Extract IC PIC16LF506 Code from its flash and eeprom memory, disable the security fuse bit by focus ion beam technique after reverse engineering microcontroller circuitry pattern and scheme;
Figure 8-5 shows a series resonant oscillator circuit. This circuit is also designed to use the fundamental frequency of the crystal. The inverter performs a 180-degree phase shift in a series resonant oscillator circuit.
The 330 Ω resistors provide the negative feedback to bias the inverters in their linear region. For timing insensitive applications, the RC device option offers additional cost savings.
The RC oscillator frequency is a function of the supply voltage, the resistor (Rext) and capacitor (Cext) values, and the operating temperature. In addition to this, the oscillator frequency will vary from unit to unit due to normal process parameter variation before remove IC Extraction protection.
Furthermore, the difference in lead frame capacitance between package types will also affect the oscillation frequency, especially for low Cext values. The user also needs to take into account variation due to tolerance of external R and C components used.
Figure 8-6 shows how the R/C combination is connected to the PIC12C5XX. For Rext values below 2.2 kΩ, the oscillator operation may become unstable, or stop completely when Extract IC atmega168 code.
For very high Rext values (e.g., 1 MΩ) the oscillator becomes sensitive to noise, humidity and leakage. Thus, we recommend keeping Rext between 3 kΩ and 100 kΩ.
Although the oscillator will operate with no external capacitor (Cext = 0 pF), we recommend using values above 20 pF for noise and stability reasons before Extract chip atmega88p program.
With no or small external capacitance, the oscillation frequency can vary dramatically due to changes in external capacitances, such as PCB trace capacitance or package lead frame capacitance.
The Electrical Specifications sections show RC frequency variation from part to part due to normal process variation. The variation is larger for larger R (since leakage current variation will affect RC frequency more for large R) and for smaller C (since variation of input capacitance will affect RC frequency more).
Also, see the Electrical Specifications sections for variation of oscillator frequency due to VDD for given Rext/Cext values as well as frequency variation due to operating temperature for given R, C, and VDD values.
