© 2009 Microchip Technology Inc.

DS22144A-page 3

25LC640A

TABLE 1-2:

AC CHARACTERISTICS

AC CHARACTERISTICS

Extended (M):

Param.

No.

Sym.

Characteristic

Min.

Max.

Units

Test Conditions

Clock frequency

—

—

10

5

MHz

MHz

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

CS setup time

50

100

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

CS hold time

100

200

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

CS disable time

50

—

ns

—

5

Tsu

Data setup time

10

20

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

Data hold time

20

40

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

CLK rise time

—

100

ns

(Note 1)

CLK fall time

—

100

ns

(Note 1)

Clock high time

50

100

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

10

Clock low time

50

100

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

11

Clock delay time

50

—

ns

—

12

Clock enable time

50

—

ns

—

13

Output valid from clock

low

—

—

50

100

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

14

Output hold time

0

—

ns

(Note 1)

15

Output disable time

—

—

40

80

ns

ns

4.5V

≤ Vcc ≤ 5.5V(Note 1)

2.5V

≤ Vcc ≤ 4.5V(Note 1)

16

HOLD setup time

20

40

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

17

HOLD hold time

20

40

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

18

HOLD low to output

High-Z

30

60

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V(Note 1)

2.5V

≤ Vcc < 4.5V(Note 1)

19

HOLD high to output valid

30

60

—

—

ns

ns

4.5V

≤ Vcc ≤ 5.5V

2.5V

≤ Vcc < 4.5V

20

Internal write cycle time

—

5

ms

(NOTE 3)

21

—

Endurance

1M

—

E/W

Cycles

(NOTE 2)

Note 1: This parameter is periodically sampled and not 100% tested.

2: This parameter is not tested but ensured by characterization. For endurance estimates in a specific

application, please consult the Total Endurance™ Model which can be obtained from Microchip’s web site

at www.microchip.com.

is complete.