L6728TR STMicroelectronics

L6728 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 protections L6728 is a single-phase step-down controller with VSEN disconnection protection integrated high-current drivers that provides complete control logic and protection to realize in Oscillator internally fixed at 300 kHz a simple way general DC-DC converters by using LSless to manage pre-bias start-up a compact DFN10 package. Adjustable output voltage Device flexibility allows managing conversions Disable function with power input V as low as 1.5 V and device IN supply voltage ranging from 5 V to 12 V. Internal soft-start DFN10 package L6728 provides simple control loop with voltage mode EA. The integrated 0.8 V reference allows regulating output voltages with 0.8 % accuracy over line and temperature variations. Oscillator is Applications internally fixed to 300 kHz. Memory and termination supply L6728 provides programmable dual level over current protection as well as over and under Subsystem power supply (MCH, IOCH, PCI...) voltage protection. Current information is CPU and DSP power supply monitored across the low-side MOSFET R DS(on) Distributed power supply saving the use of expensive and space- consuming sense resistors. General DC-DC converters PGOOD output easily provides real-time information on output voltage status, through VSEN dedicated output monitor. Table 1. Device summary Order codes Package Packaging L6728 Tube DFN10 L6728TR Tape and reel November 2008 Rev 4 1/31 www.st.com 1 Obsolete Product(s) - Obsolete Product(s) Content L6728 Content 1 Typical application circuit and block diagram 4 1.1 Application circuit 4 1.2 Block diagram . 4 2 Pin description and connection diagrams . 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 . 11 7.1 Low-side-less start up (LSLess) 11 8 Over current protection . 12 8.1 Over current threshold setting . 13 9 Output voltage setting and protections 14 10 Application details . 15 10.1 Compensation network 15 10.2 Layout guidelines . 17 11 Application information . 19 11.1 Inductor design . 19 11.2 Output capacitor(s) 20 11.3 Input capacitors 20 2/31 Obsolete Product(s) - Obsolete Product(s)