Transconductance variation is straightforwardly implemented as a function of

bias current ratios, and sufficient OTA linearity is achieved by applying a combination of techniques: bulk input, parallel differential pairs and feedback.

In this case, the

bias current will be injected varying from 0.01 to 0.5 mA which significantly will alter the process parameters of the circuit.

When the corresponding model parameters in (11) are substituted with actual values from the model card, the relationship of the minimum supply voltage [V.sub.DD,min,two-level] and the

bias current IB can be got, as shown in Figure 6.

Exclusive Truevolt technology reduces extraneous factors such as noise, injected current, and input

bias current for increased measurement confidence.

Signal currents are usually less than 3000 nA full scale, so the I-to-V converter requires low input

bias current. A low-pass filter with a cutoff of 80 Hz to 100 Hz is desirable to remove extraneous noise.

In general, a PIN diode's RF resistance is controlled by adjusting the

bias current, since it is known that a PIN diode works as a current-controlled device.

The circuits require the addition of resistors to provide a

bias current return.

In post-layout simulations of the 2nd-order band-pass class 1 FAF the centre frequency is varied for [f.sub.0A] [congruent to] {18.2; 16.6; 15.85} MHz for

bias current [I.sub.A] = {65; 85; 95} [micro]A, respectively, and simulated magnitude responses are shown Fig.

However, control of DC

bias current in the structure of current conveyor (allowing [R.sub.x] or gm control typically) causes undesired influences of output resistance which damages stop band attenuation due to their effect in high-impedance nodes of filtering structure [35].

The opto-isolator feedback circuitry, if used, can require up to 1 mA of

bias current from the output to operate correctly.

where [g.sub.mi] = [square root of [K.sub.n] (p)[I.sub.B] (i = 1,2,3,4) and [K.sub.n(p)] is the transconductance parameter of NMOS (PMOS) transistor, and IB is an external DC

bias current of this element, respectively.