     
     
         15 . The method of  claim 12  wherein if the input current is less than a first predetermined level, stopping said boost mode circuit, disconnecting said rechargeable battery from the load, and starting said buck mode circuit. 
     
     
         16 . The method of  claim 15  wherein said predetermined amount is less than about 1 A for a 10 milliohm sensing resistor. 
     
     
         17 . The method of  claim 15  wherein if the input current is above said first predetermined level and less than a second predetermined percent of the current of a dynamic power management level established by the load for a second predetermined time, stopping said boost mode circuit, disconnecting said rechargeable battery from the load, and starting said buck mode circuit. 
     
     
         18 . The method of  claim 17  wherein said second predetermined time is about 1 ms. 
     
     
         19 . The method of  claim 17  wherein said first predetermined amount is greater than 1 A for a 10 milliohm sensing resistor. 
     
     
         20 . The method of  claim 17  wherein said second predetermined percent is less than about 93 percent of the dynamic power management level established by the load.