MAX6698EE99+ Maxim Integrated Products, MAX6698EE99+ Datasheet - Page 6

• Manufacturer Part Number: MAX6698EE99+
• Description: IC TEMP MONITOR 7CH 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6698EE99+

• 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: 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: 16-QSOP
• Full Temp Accuracy: +/- 3.5 C, +/- 3 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Digital Output - Number Of Bits: 11 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX6698 is a precision multichannel temperature
monitor that features one local, three remote thermal
diode temperature-sensing channels, and three ther-
mistor voltage-sensing channels. All channels have a
programmable alert threshold for each temperature
channel and a programmable overtemperature thresh-
old for channels 1, 4, 5, and 6 (see Figure 1).
Communication with the MAX6698 is achieved through
the SMBus serial interface and a dedicated alert
(ALERT) pin. The alarm outputs, OVERT and ALERT,
assert if the software-programmed temperature thresh-
olds are exceeded. ALERT typically serves as an inter-
rupt, while OVERT can be connected to a fan, system
shutdown, or other thermal-management circuitry.
Note that thermistor “temperature data” is really the volt-
age across the fixed resistor, R
thermistor. This voltage is directly related to temperature,
but the data is expressed in percentage of the reference
voltage not in °C.
In the default conversion mode, the MAX6698 starts the
conversion sequence by measuring the temperature on
the channel 1 remote diode, followed by the channel 2,
remote diode, channel 3 remote diode, and the local
channel. Then it measures thermistor channel 1, ther-
mistor channel 2, and thermistor channel 3. The con-
7-Channel Precision Remote-Diode, Thermistor,
and Local Temperature Monitor
6
_______________________________________________________________________________________
PIN
10
11
12
13
14
15
16
9
SMBDATA
SMBCLK
OVERT
THER2
THER1
ALERT
NAME
GND
V
CC
ADC Conversion Sequence
Detailed Description
Thermistor Voltage Sense Input 2. Connect thermistor 2 between THER2 and ground and an external
resistor R
Thermistor Voltage Sense Input 1. Connect thermistor 1 between THER1 and ground and an external
resistor R
Overtemperature Active-Low, Open-Drain Output. OVERT asserts low when the temperature of
channels 1, 4, 5, and 6 exceed the programmed threshold limit.
Supply Voltage Input. Bypass to GND with a 0.1µF capacitor.
SMBus Alert (Interrupt), Active-Low, Open-Drain Output. ALERT asserts low when the temperature of
channels 1, 4, 5, and 6 exceed programmed threshold limit.
SMBus Serial-Data Input/Output. Connect to a pullup resistor.
SMBus Serial-Clock Input. Connect to a pullup resistor.
Ground
EXT
EXT3
EXT3
, in series with the
between THER2 and VREF.
between THER1 and VREF.
version result for each active channel is stored in the
corresponding temperature data register.
In some systems, one of the remote thermal diodes may
be monitoring a location that experiences temperature
changes that occur much more rapidly than in the other
channels. If faster temperature changes must be moni-
tored in one of the temperature channels, the MAX6698
allows channel 1 to be monitored at a faster rate than the
other channels. In this mode (set by writing a 1 to bit 4 of
the configuration 1 register), measurements of channel 1
alternate with measurements of the other channels. The
sequence becomes remote-diode channel 1, remote-
diode channel 2, remote-diode channel 1, remote-diode
channel 3, remote-diode channel 1, etc. Note that the
time required to measure all seven channels is consider-
ably greater in this mode than in the default mode.
Standby mode reduces the supply current to less than
15µA by disabling the internal ADC. Enter standby by
setting the STOP bit to 1 in the configuration 1 register.
During standby, data is retained in memory, and the
SMBus interface is active and listening for SMBus com-
mands. The timeout is enabled if a start condition is rec-
ognized on the SMBus. Activity on the SMBus causes
the supply current to increase. If a standby command is
received while a conversion is in progress, the conver-
sion cycle is interrupted, and the temperature registers
are not updated. The previous data is not changed and
remains available.
FUNCTION
Pin Description (continued)
Low-Power Standby Mode