MAX6654MEE-T Maxim Integrated Products, MAX6654MEE-T Datasheet - Page 11

• Manufacturer Part Number: MAX6654MEE-T
• Description: Board Mount Temperature Sensors
• Manufacturer: Maxim Integrated Products

Specifications of MAX6654MEE-T

• Full Temp Accuracy: +/- 5 C
• Package / Case: QSOP-16
• Digital Output - Bus Interface: Serial (2-Wire, I2C)
• Digital Output - Number Of Bits: 10 bit + Sign
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Output Type: Digital
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

When the conversion rate is greater than 1Hz, tempera-
ture data can be read from the read internal tempera-
ture (00h) and read external temperature (01h)
registers. The temperature data format is 7 bits plus
sign in two’s-complement form for each channel, with
the LSB representing 1°C (Table 2), transmitted MSB
first. When the conversion rate is less than 1Hz, the
extended data can be read from the read external
extended temperature register (10h) and the read inter-
nal extended temperature register (11h), and the first 3
bits of the register represent 1/2, 1/4, and 1/8 of a
degree. Measurements are offset by +1/2°C to mini-
mize quantization errors; for example, +99.6°C is
reported as +100°C.
When the conversion rate is 1Hz or less, the first 8 bits
of temperature data can be read from the read internal
temperature (00h) and read external temperature (01h)
registers, the same as for faster conversion rates. An
additional 3 bits can be read from the read external
Table 2. Data Format
Table 3. Extended Resolution Register
(short or open)
<0.00 (Note 1)
TEMP (°C)
Diode fault
130.00
127.00
126.00
25.25
<-64
0.50
0.00
TEMPERATURE
-1
FRACTIONAL
0.000
0.125
0.250
0.375
0.500
0.625
0.750
0.875
1°C Accurate Remote/Local Temperature
______________________________________________________________________________________
(Extended temp mode)
(Extended temp mode)
ROUNDED TEMP (°C)
(Normal mode)
+127
+127
+126
+25
+1
0
Sensor with SMBus Serial Interface
DIGITAL OUTPUT
000X XXXX
001X XXXX
010X XXXX
011X XXXX
100X XXXX
101X XXXX
110X XXXX
111X XXXX
0 111 1111
0 111 1111
0 111 1110
0 001 1001
0 000 0001
0 000 0000
1 000 0000
1 111 1111
1 000 0000
1 000 0000
OUTPUT
DIGITAL
extended temperature and read internal extended tem-
perature registers, which extend the resolution to
0.125°C per LSB (Table 3).
If a conversion ends after reading the main register but
before reading the extended register, the extended
register will contain the 3LSBs from the new conversion
while the main register will contain the 8MSBs from the
previous conversion. The extended data in this case
will be meaningless. To avoid this problem, read
extended resolution temperature data using one of the
following approaches:
1) Put the MAX6654 into standby mode by setting bit 6
2) If the MAX6654 is in run mode and the conversion
Note: Extended resolution applies only for conversion
speeds of 1Hz and below.
Four registers store alarm threshold data, with high-
temperature (T
isters for each A/D channel. If either measured
temperature equals or exceeds the corresponding
alarm threshold value, an ALERT interrupt is asserted.
The POR state of both T
(0111 1111, or +127°C). The POR state of both T
registers is 1100 1001 or -55°C.
There is a continuity fault detector at DXP that detects
whether the remote diode has an open-circuit condition
or if DXP is shorted to DXN, GND, or V
circuit exists, then the temperature register will be
loaded with 1000 0000, and bit 3 of the status register
will be set to 1 at the end of a conversion. This means
that immediately after POR the status byte will indicate
no fault is present until the end of the first conversion.
of the configuration register to 1. Initiate a one-shot
conversion using Command Byte 0Fh. When this
conversion is complete, read the contents of the
temperature data registers.
rate is not set to either 1Hz or 8Hz, read the Status
Byte. If the BUSY bit indicates that a conversion is
in progress, wait until the conversion is complete as
indicated by the BUSY bit. Then immediately read
the contents of the temperature data registers. If no
conversion is in progress, the data can be read
within a few µs, which is a sufficiently short period
to ensure that a new conversion can’t be completed
until after the data has been read.
HIGH
) and low-temperature (T
Alarm Threshold Registers
HIGH
Diode Fault Alarm
registers is full scale
CC
. If an open
LOW
) reg-
LOW
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