MAX44000GDT+T Maxim Integrated Products, MAX44000GDT+T Datasheet - Page 19

• Manufacturer Part Number: MAX44000GDT+T
• Description: Optical Sensors - Industrial Digital Ambient Ligh t Sensor and Proximi
• Manufacturer: Maxim Integrated Products

Specifications of MAX44000GDT+T

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

One data bit is transferred during each SCL cycle. The
data on SDA must remain stable during the high period
of the SCL pulse. Changes in SDA while SCL is high are
control signals. See the START and STOP Conditions sec-
tion. SDA and SCL idle high when the I
SDA and SCL idle high when the bus is not in use. A
master initiates communication by issuing a START con-
dition. A START condition is a high-to-low transition on
SDA with SCL high. A STOP condition is a low-to-high
transition on SDA while SCL is high (Figure 5). A START
condition from the master signals the beginning of a
transmission to the IC. The master terminates transmis-
sion, and frees the bus by issuing a STOP condition. The
bus remains active if a Repeated START condition is
generated instead of a STOP condition.
The IC recognizes a STOP condition at any point during
data transmission except if the STOP condition occurs in
Figure 5. START, STOP, and Repeated START Conditions
Figure 4. 2-Wire Interface Timing Diagram
SDA
SCL
SDA
SCL
t
HD,STA
S
CONDITION
START
______________________________________________________________________________________
START and STOP Conditions
Ambient and Infrared Proximity Sensor
t
LOW
Early STOP Conditions
t
R
Sr
t
t
SU,DAT
HIGH
t
F
2
C bus is not busy.
Bit Transfer
t
HD,DAT
P
t
SU,STA
START CONDITION
the same high pulse as a START condition. For proper
operation, do not send a STOP condition during the
same SCL high pulse as the START condition.
The acknowledge bit (ACK) is a clocked 9th bit that the
IC uses to handshake receipt of each byte of data when
in write mode (Figure 6). The IC pulls down SDA dur-
ing the entire master-generated ninth clock pulse if the
previous byte is successfully received. Monitoring ACK
allows for detection of unsuccessful data transfers. An
unsuccessful data transfer occurs if a receiving device
is busy or if a system fault has occurred. In the event of
an unsuccessful data transfer, the bus master can retry
communication. The master pulls down SDA during the
ninth clock cycle to acknowledge receipt of data when
the IC is in read mode. An acknowledge is sent by the
master after each read byte to allow data transfer to
continue. A not acknowledge is sent when the master
reads the final byte of data from the IC, followed by a
STOP condition.
Figure 6. Acknowledge
REPEATED
SCL
SDA
CONDITION
START
t
HD,STA
1
2
t
SP
t
SU,STO
NOT ACKNOWLEDGE
ACKNOWLEDGE
CONDITION
STOP
ACKNOWLEDGMENT
8
CLOCK PULSE FOR
Acknowledge
t
BUF
CONDITION
9
START
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