STCC08 AC switch failure mode detector Features 3.3 V and 5 V power supply compatible ACS, ACST, TRIAC compatible Gate driver output: 28 mA max sink current Adjustable gate drive current SO-8 Sense the AC switch voltage in both AC line polarities Diode mode failure detection for solid state AC switches Applications Short circuit failure detection for AC switches, Home appliances relays, electromechanical switches ACS, ACST, TRIAC drive Open AC switch detection for AC switches, AC switch failure modes detection relays, electromechanical switches Zero voltage synchronization SO-8 SMD package Benefits Description Enable appliances to meet IEC 60335-1 and The STCC08 is an AC switch failure mode IEC 60730-1 standards detector and an AC power switch driver. It drives Enable appliances to meet IEC 61000-4-4 the AC switch and informs the MCU of switch standard failure. The MCU takes the appropriate actions to put the system in a secure state. Eliminates high DC current in inductive load, by detecting the diode mode failure Diode-mode, short circuit detection and open switch in both AC line polarities are detected. Improve system safety monitoring open switch failure with critical loads such as door locks The STCC08 helps home appliances to meet the Enable MCU to sense all AC switch failure IEC 60335-1 safety standard. modes and protect the appliance The STCC08 can be easily interfaced to an MCU Less MCU pin allocated to AC failure detection with its CMOS input AC switch driver and CMOS multiple STCC08 designed with resistor compatible output for the failure mode detector. dividers uses one I/O Easy to drive with MCU directly connected or through an opto coupler Highly compact with integrated solution in SMD version March 2008 Rev 1 1/13 www.st.com 13Characteristics STCC08 1 Characteristics Figure 1. Circuit block diagram GATE DRIVER G IN + - R IG V CC AVF AVF DRIVER AC POWER SWITCH GND SIGNAL SHAPING Table 1. Circuit pin descriptions Symbol Type Description IN SIGNAL Logic AC switch drive AVF SIGNAL Alternating voltage feedback: AC switch status output AC SIGNAL AC switch status sense input V POWER Positive power supply CC G SIGNAL AC switch gate driver output R SIGNAL AC switch gate current setting IG GND POWER Power supply reference Figure 2. Pin layout (top view) ININ GNDGND AVAVFF RR IGIG N/CN/C GG ACAC VV CCCC 2/13