Rainbow Electronics MAX6662 - Manual (Page 5)

MAX6662
12-Bit + Sign Temperature Sensor with
SPI-Compatible Serial Interface
_______________________________________________________________________________________ 5
For example: If T HIGH is set to 100°C and T HYST is set
to 20°C,
ALERT does not assert until temperature
exceeds 100°C. If the temperature is then read through
the serial interface,
ALERT deasserts. ALERT asserts
again when temperature is less than 80°C (Figure 2).
Comparator Mode
In the comparator mode, ALERT is asserted when tem-
perature exceeds the value in the T HIGH register, or is
lower than the value in the T LOW register.
ALERT
deasserts when temperature is less than T HIGH - T HYST
or greater than T LOW + T HYST . Reading the registers
does not deassert
ALERT.
For example: If T HIGH is set to 100°C and T LOW is set
to 80°C,
ALERT does not assert until temperature
exceeds 100°C, or is below 80°C. Then, ALERT only
deasserts if temperature is less than T HIGH - T HYST or
greater than T LOW + T HYST .
Overtemperature Alert
OT operates only in comparator mode. The OT pin is
asserted when the temperature exceeds T
MAX , and
deasserted when the temperature drops below
T
MAX - T HYST . A read operation does not reset
OT.
OT is an open-drain active-low (default) output, but can
be programmed to active-high.
TEMPERATURE
OT
SERIAL INTERFACE
V CC
SIO
SCLK
CONFIGURATION
CS
ALERT
T LOW T HIGH T MAX T HYST
12 -BIT
+ SIGN
ADC
Figure 1. MAX6662 Simplified Functional Diagram
T HIGH - T HYST
T
HIGH
T
LOW
T LOW + T HYST
ALERT
TEMPERATURE
LAST INTERRUPT MISSED, BUT
THRESHOLD STILL CHANGES TO T HIGH .
* * * * TEMPERATURE READ
Figure 2. Example of ALERT Operation in Interrupt Mode