COMPUTING

Chapter 7 Pulse Circuits and Waveform Generators– T 2 ⁄ ( R A|| R B )CR A – 2R= ln⎛---------------------- B ⎞ = ln( R⎝ 2R A – R B⎠A – 2R B )–ln( 2R A – R B )orT 2 ⁄ ( R A|| R B )C = ln( 2R A – R B ) – ln( R A – 2R B ) =RT A ⋅ R B 2R2-------------------CA – R= ⋅BR A + R ln ----------------------B⎝⎛ R A – 2R B⎠⎞ln 2R A – R---------------------- B⎝⎛ R A – 2R B⎠⎞(7.14)However, there is one restriction as we can see from relation (7.13), that is, the termR B ⁄ ( R A + R B ) must be less than 1⁄ 3. Therefore, the period T is the summation of (7.11) and(7.14) from which we obtain the relationT T 1 + T 2 0.69R A C R A ⋅ R B 2R-------------------CA – R= = + ⋅BR A + R ln ----------------------B⎝⎛ R A – 2R B⎠⎞RT 0.69R A ⋅ R B2RA + ------------------- CA – R=⋅ ⋅B+ln ----------------------⎝⎛ R A – 2R B⎠⎞R AR B(7.15)subject to the condition thatshown below.R B ⁄ ( R A + R B ) < 1 ⁄ 3, and this condition can be simplified asR BR A + R B------------------- < 1⁄33R B < R A + R B2R B