voltage frequency synthesizer PLL


Posted on Aug 4, 2012

The µA2240 consists of four basic circuit elements: (1) a time-base oscillator, (2) an eight-bit counter, (3) a control flip-flop, and (4) a voltage regulator. The basic frequency of the time-base oscillator (TBO) is set by the external time constant determined by the values of R1 and Cl (1R1C1 = 2 kHz). The open-collector output of the TBO is connected to the regulator output via a 20 k ohm pull-up resistor, and drives the input to the eight-bit counter. At power-up, a positive trigger pulse is detected across C2 which starts the TBO and sets all counter outputs to a low state.


voltage frequency synthesizer PLL
Click here to download the full size of the above Circuit.

Once the µ2240 is initially triggered, any further trigger inputs are ignored until it is reset. In this astable operation, the µ2240 will free-run from the time it is triggered until it receives an external reset signal. Up to 255 discrete frequencies can be synthesized by connecting different counter outputs.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

PlayPIC Tutorial
Principle Power Amplifier Design
TENS Circuits
the designs of three phases SPWM variable frequency power supply of DSP
infrared detector circuit using pid20
12v to 120v voltage inverter circuit
amplifier timer
Commodore 64 I/O ROM Expansion Port
Components Voltage Tester Circuit Schematic
Telephone interfacing circuits
Infra Red Remote Control
The 555 Monostable



Top