![]() Circuit of standard 3-input TTL NAND Gate With Q 2 turned ON, transistor Q 4 will also be turned ON.īoth the transistors at the output side will conduct and so the output at terminal will have LOW value, which is considered as logic 0. The diode D C at the collector-base junction is forward biased. ![]() When both the inputs A and B are high, both the diodes at the emitter-base junction will be reverse biased. The same operation will take place as explained above. When any one input, either A or B is low, the diode with low input will be forward biased. Since Q 3 is an emitter follower, the output at the terminal will also be HIGH, which is at logic 1. With Q 2 open, the transistor Q 4 will also cut off. The supply voltage gets dropped in the resistor R 1 and it will not be sufficient to turn ON the transistor Q 2. So the current due to the supply voltage +V CC = 5 V will go to the ground through R 1 and the two diodes D A and D B. When both inputs A and B are low, both the diodes are forward biased. Diode D C represents the collector-base junction of transistor Q 2. (2) Special circuits in Circuit layout andsystem design are required.In the figure, diodes, D A and D B represent the 2-input emitter junction of transistor Q 1. Disadvantages : (1) Wired output capability is possible only with tristate andopen collector types. Totem pole outputs cannot be connected togetherbecause such a connection might produce excessive currentand may result in damage to the devices. Why totem pole outputs Cannot be connected together? The purpose is to maximize the output voltage, very nearly equalto the supply voltage. Author has 2.5k answers and 3.3m answer views.Manjunath Pai H, former 30+ yrs in Electronics Engg and loved it. ![]() Similarly one may ask, what is the purpose of a totem pole in electronics?ģ Answers. Subsequently, one may also ask, what is totem pole driver?Ī totem pole driver or output stage is a looseterm used to mean that the output is driven actively in both thehigh and low directions.Īlso, what is a totem pole in a standard TTL circuit? The TTL " totem- pole" outputstructure often has a momentary overlap when both the upper andlower transistors are conducting, resulting in a substantial pulseof current drawn from the power supply. The output of highlevel is 10 V max, low level is 0.5 V min. The Highand Low level of the output are determined. Totem- pole output, also known as apush-pull output, is a type of electronic circuit andusually realized as a complementary pair of transistors. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
January 2023
Categories |