TIBPLS506ACFN datasheet(11/16 Pages) TI1

11 / 16 page

TIBPLS506AC

× 97 × 8 FIELD-PROGRAMMABLE LOGIC SEQUENCER

SRPS003C – D3090, DECEMBER 1987 – REVISED NOVEMBER 1995

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

OR term loading

As shown in Figure 3 and by the fmax calculations, fmax is affected by the number of terms connected to each

OR array line. Theoretically, fmax is calculated as:

fmax =

tsu ) tpd CLK to Q

Since the setup time (input or feedback to S/R

↓) varies with the number of terms connected to each OR array

line, (due to capacitance loading) fmaxwill also vary. Figure 3 illustrates the relationship between the number of

terms connected per OR line and the setup time.

Use Figure 3 to determine the worst-case setup time for a particular application. Identify the OR array line with

the maximum number of terms connected. Count the number of terms and use the graph to determine the setup

time.

020

Maximum Number of OR Terms Connected

WORST-CASE SETUP TIME

(input or feedback to SR

↓)

”OR” TERM LOAD

100

VCC = 4.75 V

TA = 75°C

Figure 3

TIBPLS506ACFN Datasheet(PDF) 11 Page - Texas Instruments