This circuit is allows a digital pulse input to be divided by any number from 1 to 100 with control provided by a single knob. The function of this circuit is ideal for bench type work where the rapid set-up and flexibility of the division ratio is highly desirable. When the circuit input is low, Q1 and Q3 are off and Q2 is on. This is the figure of the circuit.
When the input goes high Q2 goes off and Q1 turns on Q3. This causes Q3 to displace the 100 pF capacitor's charge into A1's summing junction. A1's output responds by jumping to the required value to maintain the summing junction at 0V. This sequence is repeated for every input pulse. During this time A1's output will form the staircase shape. When A1's output is great enough to just bias C1's ``a'' input below ground, C1's output goes low and resets A1 to 0V. [Circuit’s source: National Semiconductor Notes].
When the input goes high Q2 goes off and Q1 turns on Q3. This causes Q3 to displace the 100 pF capacitor's charge into A1's summing junction. A1's output responds by jumping to the required value to maintain the summing junction at 0V. This sequence is repeated for every input pulse. During this time A1's output will form the staircase shape. When A1's output is great enough to just bias C1's ``a'' input below ground, C1's output goes low and resets A1 to 0V. [Circuit’s source: National Semiconductor Notes].
0 comments:
Post a Comment