IES5523A Zero Crossing Triac Control -Time-Out & LED Indicator
The IES5523A extends the functionality of the IES5521A with an addition of a time-out indicator signal. It is intended as a cost effective temperature controller with automatic safety switch off with an output pin to indicate time-out mode. The time-out indicator pin on the IES5523A when used to drive an LED circuit can be set to either show power ON when running and power OFF when timed-out; or vice-versa. This feature in the IES5523A provides flexibility to inform the user of the current operating mode of the appliance. Unlike other temperature control solutions, the IES5523A provides the functionality to automatically switch the heater control off after a preset time. This could be the nominal 1-hour (50Hz/ 60Hz mains) or by adding an external resistor and capacitor a different time out time can be set. Switching the mains OFF and ON again easily resets the timer. Other features of the IES5523A include zero crossing triac triggering in applications where it is controlled by a resistive sensor such as an NTC thermistor. These features including small footprint of IES5523A, will give you the flexibility to easily design it into products such as control of heater elements in cookers, hair straighteners and others.
features
Accurate time-out using mains frequency or widely adjustable using external “RC” components Time-out timer automatically stops the triac operation at the end of the preset time Easy timer reset by switching mains off and on again Timeout indicator pin Zero crossing triac control		Direct AC mains powered (both 110V/240V Mains AC powered sensor Low supply current requirement Easy gate pulse width adjustment On chip protection against gate spikes Low external components
benefits
Automatic safety switch off Time-out indicator signal available for LED drive circuit Eliminates extra circuitry for time-out Eliminates the need for a RESET switch No external DC supply required Minimal RFI filtering circuit		Small PCB footprint Low external component count translates to low electronic circuitry cost Lifetime accuracy Proven reliability
applications
Hair styling tools Hair straighteners Hair crimpers Hair curlers/ curling irons Hair curling hot setters		Home heating appliances Electric frypan Deep fryer Electric iron Heating pads
application block diagram
This application circuit shows the IES5523A driving a 60W resistive heating load, with time-out period set via external resistor and capacitor. This circuit turns the LED off when it is in time-out mode.