L6728DTR STMicroelectronics

L6728D Single-phase PWM controller with Power Good Features Flexible power supply from 5 V to 12 V Power conversion input as low as 1.5 V 0.8 V internal reference 0.8% output voltage accuracy High-current integrated drivers DFN10 Power Good output Sensorless and programmable OCP across low-side R Description DS(on) OV / UV protection L6728D is a single-phase step-down controller VSEN disconnection protection with integrated high-current drivers that provides complete control logic and protection to simplify Oscillator internally fixed at 300 kHz the design of general DC-DC converters by using LSLess to manage pre-bias startup a compact DFN10 package. Adjustable output voltage Device flexibility allows the management of Disable function conversions with power input (V ) as low as IN 1.5 V, and device supply voltage ranging from 5 V Internal soft-start to 12 V. DFN10 package The L6728D provides a simple control loop with voltage mode EA. The integrated 0.8 V reference allows output voltages regulation with 0.8% Applications accuracy over line and temperature variations. The oscillator is internally fixed to 300 kHz. Memory and termination supply The L6728D provides programmable dual level Subsystem power supply (MCH, IOCH, PCI, overcurrent protection, as well as overvoltage and etc.) undervoltage protection. Current information is CPU and DSP power supply monitored across the low-side MOSFET R , DS(on) Distributed power supply eliminating the need for expensive and space- consuming sense resistors. General DC-DC converters A PGOOD output easily provides real-time information on output voltage status, through the VSEN dedicated output monitor. Table 1. Device summary Order codes Package Packaging L6728D Tube DFN10 L6728DTR Tape and reel February 2010 Doc ID 16498 Rev 1 1/33 www.st.com 33 Contents L6728D Contents 1 Typical application circuit and block diagram 4 1.1 Application circuit 4 1.2 Block diagram . 4 2 Pin description and connection diagram 5 2.1 Pin descriptions . 5 3 Thermal data . 6 4 Electrical specifications 7 4.1 Absolute maximum ratings . 7 4.2 Electrical characteristics . 7 5 Device description 9 6 Driver section . 10 6.1 Power dissipation . 10 7 Soft-start . 12 7.1 Low-side-less startup (LSLess) 12 8 Overcurrent protection 13 8.1 Overcurrent threshold setting 14 9 Output voltage setting and protections 15 10 Application details . 16 10.1 Compensation network 16 10.2 Layout guidelines . 18 11 Application information . 20 11.1 Inductor design . 20 11.2 Output capacitor(s) 21 11.3 Input capacitors 21 2/33 Doc ID 16498 Rev 1