MCP9804 Microchip Technology, MCP9804 Datasheet - Page 18

• Manufacturer Part Number: MCP9804
• Description: Accuracy Digital Temperature Sensor
• Manufacturer: Microchip Technology

MCP9804
5.1.1
The MCP9804 has a 16-bit Configuration register
(CONFIG) that allows the user to set various functions
for a robust temperature monitoring system. Bits 10
thru 0 are used to select Temperature Alert output
hysteresis, device Shutdown or Low-Power mode,
temperature boundary and critical temperature lock,
and temperature Alert output enable/disable. In
addition, Alert output condition (output set for T
and T
Alert output status and Alert output polarity and mode
(Comparator Output or Interrupt Output mode) are user
configurable.
The temperature hysteresis bits 10 and 9 can be used
to
temperature
user-specified
REGISTER 5-2:
DS22203A-page 18
bit 15
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 15-11
bit 10-9
bit 8
Crit. Lock
prevent
R/W-0
U-0
LOWER
—
SENSOR CONFIGURATION
REGISTER (CONFIG)
temperature boundary or T
output
gradually
Unimplemented: Read as ‘0’
T
00 = 0°C (power-up default)
01 = 1.5°C
10 = 3.0°C
11 = 6.0°C
(Refer to Section 5.2.3)
This bit can not be altered when either of the lock bits are set (bit 6 and bit 7).
This bit can be programmed in shutdown mode.
Shutdown Mode (SHDN):
0 =
1 =
In shutdown, all power-consuming activities are disabled, though all registers can be written to or read.
This bit cannot be set ‘1’ when either of the lock bits is set (bit 6 and bit 7). However, it can be cleared
‘0’ for Continuous Conversion while locked. (Refer to Section 5.2.1).
UPPER
Win. Lock
temperature
R/W-0
U-0
—
CONFIGURATION REGISTER (CONFIG) → ADDRESS
Continuous Conversion (power-up default)
Shutdown (Low-Power mode)
chatter
and T
changes
LOWER
W = Writable bit
‘1’ = Bit is set
when
Int. Clear
R/W-0
boundary
U-0
—
Limit Hysteresis (T
beyond
the
CRIT
ambient
Alert Stat.
UPPER
only),
(see
U-0
R-0
—
the
HYST
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
Alert Cnt.
R/W-0
):
Section 5.2.2.
Shutdown mode is selected using bit 8. In Shutdown
mode, the band gap temperature sensor circuit stops
converting temperature and the Ambient Temperature
register (T
Section 5.2.1). Bits 7 and 6 are used to lock the user-
specified boundaries T
prevent an accidental rewrite. The Lock bits are cleared
by reseting power. Bits 5 thru 0 are used to configure
the temperature Alert output pin. All functions are
described in
U-0
—
A
) holds the previous temperature data (see
Register 5-2
Alert Sel.
R/W-0
R/W-0
The
T
‘0000 0001’b
HYST
UPPER
© 2009 Microchip Technology Inc.
Continuous
(see Section 5.2.3).
x = Bit is unknown
Alert Pol.
R/W-0
R/W-0
, T
LOWER
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Conversion
and T
Alert Mod.
R/W-0
SHDN
R/W-0
CRIT
bit 8
bit 0
or
to