24LC21
TABLE 1-3:
AC CHARACTERISTICS
Standard Mode
Parameter
Symbol
Min
Clock frequency
F
CLK
Clock high time
T
HIGH
Clock low time
T
LOW
SDA and SCL rise time
T
R
SDA and SCL fall time
T
F
START condition hold time T
HD
:
STA
START condition setup
time
Data input hold time
Data input setup time
STOP condition setup time
Output valid from clock
Bus free time
T
SU
:
STA
T
HD
:
DAT
T
SU
:
DAT
T
SU
:
STO
T
AA
T
BUF
—
4000
4700
—
—
4000
4700
0
250
4000
—
4700
Max
100
—
—
1000
300
—
—
—
—
—
3500
—
Vcc= 4.5 - 5.5V
Fast Mode
Min
—
600
1300
—
—
600
600
0
100
600
—
1300
Max
400
—
—
300
300
—
—
—
—
—
900
—
kHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Units
Remarks
(Note 1)
(Note 1)
After this period the first clock
pulse is generated
Only relevant for repeated
START condition
(Note 2)
Output fall time from V
IH
T
OF
min to V
IL
max
Input filter spike suppres-
T
SP
sion (SDA and SCL pins)
Write cycle time
T
WR
Transmit-Only Mode Parameters
Output valid from VCLK
T
VAA
VCLK high time
T
VHIGH
VCLK low time
T
VLOW
Mode transition time
T
VHZ
Transmit-Only power up
T
VPU
time
Endurance
—
—
—
—
—
4000
4700
—
0
10M
250
50
10
2000
—
—
500
—
—
20 + .1
C
B
—
—
—
600
1300
—
0
10M
250
50
10
1000
—
—
500
—
—
ns
ns
ms
ns
ns
ns
ns
ns
cycles
(Note 2)
Time the bus must be free
before a new transmission
can start
(Note 1), C
B
≤
100 pF
(Note 3)
Byte or Page mode
25
°
C, Vcc = 5.0V, Block Mode
Note 1: Not 100% tested. C
B
= total capacitance of one bus line in pF.
2: As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region (min-
imum 300 ns) of the falling edge of SCL to avoid unintended generation of START or STOP conditions.
3: The combined T
SP
and V
HYS
specifications are due to new Schmitt trigger inputs which provide improved
noise and spike suppression. This eliminates the need for a T
I
specification for standard operation.
4: This parameter is not tested but guaranteed by characterization. For endurance estimates in a specific appli-
cation, please consult the Total Endurance Model which can be obtained on our BBS or website.
©
1996 Microchip Technology Inc.
DS21095F-page 3
MICROCHIP [ MICROCHIP TECHNOLOGY ]
