| 摘要 |
PURPOSE: A tracking signal processing circuit is provided to control a control current having a stable current value, consequently a central frequency can be properly controlled in a band pass filter by using a current controlled through a japping process. CONSTITUTION: A band pass filter has two operational amplifiers(OP1,OP2). 'gm' values of the operational amplifiers(OP1,OP2) are determined by currents flowing into transistors(Q41,Q42). The transistors(Q41,Q42) configure a current mirror with a transistor(Q43), and the current mirror is determined by a current flowing into the transistor(Q43). The current flowing into the transistor(Q43) is controlled through a japping process.
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