Semiconductor device for battery control and battery pack

Abstract

A semiconductor device for battery control includes a CPU, a first bus coupled to the CPU, a second bus not coupled to the CPU, and a protective function circuit for protecting a battery from stress applied thereto. The semiconductor device also includes a non-volatile memory storing trimming data, a trimming circuit to perform trimming required to allow the protective function circuit to exert a protective function, and a bus control circuit capable of selectively coupling the first bus and the second bus to the non-volatile memory. The semiconductor device further includes a transfer logic circuit which causes, by making the bus control circuit select the second bus, a trimming data transfer path leading from the non-volatile memory to the trimming circuit to be formed and the trimming data stored in the non-volatile memory to be transferred to the trimming circuit without involving the CPU.

1 - 8 . (canceled) 
     
     
         9 . A battery control semiconductor device, comprising:
 a voltage measuring circuit configured to measure a voltage of a battery;   a processor configured to control charging of the battery based on the voltage of the battery;   a non-volatile memory configured to store a first value;   a protection circuit including a voltage circuit which generates a reference voltage and a comparison circuit, the protection circuit being configured to halt the charging of the battery based on a comparison result of the voltage of the battery with the reference voltage; and   a trimming circuit configured to load the first value from the non-volatile memory and change the reference voltage based on the first value.   
     
     
         10 . A battery control semiconductor device according to  claim 9 ,
 wherein the non-volatile memory has a first area which is accessible by the processor and a second area which is not accessible by the processor, and   wherein the first value is stored in the second area.   
     
     
         11 . A battery control semiconductor device, comprising:
 a voltage measuring circuit configured to measure a voltage of a battery;   a current measuring circuit configured to measure a current of the battery;   a processor configured to control charging of the battery based on the voltage of the battery;   a non-volatile memory configured to store a first value and a second value;   a protection circuit including a first voltage circuit which generates a first reference voltage, a second voltage circuit which generates a second reference voltage, and a comparison circuit,   the protection circuit being configured to halt the charging of the battery based on a comparison result of the voltage of the battery with the first reference voltage or a comparison result of a voltage corresponding to the current of the battery with the second reference voltage; and   a trimming circuit configured to load the first value and the second value from the non-volatile memory and change the first reference voltage and the second reference voltage based on the first value and second value, respectively.   
     
     
         12 . A battery control semiconductor device according to  claim 11 ,
 wherein the non-volatile memory has a first area which is accessible by the processor and a second area which is not accessible by the processor, and   wherein the first value is stored in the second area.   
     
     
         13 . A method of charging a battery by a battery charging system including a processor, a trimming circuit and a non-volatile memory, the method comprising the steps of:
 (1) loading a first value from the non-volatile memory to the trimming circuit;   (2) setting a reference voltage based on the first value by the trimming circuit;   (3) measuring a voltage of the battery;   (4) commencing to charge the battery under control of the processor when the voltage of the battery is lower than a predetermined value;   (5) continuing to charge the battery until the voltage of the battery reaches the predetermined value;   (6) comparing the voltage of the battery with the reference voltage; and   (7) halting the charging of the battery when the voltage of the battery exceeds the reference voltage.   
     
     
         14 . A method of charging a battery by a battery charging system according to  claim 13 ,
 wherein the non-volatile memory has a first area which is accessible by the processor and a second area which is not accessible by the processor, and   wherein the first value is stored in the second area.