Datasheet

© 2009 Microchip Technology Inc. DS22153C-page 5
MCP9843/98243
SENSOR AND EEPROM SERIAL INTERFACE TIMING SPECIFICATIONS
Electrical Specifications: Unless otherwise indicated, GND = Ground, T
A
= -20°C to +125°C, and C
L
= 80 pF
(Note 1, 5).
V
DD
= 1.8V to 5.5V V
DD
= 2.2V to 5.5V
Parameters Sym Min Max
Min Max Units Conditions
2-Wire I
2
C Interface
Serial port frequency f
SCL
10 100 10 400 kHz Note 2, 4
Low Clock t
LOW
4700 — 1300 —nsNote 2
High Clock t
HIGH
4000 — 600 —nsNote 2
Rise time t
R
— 1000 20 300 ns
Fall time t
F
20 300 20 300 ns
Data in Setup time t
SU:DI
250 — 100 —nsNote 3
Data in Hold time t
HD:DI
0—0 —nsNote 6
Data out Hold time t
HD:DO
200 900 200 900 ns Note 4
Start Condition Setup time t
SU:STA
4700 — 600 —ns
Start Condition Hold time t
HD:STA
4000 — 600 —ns
Stop Condition Setup time t
SU:STO
4000 — 600 —ns
Bus idle t
B:FREE
4700 — 1300 —ns
Time out (Sensor Only) t
OUT
——25 35 ms V
DD
= 3.0V to 3.6V
Bus Capacitive load C
b
——— 400 pf
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:DAT
≥ 250 ns must
be met. This device does not stretch SCL Low time. It outputs the next data bit to the SDA line within
t
RMAX
+ t
SU:DI MIN
= 1000 ns + 250 ns = 1250 ns (according to the Standard-mode I
2
C-bus specification)
before the SCL line is released.
4: As a transmitter, the device provides internal minimum delay time t
HD:DAT MIN
to bridge the undefined
region (min. 300 ns) of the falling edge of SCL t
F MAX
to avoid unintended generation of Start or Stop
conditions.
5: For V
DD
ranges of 1.8V to the temperature sensor V
POR_TS
, the temperature sensor becomes partially
biased and consumes 100 µA (typical) until the sensor POR resets and acknowledges a shutdown com-
mand.
6: As a receiver, SDA should not be sampled at the falling edge of SCL. SDA can transition t
HD:DI
0ns after
SCL toggles Low.