VcC 4B 4A 4Y 3b 3A 3Y VCc 2D 2C 2B NC 2A 2Y 141312111098 141312111098 74LS00 74LS20 1234567 1234567 1A 1B 1Y 2A 2B 2Y GND 1A 1B NC 1C ID 1Y GND 图 图b VCc 2Y 2D 2 2B 2A NC Vcc 6B 6Y 5B 5Y 4B 4Y 141312111098 141312111098 CD4002 74L04 1234567 1234567 1Y 1A 1B 1C 1D NC GND 1A 1Y 2A 2Y 3A 3Y GND 图d