MAX6694TE9A+T Maxim Integrated Products, MAX6694TE9A+T Datasheet - Page 8

• Manufacturer Part Number: MAX6694TE9A+T
• Description: IC TEMP MONITOR 5CH 16TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX6694TE9A+T

• Function: Temp Monitoring System (Sensor)
• Topology: ADC, Buffer, Multiplexer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

5-Channel Precision Temperature Monitor
with Beta Compensation
350µA. During either software or hardware standby,
data is retained in memory. During hardware standby,
the SMBus interface is inactive. During software stand-
by, the SMBus interface is active and listening for
SMBus commands. The timeout is enabled if a start
condition is recognized on SMBus. Activity on the
SMBus causes the supply current to increase. If a
standby command is received while a conversion is in
progress, the conversion cycle is interrupted, and the
temperature registers are not updated. The previous
data is not changed and remains available.
The MAX6694 operates at different operating-current
levels depending on how many external channels are in
use. Assume that I
the MAX6694 is converting the remote channel 1 and
I
verting the other channels. For the MAX6694 with
remote channel 1 and n other remote channels con-
nected, the operating current is:
Figure 2. SMBus Protocols
8
CC2
WRITE BYTE FORMAT
READ BYTE FORMAT
SEND BYTE FORMAT
_______________________________________________________________________________________
is the operating current when the MAX6694 is con-
S
S
S = START CONDITION.
P = STOP CONDITION.
S
I
CC
SLAVE ADDRESS: EQUIVA-
LENT TO CHIP SELECT LINE
ADDRESS
ADDRESS
= (2 x I
7 BITS
7 BITS
SLAVE ADDRESS: EQUIVA-
LENT TO CHIP-SELECT LINE OF
A 3-WIRE INTERFACE
ADDRESS
7 BITS
Operating-Current Calculation
CC1
WR
CC1
WR
SHADED = SLAVE TRANSMISSION.
/// = NOT ACKNOWLEDGED.
+ I
is the operating current when
CC2
ACK
ACK
WR
+ n x I
COMMAND BYTE: SENDS COM-
MAND WITH NO DATA, USUALLY
USED FOR ONE-SHOT COMMAND
COMMAND BYTE: SELECTS
FROM WHICH REGISTER YOU
ARE READING
COMMAND
COMMAND
8 BITS
CC2
8 BITS
ACK
)/(n + 3)
ACK
COMMAND BYTE: SELECTS
TO WHICH REGISTER YOU
ARE WRITING
ACK
P
COMMAND
8 BITS
S
From a software perspective, the MAX6694 appears as
a series of 8-bit registers that contain temperature mea-
surement data, alarm threshold values, and control bits.
A standard SMBus-compatible, 2-wire serial interface is
used to read temperature data and write control bits
and alarm threshold data. The same SMBus slave
address also provides access to all functions.
The MAX6694 employs four standard SMBus protocols:
write byte, read byte, send byte, and receive byte
(Figure 2). The shorter receive byte protocol allows
quicker transfers, provided that the correct data regis-
ter was previously selected by a read byte instruction.
Use caution with the shorter protocols in multimaster
systems, since a second master could overwrite the
command byte without informing the first master. Figure
3 is the SMBus write-timing diagram and Figure 4 is the
SMBus read-timing diagram.
The remote diode 1 measurement channel provides 11
bits of data (1 LSB = +0.125°C). All other temperature-
measurement channels provide 8 bits of temperature
data (1 LSB = +1°C). The 8 most significant bits (MSBs)
RECEIVE BYTE FORMAT
SLAVE ADDRESS: REPEATED
DUE TO CHANGE IN DATA-
FLOW DIRECTION
S
ADDRESS
7 BITS
ADDRESS
7 BITS
ACK
RD
DATA BYTE: DATA GOES INTO THE REGISTER
SET BY THE COMMAND BYTE (TO SET
THRESHOLDS, CONFIGURATION MASKS, AND
SAMPLING RATE)
RD
DATA
8 BITS
ACK
ACK
SMBus Digital Interface
DATA BYTE: READS FROM
THE REGISTER SET BY THE
COMMAND BYTE
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
8 BITS
DATA
8 BITS
ACK
///
///
P
1
P
P