Diode-transistor logic
In electronics , DTL is the abbreviation for the “ Diode Transistor Logic ” family of logic .
This technology of digital electronic circuits was developed in the early 1960s as the successor to resistance-transistor logic (RTL).
Logic gates and logic functions were implemented by linking diodes in the input area and then amplifying the logic signal using transistors . Compared to the RTL, this results in a higher processing speed and lower power consumption.
Layout and function
The adjacent circuit shows the structure of a NAND gate using DTL technology. When the input diodes V 1 and V 2 block (inputs at high potential), the current flows through the resistor R 2 , which forms a voltage divider with the resistor R 1 . The voltage on the base of transistor V 5 , increased in this way, leads to the transistor being turned on. This causes the output to go low. In positive logic , this corresponds to a NAND gate. Since the transistor goes into saturation , a long gate delay is obtained due to the need to clear the junction . DTL circuits are therefore no longer used. The logic levels of this circuit were typically around 0 to 1 V for the LOW level and around 1.7 V to 5 V for the HIGH level.
New logic families
The DTL family has practically no meaning in circuit development today and has been replaced by newer logic families.
The transistor-transistor logic (TTL) with its various subfamilies can be viewed as a direct further development of the diode-transistor logic . The slow fail-safe logic (LSL) was developed for use in environments with particularly strong electrical interference . The emitter-coupled logic (ECL) is also available for fast applications. These three technologies are all based on bipolar transistors .
In addition, the complementary MOS logic (CMOS logic) is available as a new logic family in CMOS technology through the use of field effect transistors .