MCP9808 MICROCHIP [Microchip Technology], MCP9808 Datasheet - Page 24

• Manufacturer Part Number: MCP9808
• Manufacturer: MICROCHIP [Microchip Technology]

MCP9808
5.1.3
The MCP9808 uses a band gap temperature sensor
circuit to output analog voltage proportional to absolute
temperature. An internal ΔΣ ADC is used to convert the
analog voltage to a digital word. The digital word is
loaded to a 16-bit read-only Ambient Temperature
register
two’s complement format.
The T
Therefore, the user can access the register, while in the
background, the MCP9808 performs an Analog-to-
Digital conversion. The temperature data from the ΔΣ
ADC is loaded in parallel to the T
refresh rate.
REGISTER 5-4:
DS25095A-page 24
bit 15
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 15
bit 14
bit 13
bit 12
bit 11-0
Note 1:
T
A
vs. T
2
R-0
R-0
A
3
2:
°C
(T
register bits (T
CRIT
A
Bits 15, 14 and 13 are not affected by the status of the Alert Output Configuration (CONFIG<5:0> bits,
Register
Bits 2, 1 and 0 may remain clear at ‘0’ depending on the status of the Resolution register
The power-up default is 0.25°C/bit; bits 1 and 0 remain clear ‘0’.
AMBIENT TEMPERATURE
REGISTER (T
)
(1)
that contains 13-bit temperature data in
T
0 = T
1 = T
T
0
1 = T
T
0 = T
1 = T
SIGN bit
0 = T
1 = T
T
12-bit ambient temperature data in two’s complement format.
T
A
A
A
A
A
= T
: Ambient Temperature bits
vs. T
vs. T
vs. T
vs. T
5-2).
2
A
A
A
A
A
A
A
A
T
R-0
R-0
2
A
A
< T
≥ T
≤ T
> T
≥ T
< T
≥ 0°C
< 0°C
UPPER
CRIT
UPPER
LOWER
<12:0>) are double-buffered.
°C
: AMBIENT TEMPERATURE REGISTER (→ ADDRESS ‘0000 0101’b)
CRIT
CRIT
UPPER
UPPER
LOWER
LOWER
A
)
bit
(1)
bit
(1)
bit
(1)
W = Writable bit
‘1’ = Bit is set
T
(1)
A
A
register at t
vs. T
2
R-0
R-0
1
LOWER
°C
(2)
(1)
CONV
SIGN
2
R-0
R-0
0
°C
In addition, the T
to reflect the Alert pin state. This allows the user to
identify the cause of the Alert output trigger (see
Section 5.2.3 “Alert Output
set to ‘1’ if T
set to ‘1’ if T
‘1’ if T
The T
conditions are described in
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
2
2
A
R-0
R-0
-1
7
A
is less than T
°C
°C
register bit assignment and boundary
A
A
is greater than T
is greater than or equal to T
A
2
register uses three bits (T
-2
2
R-0
R-0
6
°C
LOWER
°C
(2)
© 2011 Microchip Technology Inc.
Register
.
Configuration”); bit 15 is
x = Bit is unknown
UPPER
2
-3
2
R-0
R-0
5
°C
°C
and bit 13 is set to
5-4.
(2)
(Register
CRIT
A
2
(1)
<15:13>)
-4
, bit 14 is
2
R-0
R-0
4
5-7).
°C
°C
bit 8
bit 0
(2)