HD74AC datasheet(14/52 Pages) HITACHI

14 / 52 page

FACT Descriptions and Family Characteristics

2.2 Capacitive Loading Effects

In addition to temperature and power supply effects, capacitive loading effects for loads greater than 50 pF

should be taken into account for propagation delays of FACT devices. Minimum delay numbers may be

determined from table 3. Propagation delays are measured to the 50% point of the output waveform.

Table 3 Minimum Propagation Delay

Voltage(V)

Parameter

3.0

4.5

5.5

Units

rise

ps/pF

fall

12.5

ps/pF

Note:

TA = 25˚C

The two graphs following, figures 11 and 12, describe propagation delays on FACT devices as affected by

variations in power supply voltage (V

CC) and lumped load capacitance (CL). Figures 13 and 14 show the

effects of lumped load capacitance on rise and fall times for FACT devices.

Delay (ns)

VCC (Volts)

3.0

3.5

4.0

4.5

5.0

5.5

6.0

L = 1000

pF,

PLH

L =

1000

pF, t

PHL

L =

470 pF,

PLH

L = 470 pF, t

PHL

L = 220

pF, t

PLH

CL = 50 pF, tPHL

CL = 50 pF, tPLH

CL = 220 pF, t

PHL

Figure 11 Propagation Delay vs. V

CC (HD74AC00)

HD74AC Datasheet(PDF) 14 Page - Hitachi Semiconductor

HD74AC Datasheet(HTML) 14 Page - Hitachi Semiconductor

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

Datasheet Download

Link URL