Loads capacitive

For the preceding expressions, the quartz resonator is not connected to an external driving network. The effect of the external network can be accounted for by a load capacitance Ci in parallel with Cq. In the presence of an external load capacitance Ci, the antiresonance frequency of the loaded quartz resonator is expressed as... 

Light loading results if the loading capacitance does not cancel all of the loop inductance. The loop inductance that is not canceled causes a decrease in load current and power output, and an increase in plate impedance. 

To relate 7c,sat to a gate response time tg, consider one MOSFET driving an identical MOSFET as load capacitance. Then the current from (Eq. 7.12) charges this capacitance to a voltage Vd in a gate response time Tg given by (Shoji, 1988)... 

An JV-stage output buffer is illustrated in Fig. 8.27. Higher drive capability results from employing transistors of increasing channel width. As the transistor width increases from stage to stage by a factor of /, so does the current drive capability and the input capacitance. If Cg is the input or gate capacitance of the first inverter in the buffer, then the second inverter has an input capacitance of fCg and the Nth inverter has an input capacitance of and a load capacitance of f Cc, which is equal to C, the... 

Thus, it has a propagation delay of ft. The second inverter in the buffer has an input capacitance of f Co and an accumulated delay of 2fr at its output. The Nth inverter has an input capacitance of / Cq, which is equal to the load capacitance at the output pin, and an accumulated propagation delay of Nfr, which is the overall delay of the buffer. 

Consider an example in which Cq = 50 f F and r = 0.5 ns for a typical gate driving an identical gate on the chip. Suppose this typical gate is to drive an output pin with load capacitance Ci = 55 pF, instead of an identical gate. If an output buffer is used... 

Load capacitance is 50 pF, load resistance 500 fJ, except ECL is driving 50-S2 transmission. 

Cioad = total equivalent load capacitance, Cp[Pg.746]

Cext = total parallel equivalent load capacitance Vdd = power supply voltage / = output operating frequency... 

Ohmic-capacitive loads mainly require reactive power and only a little active power. The voltage is usually controlled, and the resulting current is the product of the time derivative of the voltage and the load capacitance. 

Delay information is specified as each time difference between two events (logic-level changes) at the input and output pins. This time difference can be expressed as a linear function, although it is ordinarily the function of the load capacitance to be driven. Items (8)-(12) are the constraints to be satisfied. These can also be expressed in linear function. In other words, constraints are also specified in the time differences between two events. Constraint satisfaction is specified as a linear function greater than 0. 

Since the somce follower can only source current, an external current source, of sufficient strength, is required to discharge the parasitic load capacitance. This causes a slew on the falling edge that is optional to the current somce. The slew, and therefore the current somce, must be sufficient to provide time for the signal to settle at the next pixel value. 

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