US3021B 5 BIT PROGRAMMABLE SYNCHRONOUS BUCK PLUS TRIPPLE LDO CONTROLLER PRELIMINARY DATASHEET FEATURES DESCRIPTION Provides Single Chip Solution for Vcore, GTL+ ,AGP Bus, and 1.8V Automatic Voltage Selection for AGP slot Vddq supply Linear regulator controller on board for 1.8V Designed to meet Intel Latest VRM specification for next generation micrprocessors 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 for all outputs Synchronous operation allows maximum efficiency Patented architecture allows fixed frequency operation as well as 100% duty cycle during dynamic load Minimum part count 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 output APPLICATIONS Total Power Soloution for Next Generation Intel Processor application The US3021B controller IC is specifically designed to meet Intel specification for next generation microprocessor applications requiring multiple on board regulators . The US3021B provides a single chip controller IC for the Vcore , 3LDO controllers, one with the automatic select pin that connects to the TYPE DETECT pin of the AGP slot for the AGP Vddq supply, one for GTL+ and the other for the 1.8V chip set regulator as required for the next generation PC applications. The US3021B typically uses Bipolar transistors for Vout3(1.5V) and Vout4(1.8V) however if Vaux pin is connected to 12V, then MOSFETs can also be used as external pass elements. No external resistor divider is necessary for any of the regulators. The switching regulator feature a patented topology that in combination with a few external components as shown in the typical application circuit ,will provide well in excess of 20A of output current for an on- board DC/DC converter while automatically providing the right output voltage via the 5 bit internal DAC .The US3021B also features, loss less current sensing for both switcher by using the Rds-on of the high side Power MOSFET as the sensing resistor, an output under voltage shutdown that detects short circuit condition for the linear outputs and latches the system off, and 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. TYPICAL APPLICATION 5V 3.3V LINEAR CONTROL Vout2 SWITCHER CONTROL Vout1 US3021B LINEAR CONTROL LINEAR CONTROL Vout3 Vout4 3021Bapp3-1.1 PACKAGE ORDER INFORMATION Ta (°C) 0 TO 70 Rev. 1.4 12/8/00 Device US3021BCW Package 28 pin Plastic SOIC WB 4-1 US3021B 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 28 PIN WIDE BODY PLASTIC SOIC (W) TOP VIEW Drive2 1 28 V12 Fix 2 27 UGate VID4 3 26 Phase VID3 4 25 LGate VID2 5 24 PGnd VID1 6 23 OCSet VID0 7 22 Vsen1 PGood 8 21 Fb SD 9 20 V5 Vsen2 10 19 Vsen3 Select 11 18 Drive3 SS 12 Fault / Rt 13 Vsen4 14 17 Gnd 16 Vaux 15 Drive4 θJA =80°C/W ELECTRICAL SPECIFICATIONS 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 0.6 V UVLO Threshold-5V Supply ramping up 4.4 V UVLO Hysterises-5V 0.3 V Supply Current Operating Supply Current V12 6 mA V5 30 Switching Controllers; Vcore (Vsen 1) and AGP (Vsen 2) VID Section (Vcore only) DAC output voltage (note 1) 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 resistor to V5 27 kΩ Vsen2 Voltage Select<0.8V 1.5 V Select>2V 3.3 V 4-2 Rev. 1.4 12/8/00 US3021B Error Comparator Section Input bias current Input Offset Voltage Delay to Output Current Limit Section C.S Threshold Set Current C.S Comp Offset Voltage Hiccup Duty Cycle Output Drivers Section Rise Time Fall Time Dead band Time Between High side and Synch Drive (Vcore Switcher Only) Oscillator Section (internal) Osc Frequency 1.8V Regulator (Vsen 4) Vsense Voltage Vo4 Vsense Voltage Input bias current Output Drive Current 1.5V Regulator (Vsen 3) Vsense Voltage Vsense Voltage Input bias current Output Drive Current Power Good Section Vsen1 UV lower trip point Vsen1 UV upper trip point Vsen1 UV Hysterises Vsen1 HV upper trip point Vsen1 HV lower trip point Vsen1 HV Hysterises Vsen2 trip point Vsen4 trip point Vsen3 trip point Power Good Output LO Power Good Output HI Fault (Overvoltage) Section Core O.V. upper trip point Core O.V. lower trip point FAULT Output HI Soft Start Section Soft Start Current Rev. 1.4 12/8/00 Vo3 -2 Vdiff=10mV 2 +2 100 uA mV nS +5 200 Css=0.1 uF 10 uA mV % CL=3000pF CL=3000pF 70 70 nS nS CL=3000pF 200 nS Rt=Open 217 Khz Ta=25, Drive4 = Vsen4 1.800 1.800 V V uA mA -5 2 Vaux-Vdrive>0.6V 50 Ta=25, Drive3 = Vsen3 1.500 1.500 2 Vaux-Vdrive>0.6V Vsen1 ramping down Vsen1 ramping up 50 V V uA mA Select<0.8V Select>2V Fix=GND Fix=Open Fix=GND Fix=Open RL=3mA RL=5K pull up to 5V 0.90Vs 0.92Vs .02Vs 1.10Vs 1.08Vs .02Vs 1.100 2.560 0.920 1.320 0.920 1.140 0.4 4.8 V V V V V V V V V V V V V V Vsen1 ramping up Vsen1 ramping down Io=3mA 1.17Vs 1.15Vs 10 V V V OCset=0V , Phase=5V 20 uA Vsen1 ramping up Vsen1 ramping down 4-3 US3021B Note 1: Vs refers to the set point voltage given in Table 1. D4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 D3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 D2 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 D1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 D0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 Vs 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75 1.80 1.85 1.90 1.95 2.00 2.05 D4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D3 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 D2 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 D1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 D0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 Vs 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 Table 1 - Set point voltage vs. VID codes PIN DESCRIPTIONS PIN# PIN SYMBOL 7 VID0 6 VID1 5 VID2 4 VID3 3 VID4 8 PGOOD 21 FB 1 9 Drive2 SD 4-4 Pin Description LSB input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by a 27kΩ resistor to 5V supply. Input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by a 27kΩ resistor to 5V supply. Input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by a 27kΩ resistor to 5V supply. MSB input to the DAC that programs the output voltage. This pin is TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by a 27kΩ resistor to 5V supply. This pin selects a range of output voltages for the DAC.When in the LOW state the range is 1.3V to 2.05V and when it switches to HI state the range is 2.0V to 3.5V. This pin is TTL compatible that realizes a logic “1” as either HI or Open. When left open,his pin is pulled up internally by a 27kΩ resistor to 5V supply. This pin is an open collector output that switches LO when any of the outputs are outside of the specified under voltage trip point. It also switches low when Vsen1 pin is more than 10% above the DAC voltage setting. This pin provides the feedback for the synchronous switching regulator. Typically this pin can be connected directly to the output of the switching regulator. However, a resistor divider is recommended to be connected from this pin to vout1 and GND to adjust the output voltage for any drop in the output voltage that is caused by the trace resistance. The value of the resistor connected from Vout1 to FB1 must be less than 1000Ω. This pin controls the gate of an external MOSFET for the AGP linear regulator. This pin provides shutdown for all the regulatos. A TTL compatible, logic level high applied to this pin disables all the outputs and discharges the soft start capacitor. The SD signal turns off the synchronous allowing body diode to conduct and discharge the output cap. Rev. 1.4 12/8/00 US3021B PIN# PIN SYMBOL 22 Vsen1 10 Vsen2 15 23 Drive4 OCSET 26 PHASE 12 SS 13 FAULT/Rt 18 19 16 Drive3 Vsen3 Vaux 14 17 24 Vsen4 GND PGND 25 27 28 LGATE UGATE V12 20 V5 11 Select 2 FIX Rev. 1.4 12/8/00 Pin Description This pin is internally connected to the undervoltage and overvoltage comparators sensing the Vcore status. It must be connected directly to the Vcore supply. This pin provides the feedback for the AGP linear regulator. The Select pin when connected to the "Type Detect" pin of the AGP slot automatically selects the right voltage for the AGP Vddq. This pin controls the gate of an external MOSFET for the 1.8V chip set linear regulator. This pin is connected to the Drain of the power MOSFET of the Core supply and it provides the positive sensing for the internal current sensing circuitry. An external resistor programs the C.S threshold depending on the Rds of the power MOSFET. An external capacitor is placed in parallel with the programming resistor to provide high frequency noise filtering. This pin is connected to the Source of the power MOSFET for the Core supply and it provides the negative sensing for the internal current sensing circuitry. This pin provides the soft start for all the regulators. An internal current source charges an external capacitor that is connected from this pin to GND which ramps up the outputs of the regulators, preventing the outputs from overshooting as well as limiting the input current. The second function of the Soft Start cap is to provide long off time (HICCUP) for the synchronous MOSFET during current limiting. This pin has dual function. It acts as an output of the OVP circuitry or it can be used to program the frequency using an external resistor . When used as a fault detector, if any of the switcher outputs exceed the OVP trip point, the FAULT pin switches to 12V and the soft start cap is discharged. If the FAULT pin is to be connected to any external circuitry, it needs to be buffered. This pin controls the gate of an external transistor for the 1.5V GTL+ linear regulator. This pin provides the feedback for the linear regulator that its output drive is Drive3. This pin is normally connected to 3.3V or 5V input. When connected to the 12V supply, it provides gate drive voltage for the # 3 and #4 (Drive 3 and 4) linear regulator's pass transistors in case MOSFET transistors are being used instead of Bipolars. This pin provides the feedback for the linear regulator that its output drive is Drive4. This pin serves as the ground pin and must be connected directly to the ground plane. This pin serves as the Power ground pin and must be connected directly to the GND plane close to the source of the synchronous MOSFET. A high frequency capacitor (typically 1 uF) must be connected from V12 pin to this pin for noise free operation. Output driver for the synchronous power MOSFET for the Core supply. Output driver for the high side power MOSFET for the Core supply. This pin is connected to the 12 V supply and serves as the power Vcc pin for the output drivers. A high frequency capacitor (typically 1 uF) must be placed close to this pin and PGND pin and be connected directly from this pin to the GND plane for the noise free operation. 5V supply voltage. A high frequency capacitor (0.1 to 1 uF) must be placed close to this pin and connected from this pin to the GND plane for noise free operation. This pin provides automatic voltage selection for the AGP switching regulator. When it is pulled LO, the voltage is 1.5V and when left open or pulled to HI, the voltage is 3.3V. Leaving this pin open provides fixed output voltages of the 1.5V and 1.8V for the #3 and #4 linear regulators. When this pin is grounded the reference to the linear regulators are set to 1.26V and therefore the output of the regulators can be programmed to any voltages above the 1.26V using; Vout=1.26*(1+Rtop/Rbot) Where: Rtop=Top resistor connected from the output to the Vsense pin Rbot=Bottom resistor connected from the Vsense pin to ground. 4-5 US3021B BLOCK DIAGRAM V12 V5 SD Fb Enable UVLO 1.17Vset V12 Over Voltage Vsen1 PGood Vsen3 Vsen4 Vset UGate Enable PWM Control + 1.1Vset V12 Slope Comp LGate Osc Phase Fix 0.9Vset Vaux Drive4 Enable Soft Start & Fault Logic OCSet Over Current PGnd 200uA Gnd Fault / Rt R SS 1.26V 3R Vset Drive3 VID0 Select VID1 1.5V 3.3V R 5Bit DAC VID2 VID3 3R VID4 Drive2 Vsen2 3021Bblk1-1.4 Figure 1 - Simplified block diagram of the US3021. 4-6 Rev. 1.4 12/8/00 US3021B TYPICAL APPLICATION (Dual Layout with HIP6021) R1 12V L1 C5 5V C1 R2 C4 C3 C2 28 V12 23 OCSET 9 SD R4 Q1 UGATE 27 2 FIX L2 11 SELECT Type Detect PHASE 26 Vcore C7 R7 Q3 LGATE 25 R15 C22 R3 R14 R5 3.3Vin 16 Vaux R6 R10 PGND 24 VSEN1 22 C6 Q2 1 DRIVE2 FB 21 R9 Vout2 1.5V / 3.3V 10 VSEN2 U1 V5 20 (COMP) C13 C15 C16 C17 R8 C14 R11 R12 VID0 7 Q4 18 DRIVE3 VID1 6 VID2 5 19 VSEN3 Vout3 1.5V VID3 4 VID4 3 C18 Vcc3 R13 PGOOD 8 Q5 15 DRIVE4 FAULT/RT 13 VSEN4 GND 14 17 PGood C21 SS 12 3021Bapp2-1.0 Vout4 1.8V C20 C19 Figure 2 - Typical application of US3021B in a dual layout with HIP6021 for an on board DC-DC converter providing power for the Vcore , GTL+, 1.8V chip set supply as well as auto select AGP supply for the next generation PC applications. Part# HIP6021 US3021B R3 O O R5 S O S - Short O - Open R9 O O R10 V O R15 O S C15 O V C16 V O C17 V O V - See Unisem or Harris parts list for the value. Table 2 - Dual layout component table Note 1: If Q4 and Q5 are changed to MOSFETs such as IRLR024, then R2 is short and R4 is open. Rev. 1.4 12/8/00 4-7 US3021B US3021M Application Parts List Dual Layout with HIP6021 Ref Desig Q1 Q2 Q3 Q4,5 L1 Description MOSFET MOSFET MOSFET with Schottky Transistor Inductor Qty 1 1 1 2 1 L2 Inductor 1 C1 C2,3 C4 C5 C6,18 C7 C13,19 C14,15 C16,17 Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Ceramic Capacitor, Ceramic 1 2 1 1 2 6 1 2 2 C20,21 C22 R1 R2 R3,5,12 Capacitor, Ceramic Capacitor, Ceramic Resistor Resistor Resistor 2 1 1 1 3 R4,7,14 R6,8,10 R9 R11 R13 R15 Resistor Resistor Resistor Resistor Resistor Resistor 3 3 1 1 1 1 4-8 Part # IRL3103S, TO263 package IRLR3103, TO252 package IRL3103D1S, TO263 package 2SD1760, TO252 package L=1uH, 5052 core with 4 turns of 1.0mm wire L=2.7uH, 5052B core with 7 turns of 1.2mm wire 10MV470GX, 470uF,10V 10MV1200GX, 1200uF,10V 220pF, 0603 1uF, 0805 6MV1000GX, 1000uF,6.3V 6MV1500GX, 1500uF,6.3V, 6MV1500GX, 1500uF,6.3V, 1uF, 0603 See Table 2, dual layout component 0603 * 2 0.1uF, 0603 1000pF, 0603 10Ω, 5%, 0603 3.3kΩ, 5%, 0603 See Table 2, dual layout component 0603 * 3 4.7Ω, 5%, 1206 2.2kΩ, 1%, 0603 0Ω, 0603 220kΩ, 1%, 0603 10kΩ, 5%, 0603 0Ω, 0603 Manuf IR IR IR ROHM Micro Metal Micro Metal Sanyo Sanyo Sanyo Sanyo Sanyo Rev. 1.4 12/8/00