US3018

US3018 5 BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS LDO CONTROLLER AND 200mA LDO ON BOARD FEATURES Provides Single Chip Solution for Vcore, GTL+ & Clock Supply 200 mA On board LDO regulator Designed to meet the latest Intel specification for Pentium II™ On board DAC programs the output voltage from 1.3V to 3.5V Linear regulator controller on board for 1.5V GTL+ supply Loss less Short Circuit Protection with HICCUP Synchronous operation allows maximum efficiency Patented architecture allows fixed frequency operation as well as 100% duty cycle during dynamic load Soft Start High current totem pole driver for direct driving of the external Power MOSFET Power Good function Monitors all Outputs OVP Circuitry Protects the Switcher Output and generates a Fault signal Thermal Shutdown Logic Level Enable Input DESCRIPTION PRELIMINARY DATASHEET APPLICATIONS Total Power Soloution for Pentium II processor application The US3018 controller IC is specifically designed to meet Intel specification for Pentium II™ microprocessor applications as well as the next generation of P6 family processors. The US3018 provides a single chip controller IC for the Vcore , LDO controller for GTL+ and an internal 200mA regulator for clock supply which are required for the Pentium II applications. These devices feature a patented topology that in combination with a few external components as shown in the typical application circuit ,will provide in excess of 18A of output current for an on- board DC/DC converter while automatically providing the right output voltage via the 5 bit internal DAC. The US3018 also features, loss less current sensing for both switchers by using the Rds-on of the high side Power MOSFET as the sensing resistor, internal current limiting for the clock supply, a Power Good window comparator that switches its open collector output low when any one of the outputs is outside of a pre programmed window. Other features of the device are ; Undervoltage lockout for both 5V and 12V supplies, an external programmable soft start function , programming the oscillator frequency via an external resistor, OVP circuitry for both switcher outputs and an internal thermal shutdown. TYPICAL APPLICATION 5V US3018 SWITCHER1 CONTROL Vout1 3.3V LINEAR CONTROL LINEAR REGULATOR 3018app3-1.1 Vout2 Vout3 Notes: Pentium II is trade mark of Intel Corp. PACKAGE ORDER INFORMATION Ta (°C) 0 TO 70 Rev. 1.4 12/8/00 Device US3018CW Package 24 pin Plastic SOIC WB 4-1 US3018 ABSOLUTE MAXIMUM RATINGS V5 supply Voltage ........................................... 7V V12 Supply Voltage ............................................ 20V Storage Temperature Range ................................. -65 TO 150°C Operating Junction Temperature Range .......... 0 TO 125°C PACKAGE INFORMATION 24 PIN WIDE BODY PLASTIC SOIC (W) TOP VIEW V12 1 VID4 2 VID3 3 VID2 4 VID1 5 VID0 6 PGood 7 V5 8 SS 9 Fault / Rt 10 Fb2 11 Vin2 12 24 UGate1 23 Phase1 22 LGate1 21 PGnd 20 OCSet1 19 Vsen1 18 Fb1 17 En 16 Fb3 15 Gate3 14 Gnd 13 Vout2 θJA =80°C/W Unless otherwise specified ,these specifications apply over ,V12 = 12V, V5 = 5V and Ta=0 to 70°C. Typical values refer to Ta =25°C. Low duty cycle pulse testing are used which keeps junction and case temperatures equal to the ambient temperature. PARAMETER SYM TEST CONDITION MIN TYP MAX UNITS Supply UVLO Section UVLO Threshold-12V Supply ramping up 10 V UVLO Hysterises-12V 0.4 V UVLO Threshold-5V Supply ramping up 4.3 V UVLO Hysterises-5V 0.3 V Supply Current Operating Supply Current I12 V12 6 mA I5 V5 20 Switching Controller, Vcore (Vout 1) VID Section DAC output voltage (note 1) Vdac 0.99Vs Vs 1.01Vs V DAC Output Line Regulation 0.1 % DAC Output Temp Variation 0.5 % VID Input LO 0.8 V VID Input HI 2 V VID input internal pull-up 27 kΩ resistor to V5 ELECTRICAL SPECIFICATIONS 4-2 Rev. 1.4 12/8/00 US3018 Error Comparator Section Input bias current Input Offset Voltage Delay to Output Vdiff=10mV Current Limit Section C.S Threshold Set Current C.S Comp Offset Voltage Hiccup Duty Cycle Css=0.1 uF Output Drivers Section Rise Time CL=3000pF Fall Time CL=3000pF Dead band Time Between High side and Synch Drive Vcore Switcher Only CL=3000pF Oscillator Section (internal) Osc Frequency 2.5V Regulator (Vout 2) Reference Voltage Vo2 Ta=25, Vout2 = FB2 Reference Voltage Dropout Voltage Io = 200 mA Load Regulation 1mA< Io