lm96163cisdx-1 National Semiconductor Corporation, lm96163cisdx-1 Datasheet - Page 12

• Manufacturer Part Number: lm96163cisdx-1
• Description: Remote Diode Digital Temperature Sensor With Integrated Fan Control And Trutherm Bjt Transistor Beta Compensation Technology
• Manufacturer: National Semiconductor Corporation

www.national.com
Local Temperature and Remote T_CRIT setpoint data is rep-
resented by an 8-bit, two's complement, word with an LSb
equal to 1°C.
Remote T_CRIT setpoint data can also be represented by an
8-bit, unsigned, word with an LSb equal to 1°C.
Temperature
Temperature
Temperature
Temperature
+0.03125°C
−0.03125°C
+255.875°C
+0.03125°C
+125°C
+255°C
+201°C
+125°C
+125°C
+255°C
+150°C
+125°C
+25°C
−25°C
−55°C
+25°C
+25°C
−25°C
−55°C
+25°C
+1°C
−1°C
+1°C
+1°C
−1°C
+1°C
0°C
0°C
0°C
0°C
13-bit, 2's complement (12-bit plus sign)
8-bit, 2's complement (7-bit plus sign)
13-bit, unsigned binary
8-bit, unsigned binary
0111 1101 0000 0000
0001 1001 0000 0000
0000 0001 0000 0000
0000 0000 0000 1000
0000 0000 0000 0000
1111 1111 1111 1000
1111 1111 0000 0000
1110 0111 0000 0000
1100 1001 0000 0000
1111 1111 1110 0000
1111 1111 0000 0000
1100 1001 0000 0000
0111 1101 0000 0000
0001 1001 0000 0000
0000 0001 0000 0000
0000 0000 0000 1000
0000 0000 0000 0000
0111 1101
0001 1001
0000 0001
0000 0000
1111 1111
1110 0111
1100 1001
1111 1111
1001 0110
0111 1101
0001 1001
0000 0001
0000 0000
Binary
Binary
Binary
Binary
Digital Data
Digital Data
Digital Data
Digital Data
FFE0h
7D00h
FFF8h
FF00h
E700h
C900h
FF00h
C900h
7D00h
1900h
0100h
0008h
0000h
1900h
0100h
0008h
0000h
Hex
Hex
Hex
7Dh
FFh
E7h
C9h
Hex
FFh
7Dh
19h
01h
00h
96h
19h
01h
00h
12
1.6 OPEN-DRAIN OUTPUTS
The SMBDAT, ALERT, TCRIT and PWM outputs are open-
drain outputs and do not have internal pull-ups. A “High” level
will not be observed on these pins until pull-up current is pro-
vided by an internal source, typically through a pull-up resis-
tor. Choice of resistor value depends on several factors but,
in general, the value should be as high as possible consistent
with reliable operation. This will lower the power dissipation
of the LM96163 and avoid temperature errors caused by self-
heating of the device. The maximum value of the pull-up
resistor to provide the 2.1 V high level is 88.7 kΩ.
1.7 DIODE FAULT DETECTION
The LM96163 is equipped with operational circuitry designed
to detect remote diode fault conditions:
•
•
•
In the event that the D+ pin is grounded the Remote Temper-
ature reading is forced to –128.000 °C if signed format is read
and 0 °C if unsigned format is read. When the D+ pin is de-
tected as shorted to V
reading is forced to +127.000 °C if signed format is read and
+255.000 °C is unsigned format is read. In addition, the
ALERT Status register bit RDFA is set. Setting of the RDFA
bit will not cause ALERT or TCRIT to activate. Under fault
conditions remote diode setpoint comparisons will use these
forced temperature values therefore other bits in the ALERT
Status Register may be set thus activating the ALERT or
TCRIT outputs unless these bits are masked. The function of
the ALERT and TCRIT is fully described in Section 1.2
ALERT and TCRIT OUTPUTS.
1.8 COMMUNICATING WITH THE LM96163
Each data register in the LM96163 falls into one of four types
of user accessibility:
1.
2.
3.
4.
A Write to the LM96163 is comprised of an address byte and
a command byte. A write to any register requires one data
byte.
Reading the LM96163 Registers can take place after the req-
uisite register setup sequence takes place. See Section 2.1.1
LM96163 Required Initial Fan Control Register Sequence.
The data byte has the Most Significant Bit (MSB) first. At the
end of a read, the LM96163 can accept either Acknowledge
or No-Acknowledge from the Master. Note that the No-Ac-
knowledge is typically used as a signal for the slave indicating
that the Master has read its last byte.
D+ shorted to V
D+ open or floating
D+ shorted to GND.
Read Only
Write Only
Read/Write same address
Read/Write different address
DD
DD
or floating, the Remote Temperature