1°C Accurate Remote/Local Temperature
Sensor with SMBus Serial Interface
Table 5. Command-Byte Bit Assignments
REGISTER
RLTS
RRTE
RSL
ADDRESS
00h
POR STATE
0000 0000
0000 0000
0000 0000
0000 0000
0000 0010
0111 1111
1100 1001
0111 1111
1100 1001
N/A
FUNCTION
Read Internal Temperature
Read External Temperature
Read Status Byte
01h
02h
RCL
03h
Read Configuration Byte
Read Conversion Rate Byte
Read Internal High Limit
Read Internal Low Limit
Read External High Limit
Read External Low Limit
Write Configuration Byte
Write Conversion Rate Byte
Write Internal High Limit
Write Internal Low Limit
Write External High Limit
Write External Low Limit
One-Shot
RCRA
RLHN
RLLI
04h
05h
06h
RRHI
07h
RRLS
WCA
08h
09h
WCRW
WLHO
WLLM
WRHA
WRLN
OSHT
RRET
RLET
N/A
0Ah
0Bh
0Ch
0Dh
0Eh
0Fh
N/A
N/A
N/A
N/A
N/A
N/A
10h
0000 0000
0000 0000
4D
Read External Extended Temperature
Read Internal Extended Temperature
Read Device ID
11h
FEh
FFh
N/A
08
Read Device Revision
Table 6. Configuration-Byte Bit Assignments
BIT
NAME
MASK1
RUN/STOP
ETA
POR STATE
FUNCTION
7 (MSB)
0
0
0
0
0
0
Masks ALERT interrupts if high.
6
Standby mode control bit; if high, standby mode is initiated.
If high, lower temperature range will be extended from 0°C to -64°C.
If high, parasitic resistance cancellation mode is enabled.
Set high for operation with CPU.
5
4
PRCM
SPNP
3
2 to 0
RFU
Reserved.
cleared. The fault condition must be eliminated before
Status Byte Functions
the ALERT can be cleared.
The status byte register (Table 7) indicates which (if
any) temperature thresholds have been exceeded. This
byte also indicates whether the ADC is converting and
whether there is an open circuit in the remote diode
DXP–DXN path. After POR, the normal state of all the
flag bits is zero, assuming none of the alarm conditions
are present. The status byte is cleared by any success-
ful read of the status byte, unless the fault persists.
Note that the ALERT interrupt latch is not automatically
cleared when the status flag bit indicating the ALERT is
When reading the status byte, check for internal bus
collisions caused by asynchronous ADC timing, or else
disable the ADC prior to reading the status byte
(through the RUN/STOP bit in the configuration byte). In
one-shot mode, read the status byte only after the con-
version is complete, which is 150ms max after the one-
shot conversion is commanded.
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