Datasheet

© 2009 Microchip Technology Inc. DS22153C-page 43
MCP9843/98243
5.4 Summary of Power-on Default
The MCP9843/98243 has an internal Power-on Reset
(POR) circuit. If the power supply voltage V
DD
glitches
down to the V
POR_TS
and V
POR_EE
thresholds, the
device resets the registers to the power-on default
settings.
Table 5-6 shows the power-on default summary for the
temperature sensor. The EEPROM resets the address
pointer to 0x00 hex.
TABLE 5-6: MCP9843/98243 TEMPERATURE SENSOR POWER-ON RESET DEFAULTS
Registers
Default Register
Data (Hexadecimal)
Power-up Default
Register Description
Address
(Hexadecimal)
Register Name
0x00 Capability 0x00EF Event output de-asserts in shutdown
I
2
C time out 25 ms to 35 ms.
Accepts V
HV
at A0 Pin
0.25°C Measurement Resolution
Measures temperature below 0°C
±1°C accuracy over active range
Temperature event output
0x01 CONFIG 0x0000 Comparator mode
Active-Low output
Event and critical output
Output disabled
Event not asserted
Interrupt cleared
Event limits unlocked
Critical limit unlocked
Continuous conversion
0°C Hysteresis
0x02 T
UPPER
0x0000 0°C
0x03 T
LOWER
0x0000 0°C
0x04 T
CRIT
0x0000 0°C
0x05 T
A
0x0000 0°C
0x06 Manufacturer ID 0x0054 0x0054 (hex)
0x07 Device ID/ Device Revision for
MCP98243
0x2101 0x2101 (hex)
0x07 Device ID/ Device Revision for
MCP9843
0x0001 0x0001 (hex)
0x08 Resolution 0x01 0x01 (hex)