Integrated injection logic
The integrated injection logic , abbreviated IIL , I 2 L , or I2L ( English integrated injection logic , also referred to by the developers as merged transistor logic , MTL ) is a circuit technology for logic gates in electronics with two active components per switching stage Bipolar transistors are used. I2L was developed in 1971 by Siegfried K. Wiedmann and Horst H. Berger and has transit times comparable to the previously available transistor-transistor logic (TTL) , but it requires significantly less current and is less sensitive to interference.
The IIL circuit technology was the last logic family implemented with bipolar transistors and was important for the then complex digital integrated circuits ( VLSI ) such as the Texas Instruments SBP0400 until the 1980s . It was virtually complete by the still dominant in digital integrated circuits and field effect transistors based CMOS replaced circuit technology. Due to the low operating voltage of 1 V and the comparatively low power loss compared to TTL, IIL circuits are also suitable for mobile battery operation. Among other things, the first digital wristwatches in the mid-1970s, such as the Sinclair Radionics Black Watch , were made using IIL circuit technology.
function
The logic levels are at IIL for logic- 1 at greater than 0.7 V and for logic- 0 at less than 0.2 V, the supply voltage of an IIL gate is consistent 1 V. The control of the individual stages is effected gate current-controlled, whereby an over TTL results in higher interference immunity.
Each IIL switching stage, as marked in the blue framed area in the circuit diagram on the right, is in principle a logic inverter , consisting of two bipolar transistors: one NPN and one PNP transistor. The NPN transistor is the switching transistor, while the PNP transistor in combination with a resistor serves as a current source for the base current of the NPN transistor. A logical 0 at the input of the stage results from a connection of the input to the reference potential (ground), which means that the current of the PNP transistor flows through the input, which blocks the NPN switching transistor. A logical 1 at the input of the stage corresponds to an open input, in this case the current of the PNP transistor flows through the NPN switching transistor and this opens.
Logical functions, in addition to the inverter function of the IIL unit cell, can be created in terms of circuitry using wired AND and wired OR . In the adjacent circuit diagram, the circuitry Wired-AND linkage is converted into a logical OR gate by inverting the two inputs and the output twice according to De Morgan's laws . In more complex IIL circuits, the switching transistors are also designed as so-called multi-collector transistors, that is, bipolar transistors with several parallel collector connections. These are used in parallel switching stages to create logical links and thus enable complex digital circuits to be set up.
literature
- Arijit Saha, Nilotpal Manna: Digital Principles & Logic Design . Jones & Bartlett Publishers, 2009, ISBN 978-0-7637-7373-1 .
Individual evidence
- ↑ K. Hart, Arie Slob: Integrated Injection Logic: A New Approach to LSI . In: IEEE Journal of Solid-State Circuits . 7, No. 5, 1972, pp. 346-351. doi : 10.1109 / JSSC.1972.1052891 .
- ^ Siegfried K. Wiedmann, Horst H. Berger: Merged-transistor logic (MTL) -a low-cost bipolar logic concept . In: IEEE Journal of Solid-State Circuits . 7, No. 5, 1972, pp. 340-346. doi : 10.1109 / JSSC.1972.1052890 .
- ↑ 1999 Computer Entrepreneur Award Recipient Sir Clive Sinclair. (No longer available online.) IEEE Computer Society Awards, archived from the original on April 20, 2014 ; accessed on March 29, 2014 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
