© 2008 Microchip Technology Inc.

DS21160G-page 3

24LC21A

TABLE 1-2:

AC CHARACTERISTICS

Parameter

Symbol

Vcc = 2.5-5.5V

Standard Mode

Vcc = 4.5 - 5.5V

Fast Mode

Units

Remarks

Min.

Max.

Min.

Max.

Clock frequency

—100

—

400

kHz

Clock high time

4000

—

600

—

ns

Clock low time

4700

—

1300

—

ns

SDA and SCL rise time

—

1000

—

300

ns

(Note 1)

SDA and SCL fall time

—

300

—

300

ns

(Note 1)

Start condition hold time

4000

—

600

—

ns

After this period the first clock

pulse is generated

Start condition setup time

4700

—

600

—

ns

Only relevant for repeated

Start condition

Data input hold time

0—

0

—

ns

(Note 2)

Data input setup time

250

—

100

—

ns

Stop condition setup time

4000

—

600

—

ns

Output valid from clock

—

3500

—

900

ns

(Note 2)

Bus free time

4700

—

1300

—

ns

Time the bus must be free

before a new transmission

can start

—

250

20 + 0.1

250

ns

≤ 100 pF

Input filter spike suppres-

sion (SDA and SCL pins)

—50

—

50

ns

(Note 3)

Write cycle time

—

10

—

10

ms

Byte or Page mode

Transmit-Only Mode Parameters

Output valid from VCLK

—

2000

—

1000

ns

VCLK high time

4000

—

600

—

ns

VCLK low time

4700

—

1300

—

ns

VCLK setup time

0—

0

—

ns

VCLK hold time

4000

—

600

—

ns

Mode transition time

—

1000

—

500

ns

Transmit-only power-up

time

0—

0

—

ns

Input filter spike suppres-

sion (VCLK pin)

—

100

—

100

ns

Endurance

—

1M

—

1M

—

cycles

25°C, Vcc = 5.0V, Block

mode (Note 4)

Note 1:

2:

As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region

(minimum 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions.

3:

4:

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.