MAX6646YMUA+T Maxim Integrated Products, MAX6646YMUA+T Datasheet - Page 7

• Manufacturer Part Number: MAX6646YMUA+T
• Description: IC SENSOR REMOTE SMBUS 8UMAX
• Manufacturer: Maxim Integrated Products

Specifications of MAX6646YMUA+T

• Function: Temp Monitoring System (Sensor)
• Topology: ADC, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -55°C ~ 125°C, External Sensor
• Output Type: I²C™/SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -55°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Full Temp Accuracy: +/- 3 C, +/- 3.2 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Digital Output - Number Of Bits: 11 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

To ensure valid extended data, read extended resolu-
tion temperature data using one of the following
approaches:
1) Put the MAX6646/MAX6647/MAX6649 into standby
Figure 1. SMBus Protocols
Figure 2. SMBus Write Timing Diagram
Write Byte Format
mode by setting bit 6 of the configuration register to 1.
Initiate a one-shot conversion using command byte
0Fh. When this conversion is complete, read the con-
tents of the temperature data registers.
Read Byte Format
Send Byte Format
S = Start condition
P = Stop condition
S
S
S
Slave Address: equiva-
lent to chip-select line
ADDRESS
ADDRESS
+145°C Precision SMBus-Compatible Remote/
Slave Address: equiva-
lent to chip-select line of
a 3-wire interface
SMBCLK
SMBDATA
7 bits
Local Sensors with Overtemperature Alarms
7 bits
ADDRESS
7 bits
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
t
_______________________________________________________________________________________
SU:STA
A
WR
t
HD:STA
WR
Shaded = Slave transmission
/// = Not acknowledged
t
LOW
ACK
WR
B
ACK
t
HIGH
Command Byte: sends com-
mand with no data, usually
used for one-shot command
COMMAND
Command Byte: selects
which register you are
reading from
COMMAND
8 bits
t
SU:DAT
ACK
C
8 bits
E = SLAVE PULLS SMBDATA LINE LOW
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE
H = LSB OF DATA CLOCKED INTO SLAVE
Command Byte: selects which
register you are writing to
ACK
D
ACK
COMMAND
8 bits
E
P
F
S
2) If the MAX6646/MAX6647/MAX6649 is in run mode,
Receive Byte Format
S
Slave Address: repeated
due to change in data-
flow direction
G
read the status byte. If the BUSY bit indicates that a
conversion is in progress, wait until the conversion is
complete (BUSY bit set to zero) before reading the
temperature data. Following a conversion comple-
tion, immediately read the contents of the tempera-
ture data registers. If no conversion is in progress,
the data can be read within a few microseconds,
which is a sufficiently short period of time to ensure
that a new conversion cannot be completed until
after the data has been read.
ADDRESS
7 bits
ADDRESS
ACK
7 bits
I = MASTER PULLS DATA LINE LOW
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
M = NEW START CONDITION
H
Data Byte: data goes into the register
set by the command byte (to set
thresholds, configuration masks, and
sampling rate)
RD
DATA
8 bits
RD
I
ACK
J
ACK
Data Byte: reads data from
the register commanded
by the last Read Byte or
Write Byte transmission;
also used for SMBus Alert
Response return address
K
Data Byte: reads from
the register set by the
command byte
DATA
8 bits
DATA
8 bits
t
ACK
SU:STO
L
t
BUF
M
///
///
P
1
P
P
7