MAX6633 MAXIM [Maxim Integrated Products], MAX6633 Datasheet - Page 10

• Manufacturer Part Number: MAX6633
• Description: 12-Bit Plus Sign Temperature Sensors with SMBus/I2C-Compatible Serial Interface
• Manufacturer: MAXIM [Maxim Integrated Products]

bit. Registers T
and contain values that trigger ALERT and OVERT.
Register T
values by which the temperature must rise or fall
beyond T
OVERT deassert.
An on-chip bandgap reference produces a signal pro-
portional to absolute temperature (PTAT), as well as the
temperature-stable reference voltage necessary for the
analog-to-digital conversion. The PTAT signal is digi-
tized by the on-board ADC to a resolution of 0.0625°C.
The resulting digital value is placed in the Temperature
register. The temperature conversion runs continuously
and asynchronously from the serial interface at a rate of
500ms per conversion. When the Temperature register
is read, the conversion in progress is aborted. The bus
transaction is completed by a stop condition.
12-Bit Plus Sign Temperature Sensors with
SMBus/I
Figure 9. Alarm Output and Reset Diagram
10
______________________________________________________________________________________
COMPARATOR MODE
COMPARATOR MODE
T
T
T
INTERRUPT MODE
HIGH
LOW
MAX
HYST
HIGH
+ T
- T
- T
ALERT
ALERT
OVERT
ONLY
T
T
T
HYST
HYST
HYST
HIGH
MAX
LOW
HIGH
is 16 bits, read/write, and contains the
, T
LOW
2
and T
C-Compatible Serial Interface
Temperature Conversion
, or T
LOW
MAX
are 16 bits, read/write,
*
, before ALERT or
OTHERWISE, IT WOULD REMAIN LOW INDEFINITELY UNTIL CLEARED.
*IN INTERRUPT MODE, READING THE DEVICE CLEARS ALERT.
*
A programmable fault queue on the MAX6634/
MAX6635 eliminates spurious alarm activity in noisy
environments. The queue sets the number of consecu-
tive out-of-tolerance temperature readings that must
occur before the ALERT or OVERT alarm outputs are
toggled. An out-of-tolerance reading is above T
T
1 at power-up and may be programmed—through the
Configuration register—to four consecutive conver-
sions. Any time the conversion result is in tolerance,
and the particular alarm output is not asserted, the
queue is cleared, even if it contains some out-of-toler-
ance counts. Additionally, the fault queue automatically
clears at power-up and in shutdown. Whenever the
fault queue is cleared, the alarm outputs are deassert-
ed. Figure 9 is the alarm output and reset diagram.
MAX
or below T
*
Fault Queue (MAX6634/MAX6635)
LOW
. The fault queue depth defaults to
*
*
HIGH
or