STEVAL-ISA026V1 STMicroelectronics

L6732 Adjustable step-down controller with synchronous rectification Features Input voltage range from 1.8 V to 14 V Supply voltage range from 4.5 V to 14 V Adjustable output voltage down to 0.6 V with 0.8 % accuracy over line voltage and temperature (0 C~125 C) Fixed frequency voltage mode control HTSSOP16 (exposed pad) T lower than 100 ns ON 0 % to 100 % duty cycle External input voltage reference Soft-start and inhibit High current embedded drivers Predictive anti-cross conduction control Programmable high-side and low-side R DS(on) sense over-current-protection Applications Selectable switching frequency 250 kHz / 500 kHz LCD and PDP TV Pre-bias start up capability High performance / high density DC-DC Power good output modules Master/slave synchronization with 180 phase Low voltage distributed DC-DC shift niPoL converters Over voltage protection DDR memory supply Thermal shutdown Graphic cards Package: HTSSOP16 Table 1. Device summary Order codes Package Packing L6732 HTSSOP16 Tube L6732TR HTSSOP16 Tape and reel June 2008 Rev 6 1/37 www.st.com 37Contents L6732 Contents 1 Summary description 3 1.1 Functional description 4 2 Electrical data 5 2.1 Maximum rating . 5 2.2 Thermal data . 5 3 Pin connection and function 6 4 Electrical characteristics . 8 5 Device description . 10 5.1 Oscillator . 10 5.2 Internal LDO . 10 5.3 Bypassing the LDO to avoid the voltage drop with low Vcc . 11 5.4 Internal and external references 11 5.5 Error amplifier 12 5.6 Soft-start 12 5.7 Driver section 15 5.8 Monitoring and protections 15 5.9 Thermal shutdown 17 5.10 Synchronization 17 5.11 Minimum on-time (TON, MIN) . 19 5.12 Bootstrap anti-discharging system 20 5.12.1 Fan s power supply 20 6 Application details . 21 6.1 Inductor design . 21 6.2 Output capacitors . 22 6.3 Input capacitors 22 6.4 Compensation network 23 7 L6732 demonstration board 26 2/37