3Simplified ECL Inverter Example: Select R so that Vo= -1.5V. Use IEE= 0.1mA.
4ECL with Resistor Biasing Example: Find R and R3 if VEE= VEE2=−5.2V, VL=−1.3V, IEE= 300μA and IEE2= 100μA.
5Example: Use the above circuit design an ECL gate for which VH=−1 Example: Use the above circuit design an ECL gate for which VH=−1.7V and VL=−2.3V . The average power dissipation should be less that 2mW. The supply voltage is −5.2V . Neglect the base currents.
7Figure Basic circuit of the ECL 10K logic-gate family tp≈1ns, the time it takes light to travel 1 foot.
8Practice Problem For previous circuit, find IE through RE if A and B are left open.Also find vC, QR and vCA,B.Use VR= -1.32V, VBE=0.75V and a very large β.
9Figure The proper way to connect high-speed logic gates such as ECL. Properly terminating the transmission line connecting the two gates eliminates the “ringing” that would otherwise corrupt the logic signals. (See Section )
10Figure 14.28 Simplified version of the ECL gate for the purpose of finding transfer characteristics.
11Practice ProblemsFind VOL and VOH (neglect iC of QR) if β=100. Then find NMH and NML if VIL and VIH are defined as the conditions for which IE, QR/IE, QA= 99 and vice-versa.
12Figure 14.30 Circuit for determining VOH VOH= -0.88V. Take into account base current and variations in vBE. Assume that at iC= 1mA, vBE= 0.75VFigure Circuit for determining VOH
13Figure 14.29 The OR Transfer Characteristic vOR vs vI, for the circuit in fig. 14.28
22For the ECL inverter shown in the following sketch, the high voltage level is VH = −1.7V and the average power dissipated when the input is high 50% of the time is P =5mW. Determine the source’s current IEE, the low voltage level VL, the reference voltage level VREF and the value of resistance R3
23Find VL, VH and VREF for the following circuit Find VL, VH and VREF for the following circuit. Neglect base currents and assume VBE=0.7V if a transistor is ON.