ADM1024ARUZ ON Semiconductor, ADM1024ARUZ Datasheet - Page 21

• Manufacturer Part Number: ADM1024ARUZ
• Description: IC MONITOR SYS TEMP/VOLT 24TSSOP
• Manufacturer: ON Semiconductor

Specifications of ADM1024ARUZ

• Applications: PC's, PDA's
• Interface: Serial
• Voltage - Supply: 2.8 V ~ 5.5 V
• Package / Case: 24-TSSOP
• Mounting Type: Surface Mount
• Temperature Sensor Function: Temp Sensor
• Output Type: Digital
• Package Type: TSSOP
• Operating Temperature (min): 0C
• Operating Temperature (max): 100C
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 5.5V
• Full Temp Accuracy: +/- 2 C , +/- 3 C
• Digital Output - Bus Interface: SMBus
• Digital Output - Number Of Bits: 10 bit
• Supply Voltage (max): 12 V
• Supply Voltage (min): 2.5 V
• Maximum Operating Temperature: + 100 C
• Minimum Operating Temperature: 0 C
• Supply Current: 1.4 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

reasserted even if the temperature remains above the high
limit(s). However, INT will be reasserted if:
the temperature then rises above the new high limit on the
next monitoring cycle;
of Interrupt Status Register 2;
start off within limits then fall below the low limit, INT will
be asserted. Once cleared, it will not be reasserted unless:
The temperature rises above the high limit;
then falls below the new low limit;
of Interrupt Status Register 2;
An interrupt is generated by another source.
THERM Input/Output
logic input/output with an internal, 100 kW pullup resistor,
that provides a separate output for temperature interrupts
only. It is enabled by setting Bit 2 of Configuration Register 1.
The THERM output has two operating modes that can be
programmed by Bit 3 of Configuration Register 2 (address
4Ah). With this bit set to the default value of 0, the THERM
output operates in “Default” interrupt mode. With this bit set
to 1, the THERM output operates in “ACPI” mode.
while THERM is enabled, but if these are not required they can
be masked by writing a 1 to Bit 0 of Configuration Register 2
(address 4Ah). The THERM pin can also function as a logic
input for an external sensor, for example, a temperature sensor
such as the ADM22105 used in Figure 35. If THERM is taken
low by an external source, the analog output will be forced to
FFh to switch a controlled fan to maximum speed. This also
generates an INT output as previously described.
Default Mode
thermostat with hysteresis. THERM will go low and Bit 5 of
Interrupt Status Register 2 will be set, if the temperature
measured by any of the sensors exceeds the high limit
programmed for that sensor. It will remain asserted until
reset by reading Interrupt Status Register 2, by setting Bit 6
of Configuration Register 1, or when the temperature falls
below the low limit programmed for that sensor.
Once the interrupt has been cleared, it will not be
The temperature falls below the low limit for the sensor;
The high limit(s) is/are reprogrammed to a new value, and
The THERM pin is pulled low externally, which sets Bit 5
An interrupt is generated by another source.
Similarly, should the temperature measured by a sensor
The low limit(s) is/are reprogrammed, and the temperature
The THERM pin is pulled low externally, which sets Bit 5
The Thermal Management Input/Output (THERM) is a
Thermal interrupts can still be generated at the INT output
In Default mode, the THERM output operates like a
or:
or:
or:
or:
or:
or:
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21
be reasserted after the next temperature reading and
comparison if it remains above the high limit.
Register 1, it cannot be reasserted until this bit is cleared.
temperature limits at addresses 13h, 14h, 17h, or 18h is
exceeded for three consecutive measurements. When this
happens, the analog output will be forced to FFh to boost a
controlled cooling fan to full speed.
case, because errors caused by exceeding the hardware
temperature limits are stored in a separate register that is not
cleared by reading the status register. In this case, THERM
can only be cleared by setting Bit 0 of Configuration
Register 2.
falls at least 5 degrees below the limit for three consecutive
measurements.
ACPI Mode
temperature limits at addresses 13h, 14h, 17h, and 18h, not
to the software−programmed limits.
hardware temperature limit is exceeded for three
consecutive measurements. It will remain low until the
temperature falls at least 5 degrees below the limit for three
consecutive measurements. While THERM is low, the
analog output will go to FFh to boost a controlled fan to full
speed.
HARDWARE
TRIP POINT
HIGH LIMIT
LOW LIMIT
If THERM is cleared by reading the status register, it will
If THERM is cleared by setting Bit 6 of Configuration
THERM will also be asserted if one of the hardware
Reading Status Register 1 will not clear THERM in this
THERM will be cleared automatically if the temperature
In ACPI mode, THERM responds only to the hardware
THERM will go low if either the internal or external
ANALOG
OUTPUT
Figure 34. INT or THERM Output in Default Mode
THERM
ANALOG
THERM
OUTPUT
TEMP
TEMP
Figure 35. THERM Output in ACPI Mode
PROGRAMMED
PROGRAMMED
TEMP
VALUE
TEMP
VALUE
THERM CLEAR
CLEARED BY
READ OR
0xFF
TEMP FALLING
CLEARED BY
BELOW LOW
LIMIT
55
0xFF
0xFF
THERM
EXT
INPUT
THERM
INPUT
EXT