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闪光存贮μcs,由于其价廉和使用灵活,正受到广泛的应用。例如AT8051兼容的μcs,就可从40脚依次下降替换到20脚的各种闪光存贮μcs器件。更新的闪光存贮μcs器件,还需要要提供适于闪光存贮编程的工具,例如AT89C2051在实际编程时,它的RST引脚上就需要三种电平的编程电压:TTL逻辑0、逻辑1和12V的脉冲电压。附图电路,仅用了两只晶体管和很少的电阻器,就能提供给AT8051μCS闪光存贮编程用的三种电平的系列电压。 该电路采用12V稳压电源。电路中的晶体管Q1和Q2选用小信号的高速NPN型管。电阻R1和R2选用的精变为1％的,其余电阻可用精变为5％的碳膜电
Flash memory μcs, due to its low cost and ease of use, is in widespread use. For example, the AT8051 compatible μcs can be sequentially dropped from 40 feet to 20 feet of various flash memory μcs devices. New Flash memory μcs devices, but also need to provide flash memory for programming programming tools, such as AT89C2051 in the actual programming, its RST pin on the need for three levels of programming voltage: TTL logic 0, logic 1 And 12V pulse voltage. Figure circuit, with only two transistors and a small resistor, can provide AT8051μCS flash memory programming with three levels of voltage series. The circuit uses 12V power supply. Transistors Q1 and Q2 in the circuit use small-signal, high-speed NPN tubes. Resistors R1 and R2 are selected to be 1% fine, and the remaining resistors can be carbonized at 5%