UC1730

The UC1730 family of integrated circuit devices are designed to be used in  number of thermal monitoring applications. Each IC combines a temperature ransducer, precision reference, and temperature comparator allowing he device to respond with a logic output if temperatures exceed a user programmed evel. The reference on these devices is capable of supplying in xcess of 250mA of output current - by setting a level of power dissipation he rise in die temperature will vary with airflow past the package, allowing he IC to respond to airflow conditions .

These devices come in an 8-Pin DIP, plastic or ceramic, a 5-Pin TO-220 or a LCC-20 version. In the 8-Pin version, a PTAT (proportional to absolute emperature) output reports die temperature directly. This output is configured uch that its output level can be easily scaled up with two external gain esistors. A second PTAT source is internally referenced to the temperature omparator. The other input to this comparator can then be externally programmed o set a temperature threshold. When this temperature threshold s exceeded an alarm delay output is activated. Following the activation of he delay output, a separate open collector output is turned on. The delay in can be programmed with an external RC to provide a time separation etween activation of the delay pin and the alarm pin, permitting shutdown iagnostics in applications where the open collector outputs of multiple parts re wire OR'ed together. he 5-Pin version in the TO-220 package is well suited for monitoring eatsink temperatures. Enhanced airflow sensitivities can be obtained with is package by mounting the device to a small heatsink in the airstream. his version of the device does not include the PTAT output or the open collector larm output.