L6520 L6521 Highly integrated ballast controller for TL and CFL Features Half bridge circuit able to drive both BJT and MOSFET transistors Very accurate oscillator precision in wide SO8 operating temperature range BJTs storage time compensation Applications Preheated start and instant start Electronic ballasts (TL, Industrial CFL) Hard switching protection Integrated CFLs Overcurrent / voltage protection Choke saturation control Table 1. Device summary End-of-life protection Order codes Package Packaging Programmable without capacitors L6520 Tube L6520TR Tape and reel SO8 L6521 Tube L6521TR Tape and reel Figure 1. Block diagram 9&& 3:0BGHW 9FF 9FF 9 9 9 +6 6WDUW8S 89/2 9 9 ,QWHUQDO 9 5HJ /6 9 /2*,& (2/ 9 &25( ,1 7 + 7 0 7 / 9 7KUHVKROG 08 9FF +%&6 X &&& %ORFN )35( & *1 March 2011 Doc ID 16998 Rev 3 1/19 www.st.com 19 Obsolete Product(s) - Obsolete Product(s)Contents L6520, L6521 Contents 1 Description . 3 2 Pin connection 4 3 Maximum ratings 5 4 Electrical characteristics . 6 5 Functions description 9 5.1 Start-up . 9 5.2 Preheating and instant start 9 5.3 Ignition . 10 5.4 Run mode . 10 5.5 Storage time compensation network 10 5.6 Current control circuit (CCC) 11 5.6.1 Hard switching protection (HSP) 11 5.6.2 Overcurrent protection (OCPH) during ignition mode 11 5.6.3 Overcurrent protection (OCPL) during run mode 11 5.6.4 Choke saturation control (CSC) during ignition and run mode . 12 5.7 End of life (EOL) 12 5.8 Summary of protections 13 6 Typical electrical characteristics 14 7 Application examples . 15 8 Package mechanical data 16 9 Revision history . 18 2/19 Doc ID 16998 Rev 3 Obsolete Product(s) - Obsolete Product(s)