MAX1619MEE Maxim Integrated Products, MAX1619MEE Datasheet - Page 11

• Manufacturer Part Number: MAX1619MEE
• Description: IC TEMP SENSOR W/ALARM 16-QSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1619MEE

• Function: Thermometer, Thermostat
• Topology: ADC, Comparator, 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: 16-QSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

tems, since a second master could overwrite the com-
mand byte without informing the first master.
The temperature data format is 7 bits plus sign in two’s
complement form for each channel, with each data bit rep-
resenting 1°C (Table 2), transmitted MSB first. Measure-
ments are offset by +1/2°C to minimize internal rounding
errors; for example, +99.6°C is reported as +100°C.
Two registers store ALERT threshold limits, with high-
temperature (T
isters for the remote A/D channel. There are no
comparison registers for the local A/D channel. If either
measured temperature equals or exceeds the corre-
sponding alarm threshold value, an ALERT interrupt is
asserted. The power-on-reset (POR) state of the T
register is full scale (0111 1111, or +127°C). The POR
state of the T
Two additional alarm threshold registers control the
OVERT output (see OVERT Alarm Output section), T
and T
T
The OVERT output is an unlatched open-drain output that
behaves as a thermostat to control a fan (Figure 4). When
using the SMBus interface, the polarity of the OVERT pin
(active-low at POR) can be inverted via bit 5 in the config-
uration byte. OVERT’s current state can be read in the
status byte.
OVERT can also be used to control a fan without system
intervention. OVERT goes low when the remote tempera-
ture rises above T
temperature drops below T
settings for T
respectively) allow the MAX1619 to be used in stand-
alone thermostat applications where connection to an
SMBus serial bus isn’t required.
There is a continuity fault detector at DXP that detects
whether the remote diode has an open-circuit condi-
tion. At the beginning of each conversion, the diode
fault is checked, and the status byte is updated. This
fault detector is a simple voltage detector; if DXP rises
above V
source, a fault is detected. Note that the diode fault
isn’t checked until a conversion is initiated, so immedi-
ately after power-on reset the status byte indicates no
fault is present, even if the diode path is broken.
HYST
Remote/Local Temperature Sensor with Dual-
HYST
is +95°C.
CC
O O V V E E R R T T Alarm Output for Fan Control
. The POR state of T
LOW
- 1V (typical) due to the diode current
Alarm Outputs and SMBus Serial Interface
MAX
HIGH
register is 1100 1001 or -55°C.
MAX
______________________________________________________________________________________
) and low-temperature (T
and T
Alarm Threshold Registers
and won’t go high again until the
HYST
HYST
. The power-up default
Diode Fault Alarm
(+100°C and +95°C,
MAX
is +100°C, and
LOW
) reg-
HIGH
MAX
Table 2. Data Format (Two’s Complement)
Figure 4. Fan Control Application
+130.00
+127.00
+126.50
+126.00
+25.25
TEMP.
-25.00
-25.50
-54.75
-55.00
-65.00
-70.00
INTERFACE
+0.50
+0.25
-0.25
-0.50
-0.75
-1.00
(TO HOST)
0.00
(°C)
SERIAL
SMBUS
+3V TO +5.5V
2N3904
ROUNDED
TEMP.
+127
+127
+127
+126
(°C)
+25
-25
-25
-55
-55
-65
-65
+1
-1
-1
0
0
0
0
SMBCLK
SMBDATA
ALERT
DXP
DXN
ADD0
ADD1
GND
STBY
MAX1619
SIGN
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
PGND
V
DIGITAL OUTPUT
CC
OVERT
DATA BITS
MSB
111
111
111
111
001
000
000
000
000
000
111
111
110
110
100
100
011
011
+12V
1111
1111
1111
1110
1001
0001
0000
0000
0000
0000
1111
1111
0111
0111
1001
1001
1111
1111
LSB
11