cat6095 ON Semiconductor, cat6095 Datasheet - Page 14

• Manufacturer Part Number: cat6095
• Description: Digital Output Temperature Sensor
• Manufacturer: ON Semiconductor

CAT6095
REGISTER DATA FORMAT
The values used in the temperature value register
and the 3 temperature trip point registers are
expressed
measured temperature value is expressed with 12-bit
resolution, while the 3 trip temperature limits are set
with 10-bit resolution. The total temperature range is
arbitrarily defined as 256°C, thus yielding an LSB of
0.0625°C for the measured temperature and 0.25°C
for the 3 limit settings. Bit D12 in all temperature
registers represents the sign, with a ‘0’ indicating a
positive, and a ‘1’ a negative value. In two’s
complement format, negative values are obtained by
complementing their positive counterpart and adding
a ‘1’, so that the sum of opposite signed numbers, but
of equal absolute value, adds up to zero.
Note that trailing ‘0’ bits, are ‘0’ irrespective of
polarity. Therefore the don’t care bits (D1 and D0) in
the 10-bit resolution temperature limit registers, are
always ‘0’. Also note that temperatures below −20°C
will produce erroneous readings.
12-Bit Temperature Data Format
Doc. No. MD-1124 Rev. B
Binary (D12 to D0)
1 1110 1100 0000
1 1111 1111 1111
0 0000 0000 0000
0 0000 0000 0001
0 0001 1001 0000
0 0011 0010 0000
0 0111 1101 0000
in
two’s
complement
1EC0
1FFF
Hex
7D0
000
001
190
320
Temperature
format.
−0.0625°C
+0.0625°C
+125°C
−20°C
+25°C
+50°C
0°C
The
14
EVENT PIN FUNCTIONALITY
The EVENT
illustrated in Figure 8, and according to the operating
mode defined by the Configuration register.
In Interrupt Mode the EVENT
asserted every time the temperature crosses one of
the alarm window limits, and can be de-asserted by
writing a ‘1’ to the clear event bit in the configuration
register. When the temperature exceeds the critical
limit, the device switches to comparator mode and
¯¯¯¯¯¯
EVENT
temperature stays above the critical limit (setting the
clear event bit will have no effect in this case). When
the temperature drops below the critical limit, the
device
comparator
configuration register.
In Comparator Mode, the EVENT
outside the alarm window limits, while in Critical
Temperature Mode, EVENT
the critical limit. The exact trip limits are determined
by the 3 temperature limit settings and the hystersis
offsets, as dictated by the corresponding Configu-
ration register bits (see also Figure 9).
The EVENT
shut-down command.
¯¯¯¯¯¯ output reacts to temperature changes as
¯¯¯¯¯¯ output will retain the state preceding a
switches
remains
mode,
back
asserted
¯¯¯¯¯¯ is asserted only above
as
Characteristics subject to change without notice
¯¯¯¯¯¯ output is asserted
¯¯¯¯¯¯ output can be
to
programmed
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either
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