TS4431 1.224V Open Collector Shunt Voltage Reference Internal 1.224V 0.5% precision Low output saturation voltage 75 mV max between SINK and GND Low current consumption: 250A SOT23-5L (Plastic Micropackage) Industrial temperature range: -40 to +85C 100ppm/C temperature coefficient Pin connections (top view) Description The TS4431 is a four-terminal device dedicated to 1 Vc c Sink 5 low voltage Switch Mode Power Supplies (SMPS). It integrates a 1.224V voltage reference, an 2 Gnd amplifier, and an open collector output transistor in a single package. The TS4431s operating mode is similar to the well-known standard 34Nc Ref voltage reference, the TL431. It maintains the desired feedback voltage at the REF pin in a closed loop configuration by sinking a current proportional to the error voltage at the REF pin. Applications TS4431 features an open collector transistor with Low voltage switch mode power supplies an ultra-low saturation voltage, allowing it to be used in series with the optocoupler in an SMPS Isolated DC/DC converter architecture to regulate low voltage SMPS. Computers Low voltage discrete regulator Order Codes Part Number Accuracy Temperature Range Package Packing Marking TS4431AILT 0.5% L288 -40, +85C SOT23-5 Tape & Reel TS4431ILT 1% L275 Rev 2 November 2005 1/8 www.st.com 8Absolute Maximum Ratings TS4431 1 Absolute Maximum Ratings Table 1. Key parameters and their absolute maximum ratings Symbol Parameter Value Unit I Output sink current 30 mA SINK V Supply voltage 12 V CC V Output voltage 12 V SINK (1) P 500 mW D Power Dissipation SOT23-5 T Storage Temperature -65 to +150 C STD Human Body Model (HBM) 2 kV ESD Machine Model (MM) 200 V T Lead Temperature (soldering, 10 seconds) 250 C LEAD 1. P has been calculated with T = 25C, T =150C and D AMB Junction Rth = 250C/W for the SOT23-5 package JA Rth = 81C/W for the SOT23-5 package JC Table 2. Operating conditions Symbol Parameter Value Unit T Operating temperature range -40 to +85 C OPER V Supply voltage 1.5 to 10 V CC I Output sink current 20 mA SINK 2/8