MAX6641AUB90+ Maxim Integrated Products, MAX6641AUB90+ Datasheet - Page 8

• Manufacturer Part Number: MAX6641AUB90+
• Description: IC TEMP MONITOR SMBUS 10UMAX
• Manufacturer: Maxim Integrated Products

Specifications of MAX6641AUB90+

• Function: Fan Control, Temp Monitor
• Topology: ADC, PWM Generator, Tach Counter
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: I²C™/SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Full Temp Accuracy: +/- 4 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Digital Output - Number Of Bits: 8 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Figure 1. SMBus Protocols
Figure 2. SMBus Write Timing Diagram
8
Write Byte Format
Read Byte Format
Send Byte Format
S = Start condition
P = Stop condition
SMBCLK
SMBDATA
S
S
_______________________________________________________________________________________
S
ADDRESS
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
Slave address: equivalent
to chip-select line
ADDRESS
7 bits
t
SU:STA
Slave address: equiva-
lent to chip-select line of
a 3-wire interface
7 bits
ADDRESS
A
7 bits
t
HD:STA
WR
t
LOW
WR
Shaded = Slave transmission
/// = Not acknowledged
B
t
HIGH
ACK
ACK
WR
Command byte: sends com-
mand with no data, usually
used for one-shot command
COMMAND
t
SU:DAT
Command byte: selects
from which register you
are reading
8 bits
COMMAND
C
8 bits
ACK
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
ACK
D
Command byte: selects to
which register you are writing
ACK
COMMAND
E
P
8 bits
F
S
Receive Byte Format
S
Slave address: repeated
due to change in data-
flow direction
ADDRESS
G
7 bits
ADDRESS
ACK
7 bits
Data byte: data goes into the register
set by the command byte (to set
thresholds, configuration masks, and
sampling rate)
I = MASTER PULLS DATA LINE LOW
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
M = NEW START CONDITION
RD
H
DATA
RD
8 bits
ACK
ACK
I
J
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
Data byte: reads from
the register set by the
command byte
DATA
K
8 bits
DATA
8 bits
ACK
t
SU:STO
///
///
L
t
BUF
P
1
M
P
P