Modeling, Analysis, and Experimental Validation of Frequency Dividers with Direct Injection

Figure 6

(a) Nonlinear characteristics of the injection circuit shown in Figure 3(b) for different values of the constant injection voltage 𝑣_in=𝑉_inDC, obtained for 𝑉_DD=5V and 𝑉₀=1V. Measurements are obtained using integrated circuits ST HCF4007UB and the testing circuit in Figure 4. Approximate model for 𝑣_in=0 is obtained using cubic polynomial (4) with 𝑎_in=0.13mA/V, 𝑏_in=40uA/V², and 𝑐_in=35uA/V³. (b) Voltage-dependent transconductance 𝑔(𝑣). Measurement’s curve is obtained using (2) and curves shown in (a). Approximate model is obtained using the last term in (4) with 𝑘=−0.6mA/V².

(a)

(b)