仅用两片集成电路便可构成具有多种功能的音频振荡器,其电路见图1。IC_1是贵州都匀(506信箱)的新产品,双时基集成电路FX556(5G7556),它的功能与两个5G1555等同。在图1中,IC_1的半片构成一个频率为2H_z的低频振荡器(由R_1、R_2和C_1定时),另外的半片构成可控型音频振荡器(由R_3、R_4和C_2定时)IC_2是上海无线电十四厂生产的CMOS集成电路,型号CC4051,是8通道模拟转换器,图2是它的逻辑符号图,表1给出其真值表。 Only two integrated circuits can be used to form a multi-function audio oscillator, the circuit shown in Figure 1. IC_1 is a new product from Duyun, Guizhou Province (506 mailboxes). Dual-time base integrated circuit FX556 (5G7556) has the same function as the two 5G1555. In Figure 1, the half-slice of IC_1 constitutes a low-frequency oscillator of 2H_z frequency (clocked by R_1, R_2 and C_1) and the other half forms the controllable audio oscillator (clocked by R_3, R_4 and C_2). IC_2 is the Shanghai radio Fourteen factory production of CMOS integrated circuits, model CC4051, is an 8-channel analog converter, Figure 2 is its logical symbol diagram, Table 1 gives its truth table.