AT17 Series

7

AC Characteristics for AT17C256

V

Symbol

Description

Commercial

Industrial/Military

Units

Min

Max

Min

Max

T

OE

(2)

OE to Data Delay

25

25

ns

T

CE

(2)

CE to Data Delay

45

45

ns

T

CAC

(2)

CLK to Data Delay

50

55

ns

T

OH

(2)

Data Hold From CE, OE, or CLK

0

0

ns

T

DF

(3)

CE or OE to Data Float Delay

50

50

ns

T

LC

CLK Low Time

20

20

ns

T

HC

CLK High Time

20

20

ns

T

SCE

CE Setup Time to CLK (to guarantee proper counting)

35

40

ns

T

HCE

CE Hold Time to CLk (to guarantee proper counting)

0

0

ns

T

HOE

OE High Time (guarantees counter is reset)

20

20

ns

F

MAX

MAX Input Clock Frequency

12.5

12.5

MHz

AC Characteristics for AT17C256 When Cascading

V

Notes:

1. Preliminary specifications for military operating range only.

2. AC test load = 50 pf.

3. Float delays are measured with 5 pF AC loads. Transition is measured

±200 mV from steady state active levels.

Symbol

Description

Commercial

Industrial/Military

Units

Min

Max

Min

Max

T

CDF

(3)

CLK to Data Float Delay

50

50

ns

T

OCK

(2)

CLK to CEO Delay

35

40

ns

T

OCE

(2)

CE to CEO Delay

35

35

ns

T

OOE

(2)

RESET/OE to CEO Delay

30

35

ns