The variation of absolute data-to-output delays [T.sub.DQ,min] with FF
input capacitance ([C.sub.in]) for 16X (19.92 fF) capacitive load is illustrated in Figure 14.
The measured frequency was 1.06 MHz, the
input capacitance [C.sub.in] = 6 pF, the power dissipation capacitance [C.sub.pd] = 12 pF and the load capacitance was 47 pF, except the equivalent capacitance of the frequency measurement node, which has approximately 51 pF.
Unlike a typical 10:1 high-impedance scope probe with a 10-pf
input capacitance, a transmission-line probe's much smaller capacitance doesn't begin to degrade input impedance until very high frequencies are reached.
The gate
input capacitance [C.sub.iss] (when bulk shorts to source) does not originate solely from the gate-source capacitance [C.sub.gs] (and the gate-drain capacitance [C.sub.gd]).
Assuming the transistor model shown previously, the energy required to charge the
input capacitance [C.sub.GS] from the threshold voltage [V.sub.TH] ([V.sub.TH] = 0 for this model) up to the minimum input voltage for device switching [V.sub.SW] is
This calculation begins by determining the ratio between detector capacitance [C.sub.D] and transistor
input capacitance [C.sub.in] that results in minimum noise.
Their high DC input impedance of 1 MQ and the low
input capacitance (0.6 pF) ensure that the load on the DUT's operating point remains low.
Here, a transistor with a small
input capacitance is required.
The proposed memcapacitor emulator is designed in the way of composing the
input capacitance as a function of applied voltage.