What is Diode Transistor Logic (DTL) Circuit?

Diode Transistor Logic (DTL) is also a saturated logic and uses diodes, resistors and transis­tors. The circuit diagram is shown in Fig. 47.2. The ba­sic DTL logic circuit is the NAND gate.

Diode Transistor Logic (DTL) Circuit

When inputs to all the three diodes are high, neither diode conducts and the tran­sistor is turned on by the cur­rent provided by VCC through R1 and output is, therefore, low. If either or all inputs are low, the associat­ed diode will conduct, the transistor will turn off and output is, therefore, high. It is seen that output is low only when all the inputs are high.

The family is characterized by (i) limited operating speed, (ii) fan-in of 8, (iii) fan-out of 5, (iv) low power consumption (v) poor noise immunity and (vi) highly temperature sensitive to threshold voltage.

As already mentioned, this technology has also become obsolete now.

Related posts:

  1. What is Tristate Logic or Three State Logic Circuit?
  2. What is Transistor Transistor Logic (TTL) Circuit?
  3. What is Resistor Transistor Logic (RTL) Circuit?
  4. Diode Logic Circuits
  5. Logic Circuit in Static Relay
  6. What is Emitter Coupled Logic (ECL) Circuit?
  7. Integrated Injection Logic (IIL) Circuit
  8. Programmable Logic Array (PLA)
  9. Programmable Array Logic (PAL)
  10. Comparison of Logic Families
  11. Digital Logic Families Interview Questions and Answers
  12. Logic Circuits Interview Questions and Answers
  13. Logic Gates and Boolean Algebra Interview Questions and Answers
  14. How to use a Transistor as a Diode – Working and Equation
  15. Transistor Action : Operation of PNP Transistor
  16. Bridge Rectifier Circuit Diagram with freewheeling diode
  17. Tunnel Diode Equivalent Circuit
  18. AC Equivalent Circuit of Semiconductor Diode
  19. Two Diode Full Wave Rectifier Circuit
  20. Diode as a Circuit Element