Datasheet

© 2011 Microchip Technology Inc. DS25095A-page 5
MCP9808
TIMING DIAGRAM
SENSOR SERIAL INTERFACE TIMING SPECIFICATIONS
Electrical Specifications: Unless otherwise indicated, V
DD
= 2.7V to 5.5V, T
A
= -40°C to +125°C, GND = Ground
and C
L
= 80 pF. (Note 1)
Parameters Sym Min Max Units Conditions
2-Wire SMBus/Standard Mode I
2
C™ Compatible Interface (Note 1)
Serial Port Clock Frequency f
SC
0400kHz(Note 2, 4)
Low Clock t
LOW
1300 — ns (Note 2)
High Clock t
HIGH
600 — ns (Note 2)
Rise Time t
R
20 300 ns
Fall Time t
F
20 300 ns
Data in Setup Time t
SU-DI
100 — ns (Note 3)
Data In Hold Time t
HD-DI
0—ns(Note 5)
Data Out Hold Time t
HD-DO
200 900 ns (Note 4)
Start Condition Setup Time t
SU-START
600 — ns
Start Condition Hold Time t
HD-START
600 — ns
Stop Condition Setup Time t
SU-STOP
600 — ns
Bus Free t
B-FREE
1300 — ns
Time-out t
OUT
25 35 ms
Bus Capacitive Load C
b
—400pf
Note 1: All values referred to V
IL MAX
and V
IH MIN
levels.
2: If t
LOW
> t
OUT
or t
HIGH
> t
OUT
, the temperature sensor I
2
C interface will time-out. A Repeat Start command
is required for communication.
3: This device can be used in a Standard mode I
2
C bus system, but the requirement, t
SU-DI
≥ 100 ns, must
be met. This device does not stretch the SCL Low time.
4: As a transmitter, the device provides internal minimum delay time, t
HD-DO MIN
, to bridge the undefined
region (min. 200 ns) of the falling edge of SCL, t
F MAX
, to avoid unintended generation of Start or Stop
conditions.
5: As a receiver, SDA should not be sampled at the falling edge of SCL. SDA can transition t
HD-DI
0 ns after
SCL toggles Low.
t
SU-START
t
HD-START
t
SU-DI
t
SU-STOP
t
B-FREE
SCL
SDA
t
HD-DI/
t
HD-DO
t
HIGH
t
LOW
t
OUT
t
R
, t
F
START Condition
Data Transmission
STOP Condition