PM8903TR STMicroelectronics

PM8903 3 A step-down monolithic switching regulator Features Integrated 35 m MOSFETs for high efficiency 3 A continuous output current 2.8 V to 6 V input voltage (VIN) 2.9 V to 5.5 V supply voltage (VCC) VFQFPN16 3x3 mm Adjustable output voltage down to 0.6 V 1% output voltage accuracy Description 1.1 MHz switching frequency operation The PM8903 is a high efficiency monolithic step- PSKIP mode to optimize light load efficiency down switching regulator designed to deliver up to Embedded bootstrap diode 3 A continuous current. The IC operates from 2.8 Thermally compensated loss-less current V to 6 V input voltage (VIN). sense across HS and LS MOSFETs The PM8903 features low-resistance integrated OV/UV/OC and overtemperature protection nMOS and proprietary pulse-skipping mode for Internal soft-start and soft-stop optimum efficiency over all the loading range. Interleaving synchronization (Up to 2 ICs) The voltage mode control loop allows the widest range of output filter. Current sense is internally Power Good output thermally compensated for optimum precision. Shutdown function (<15 A quiescent current) The integrated 0.6 V reference allows the VFQFPN16 3 x 3 mm compact package regulation of output voltages with 1% accuracy over temperature variations. Switching frequency Applications is typically set to 1.1 MHz and can be programmed to 0.8 MHz or 1.0 MHz. Out of phase Subsystem power supply synchronization allows the reduction of input RMS CPU, DSP and FPGA power supply current. Distributed power supply The PM8903 provides precise dual-threshold General DC-DC converters overcurrent protection as well as over / undervoltage and overtemperature protection. PGOOD output easily provides real-time information on the output voltage. The PM8903 is available in VFQFPN16 3 x 3 mm. Table 1. Device summary Order codes Package Packing PM8903 VFQFPN16 3x3 mm Tube PM8903TR VFQFPN16 3x3 mm Tape and reel February 2012 Doc ID 022748 Rev 1 1/34 www.st.com 34Contents PM8903 Contents 1 Typical application circuit and block diagram 3 1.1 Application circuit 3 1.2 Block diagram . 3 2 Pin description and connection diagrams . 4 2.1 Pin description 4 3 Thermal data . 6 4 Electrical specifications 7 4.1 Absolute maximum ratings . 7 4.2 Recommended operating conditions . 7 4.3 Electrical characteristics . 8 4.4 Typical operating characteristics 9 5 Device description . 11 5.1 Power section 11 5.2 Startup and shutdown management 12 5.2.1 Low-side-less startup . 13 5.2.2 Soft-off 13 5.3 Output voltage monitoring and protection 13 5.3.1 Overvoltage protection 13 5.3.2 Undervoltage protection . 14 5.3.3 Feedback disconnection protection 14 5.3.4 Power Good (PGOOD) . 14 5.4 Overcurrent protection . 15 5.5 Overtemperature protection . 15 5.6 Synchronization 15 5.7 Pulse-skipping . 16 5.8 Multifunction pin PSKIP/MS . 16 6 Application information . 17 6.1 Compensation network 17 2/34 Doc ID 022748 Rev 1