VOLTAGE REGULATOR IC 723

EDLC Important topics

1. AC/DC analysis of BJT and FET ampliifier
2. OP-AMP inverting and non inverting amplifier, comparators, integrator, differentiator etc..
3. ADC/DAC (Flash, counter, Successive approximation)
4. Voltage regulator IC 723
5. IC 555 (block diagram, Astable, Monostable mode)

Functional Block Diagram of IC 555

Internal Schematic of IC 555

Here is the functional block digram of IC 555.

Astable multivibrator using IC 555

This circuit diagram shows how a 555 timer IC is configured to function as an astable multivibrator. An astable multivibrator is a timing circuit whose 'low' and 'high' states are both unstable. As such, the output of an astable multivibrator toggles between 'low' and 'high' continuously, in effect generating a train of pulses. This circuit is therefore also known as a 'pulse generator' circuit.



In this circuit, capacitor C1 charges through R1 and R2, eventually building up enough voltage to trigger an internal comparator to toggle the output flip-flop. Once toggled, the flip-flop discharges C1 through R2 into pin 7, which is the discharge pin. When C1's voltage becomes low enough, another internal comparator is triggered to toggle the output flip-flop. This once again allows C1 to charge up through R1 and R2 and the cycle starts all over again.



C1's charge-up time t1 is given by: t1 = 0.693(R1+R2)C1. C1's discharge time t2 is given by: t2 = 0.693(R2)C1. Thus, the total period of one cycle is t1+t2 = 0.693 C1(R1+2R2). The frequency f of the output wave is the reciprocal of this period, and is therefore given by: f = 1.44/(C1(R1+2R2)), wherein f is in Hz if R1 and R2 are in megaohms and C1 is in microfarads.

Electronic Devices And Linear Circuits

Hello All.. Visit following link for BJT, FETs and OP-AMP basics.. Design issues are also discussed nicely..
http://www.educypedia.be/electronics/analogmisac.htm