SiC417 Vishay Siliconix TM microBUCK SiC417 10-A, 28-V Integrated Buck Regulator with Programmable LDO DESCRIPTION FEATURES The Vishay Siliconix SiC417 is an advanced stand-alone High efficiency > 92 % synchronous buck regulator featuring integrated power Internal power MOSFETs: MOSFETs, bootstrap diode, and a programmable LDO in a High-side R = 27 m DS(ON) space-saving MLPQ 5 x 5 - 32 pin package. Low-side R = 9 m DS(ON) The SiC417 is capable of operating with all ceramic solutions Integrated bootstrap diode and switching frequencies up to 1 MHz. The programmable Integrated configurable 150 mA LDO with bypass logic frequency, synchronous operation and selectable Temperature compensated current limit power-save allow operation at high efficiency across the full Pseudo fixed-frequency adaptive on-time control range of load current. The internal programmable LDO may be used to supply 5 V for the gate drive circuits or it may be All ceramic solution enabled bypassed with an external 5 V for optimum efficiency and Programmable input UVLO threshold used to drive external N-channel MOSFETs or other loads. Independent enable pin for switcher and LDO Additional features include cycle-by-cycle current limit, Selectable ultra-sonic power-save mode voltage soft-start, under-voltage protection, programmable over-current protection, soft shutdown and selectable Internal soft-start and soft-shutdown power-save. The Vishay Siliconix SiC417 also provides an 1 % internal reference voltage enable input and a power good output. Power good output and over voltage protection Halogen-free according to IEC 61249-2-21 definition Compliant to RoHS directive 2002/95/EC PRODUCT SUMMARY Input Voltage Range 3 V to 28 V APPLICATIONS Output Voltage Range 0.5 V to 5.5 V Notebook, desktop and server computers Operating Frequency 200 kHz to 1 MHz Digital HDTV and digital consumer applications Continuous Output Current 10 A Networking and telecommunication equipment Peak Efficiency 95 % at 300 kHz Printers, DSL and STB applications Package MLPQ 5 mm x 5 mm Embedded applications Point of load power supplies TYPICAL APPLICATION CIRCUIT 12 DH V V5V IN 6 3 BST V LDO 7 8 FBL 2 LX 13 EN/PSV PWM EN-P 29 SAVE Controller P GOOD P 26 27 GOOD I LIM ENL EN-LDO 32 15 P GND t ON 5 31 A FB DL V GND OUT 30 1 14 Document Number: 69062 www.vishay.com S10-1367-Rev. D, 14-Jun-10 1SiC417 Vishay Siliconix PIN CONFIGURATION FB LX PAD 1 FBL LX A 34 GND P V5V GND A PAD 3 P GND GND VOUT LX 33 P GND PAD 2 V IN PGND V 35 IN V P LDO GND BST P GND PIN DESCRIPTION Pin Number Symbol Description Feedback input for switching regulator. Connect to an external resistor divider from output to program the 1FB output voltage. 2 FBL Feedback input for the LDO. Connect to an external resistor divider from V to program the V output. LDO LDO 5 V power input for internal analog circuits and gate drives. Connect to external 5 V supply or configure the 3V5V LDO for 5 V and connect to V . LDO 4, 30, PAD 1 A Analog ground. GND 5V Output voltage input to the SiC417. Additionally, may be used to bypass LDO to supply V directly. OUT LDO 6, 9 - 11, PAD 2 V Input supply voltage. IN 7V LDO output. LDO Bootstrap pin. A capacitor is connected between BST to LX to develop the floating voltage for the high-side 8BST gate drive. 12 DH High-side gate drive - do not connect this pin. 14 DL Low-side gate drive - do not connect this pin. 13, 23 - 25, 28, LX Switching (Phase) node. PAD 3 15-22 P Power ground. GND Open-drain power good indicator. High impedance indicates power is good. An external pull-up resistor is 26 P GOOD required. 27 I Current limit sense point - to program the current limit connect a resistor from I to LX. LIM LIM Tri-state pin. Enable input for switching regulator. Connect EN to A to disable the switching regulator. GND 29 EN/PSV Float pin for forced continuous and pull high for power-save mode. 31 t On-time set input. Set the on-time by a series resistor to the input supply voltage. ON 32 ENL Enable input for the LDO. Connect ENL to A to disable the LDO. GND ORDERING INFORMATION Part Number Package SiC417CD-T1-E3 MLPQ55-32 SiC417DB Evaluation board www.vishay.com Document Number: 69062 2 S10-1367-Rev. D, 14-Jun-10 V IN ENL V IN t ON V A IN GND DH EN/PSV LX LX DL I LIM P P GND GOOD P LX GND