LM89CIMM National Semiconductor, LM89CIMM Datasheet - Page 16

• Manufacturer Part Number: LM89CIMM
• Manufacturer: National Semiconductor

Specifications of LM89CIMM

• Temperature Sensor Function: Temp Sensor
• Interface Type: Serial (2-Wire)
• Output Type: Digital
• Package Type: MSOP
• Operating Temperature (min): 0C
• Operating Temperature (max): 125C
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (min): 3V
• Operating Supply Voltage (typ): 3.3V
• Operating Supply Voltage (max): 3.6V
• Lead Free Status / Rohs Status: Not Compliant

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2.0 LM89 Registers
For RTOHB: Remote Temperature Offset High Byte. Power up default is LHIGH = RHIGH = 0˚C. 1 LSB = 1˚C. Two’s complement
format.
For RTOLB: Remote Temperature Offset High Byte. Power up default is 0˚C. 1 LSB = 0.125˚C. Two’s complement format.
The offset value written to these registers will automatically be added to or subtracted from the remote temperature measurement
that will be reported in the Remote Temperature registers.
2.9 LOCAL and REMOTE T_CRIT REGISTERS (RCS and LCS)
D7–D0: T_CRIT setpoint temperature data. Power up default is Local T_CRIT = 85˚C and Remote T_CRIT=110˚C. 1 LSB = 1˚C,
two’s complement format.
2.10 T_CRIT HYSTERESIS REGISTER (TH)
D7–D0: T_CRIT Hysteresis temperature. Power up default is TH = 10˚C. 1 LSB = 1˚C, maximum value = 31.
2.11 FILTER and ALERT CONFIGURE REGISTER
D7-D3: is not defined defaults to "0".
D2-D1: input filter setting as defined the table below:
Level 2 sets maximum filtering.
D0: when set to "1" comparator mode is enabled.
2.12 MANUFACTURERS ID REGISTER
(Read Address FEh) The default value is 01h.
2.13 DIE REVISION CODE REGISTER
(Read Address FFh) The LM89 version has a default value of 31h or 49 decimal. The LM89-1 version has a default value of 34h
or 52 decimal. This register will increment by 1 every time there is a revision to the die by National Semiconductor.
3.0 Applications Hints
The LM89 can be applied easily in the same way as other
integrated-circuit temperature sensors, and its remote diode
sensing capability allows it to be used in new ways as well.
It can be soldered to a printed circuit board, and because the
path of best thermal conductivity is between the die and the
pins, its temperature will effectively be that of the printed
circuit board lands and traces soldered to the LM89’s pins.
This presumes that the ambient air temperature is almost the
same as the surface temperature of the printed circuit board;
(Read and Write Address BFh):
Value
BIT
(Read/Write Address 12h):
(Read/Write Address 20h, 19h):
(Read and Write Address 21h):
Value
Value
Value
BIT
BIT
BIT
(Continued)
D7
0
SIGN
0.5
D7
D7
D7
D6
0
D2
0.25
0
0
1
1
D6
D6
D6
64
D5
0
0.125
D5
D5
D5
32
D4
0
D1
16
0
1
0
1
D4
D4
D4
16
16
0
if the air temperature is much higher or lower than the
surface temperature, the actual temperature of the LM89 die
will be at an intermediate temperature between the surface
and air temperatures. Again, the primary thermal conduction
path is through the leads, so the circuit board temperature
will contribute to the die temperature much more strongly
than will the air temperature.
To measure temperature external to the LM89’s die, use a
remote diode. This diode can be located on the die of a
target IC, allowing measurement of the IC’s temperature,
independent of the LM89’s temperature. The LM89 has been
D3
0
D3
D3
D3
0
8
8
Filter Level
No Filter
Level 1
Level 1
Level 2
D2
Filter Level
D2
D2
D2
0
4
4
D1
D1
D1
D1
0
2
2
Configure
ALERT
D0
D0
D0
D0
0
1
1