MCP9800A0-M/MS MICROCHIP [Microchip Technology], MCP9800A0-M/MS Datasheet - Page 25

• Manufacturer Part Number: MCP9800A0-M/MS
• Description: 2-Wire High-Accuracy Temperature Sensor
• Manufacturer: MICROCHIP [Microchip Technology]

5.3.4.6
The fault queue feature can be used as a filter to lessen
the probability of spurious activation of the ALERT pin.
T
number of conversion cycles selected using the Fault
Queue bits. Bit 3 and bit 4 of CONFIG can be used to
select up to six fault queue cycles. For example, if six
fault queues are selected, T
T
asserted as a comparator or an interrupt output.
This queue setting also applies for T
queues are selected, T
six
deasserted (Comparator mode) or before another
interrupt is asserted (Interrupt mode).
5.3.4.7
The MCP9800/1/2/3 provides access to select the ADC
resolution from 9-bit to 12-bit (0.5°C to 0.0625°C
resolution) using bit 6 and bit 5 of the CONFIG register.
The user can gain better insight into the trends and
characteristics of the ambient temperature by using a
finer resolution. Increasing the resolution also reduces
the quantization error.
versus resolution.
Table 5-3
corresponding resolution.
TABLE 5-3:
 2010 Microchip Technology Inc.
A
SET
must remain above T
Bits
consecutive
for six consecutive conversions before ALERT is
10
11
12
9
shows the T
Fault Queue
 ADC Resolution
Resolution
RESOLUTION AND
CONVERSION TIME
conversions
0.0625
0.125
0.25
A
0.5
A
register conversion time for the
must remain below T
Figure 2-3
SET
A
must be greater than
for the consecutive
before
t
shows accuracy
CONV
HYST
120 ms
240 ms
30 ms
60 ms
.
ALERT
(typical)
I
f six fault
HYST
for
is
5.4
The MCP9800/1/2/3 has an internal Power-on Reset
(POR) circuit. If the power supply voltage V
down to the 1.7V (typical) threshold, the device resets
the registers to the power-up default settings.
Table 5-4
TABLE 5-4:
At power-up, the MCP9800/1/2/3 has an inherent 2 ms
(typical) power-up delay before updating the registers
with default values and start a conversion cycle. This
delay reduces register corruption due to unsettled
power. After power-up, it takes t
to update the T
Register
CONFIG
Pointer
T
T
HYST
T
SET
Summary of Power-up Condition
A
shows the power-up default summary.
A
MCP9800/1/2/3
register with valid temperature data.
POWER-UP DEFAULTS
(Hex)
0000
A000
9600
Data
00
00
Continuous Conversion
Comparator mode
Active-low Output
Fault Queue 1
9-bit Resolution
Temperature register
Power-up Defaults
CONV
DS21909C-page 25
for the TCN75A
80°C
75°C
0°C
DD
glitches