TCN75
3.6
Comparator/Interrupt Modes
INT/CMPTR behaves differently depending on whether
the TCN75 is in Comparator mode or Interrupt mode.
Comparator mode is designed for simple thermostatic
operation. INT/CMPTR will go active anytime TEMP
exceeds T
SET
. When in Comparator mode, INT/
CMPTR will remain active until TEMP falls below
T
HYST
, whereupon it will reset to its inactive state. The
state of INT/CMPTR is maintained in Shutdown mode
when the TCN75 is in Comparator mode. In Interrupt
mode, INT/CMPTR will remain active indefinitely, even
if TEMP falls below T
HYST
, until any register is read via
the 2-wire bus. Interrupt mode is better suited to inter-
rupt driven microprocessor-based systems. The INT/
CMPTR output may be wire-OR’ed with other interrupt
sources in such systems. Note that a pull-up resistor is
necessary on this pin since it is an open-drain output.
Entering Shutdown mode will unconditionally reset INT/
CMPTR when in Interrupt mode.
©
2006 Microchip Technology Inc.
DS21490C-page 7
MICROCHIP [ MICROCHIP TECHNOLOGY ]
