At the output of all gates there is a capacitive load (CL) caused by the input capacitance of the next stage. This could be a printed circuit board interconnect or quite simply an oscilloscope lead....

Diode transistor logicThe DTL or diode transistor logic first became available commercially in 1962. The circuit diagram for a two-input DTL NAND gate is shown in Fig. 9.2(a) and although it is no lon...

The bipolar junction transistor or BJT as it is more commonly known can be considered in digital terms as a simple single-pole switch. It physically consists of three layers of semiconductor (which ca...

Now we shall design a D-type based circuit that will count up or down, under the control of a single external input, through the first five prime numbers (in binary). We must ensure that the circuit w...

The general form of a synchronous sequential circuit is shown in Fig. 8.1. To recap, this has: external inputs, A, and outputs, Z; a combinational block can be considered in two parts; and 'memory’ in...

Synchronous binary counters are arguably the simplest sequential synchronous circuits. They use the flip-flops to store the circuit's count state and (usually) have no external inputs. Thus the next s...

A mod-W (or divide-by-N) asynchronous counter, where N=T, will count up to (N- 1) (an output of all 1’s) before resetting to all 0*s and beginning the count sequence again....

The output of a T-type flip-flop with T=) will simply toggle every time it is docked. So the circuit in Fig. 7.1 constructed from negative edge triggered T-type flip-flops will give the waveforms show...