5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER WITH DUAL CONTROLLER FE
|
|
|
Top Searches for this datasheet
IRU3004, IRU3005
5-BIT PROGRAMMABLE SYNCHRONOUS BUCK CONTROLLER WITH DUAL CONTROLLER FEATURES
Meets latest specification PIII Provides single chip solution Vcore, GTL+ clock supply On-board programs output voltage from 1.3V 3.5V. IRU3004/IRU3005 remains code (11111). Dual linear regulator controller on-board 1.5V GTL+ 2.5V clock supplies Loss-less short circuit protection Synchronous operation allows maximum efficiency Patented architecture allows fixed frequency operation well 100% duty cycle during dynamic load Minimum part count. external compensation. Soft start High current totem pole driver direct driving external power MOSFET Power Good function
IRU3004/IRU3005 series controller specifically designed meet Intel specifications Pentium IIImicroprocessor applications well next generation family processors. provides single chip controller Vcore, GTL+ clock supplies required Pentium applications. These devices feature patented topology, that combination with external components shown typical application circuit, will provide excess output current on-board DC-DC converter while automatically providing right output voltage five-bit internal meeting latest specification. These products also feature loss-lesscurrent sensing using RDS(on) high side power MOSFET sensing resistor Power Good window comparator that switches open collector output when output outside ±10% window. Other features device are: Undervoltage lockout both supplies, external programmable soft start function well programming oscillator frequency using external capacitor.
APPLICATIONS
Pentium next generation processor converter application cost Pentium with
TYPICAL APPLICATION
Vout
3.3V
Vfb2 HDrv CS11 LDrv Vfb3 Lin1 Vfb1 Lin2
3004app2-2.0
Vout
IRU3004
Vout
VID4 VID3 VID2 VID1 VID0
3.3V
Power Good
Notes: Pentium trademark Intel Corp.
PACKAGE ORDER INFORMATION
(°C) Device IRU3004CW IRU3005CW Package 20-pin Plastic SOIC 20-pin Plastic SOIC 2.5V Output Voltage Adjustable Fixed
Rev. 12/8/00
IRU3004, IRU3005
ABSOLUTE MAXIMUM RATINGS
supply Voltage Supply Voltage Storage Temperature Range Operating Junction Temperature Range 150° 125°
PACKAGE INFORMATION
20-PIN WIDE BODY PLASTIC SOIC
VIEW
Lin1 Vfb1 Vfb2 HDrv
Lin2 Vfb3 LDrv
=85°C/W
ELECTRICAL SPECIFICATIONS
Unless otherwise specified, these specifications apply over,V12 12V, Ta=0 Typical values refer =25° duty cycle pulse testing used which keeps junction case temperatures equal ambient temperature. PARAMETER Section output voltage (note Output Line Regulation Output Temp Variation Input Input input internal pull-up resistor Power Good Section Under voltage lower trip point Under voltage upper trip point Hysterises Over voltage upper trip point Over voltage lower trip point Hysterises Power Good Output Power Good Output Soft Start Section Soft Start Current TEST CONDITION 0.99Vs 1.01Vs UNITS
Vout ramping down Vout ramping Vout ramping Vout ramping down RL=3mA RL=5K pull =0V,
0.89Vs .015Vs 1.09Vs .015Vs
0.90Vs 0.92Vs .02Vs 1.10Vs 1.08Vs .02Vs
0.91Vs .025Vs 1.11Vs .025Vs
Rev. 12/8/00
IRU3004, IRU3005
PARAMETER UVLO Section UVLO Threshold-12V UVLO Hysterises-12V UVLO Threshold-5V UVLO Hysterises-5V Error Comparator Section Input bias current Input Offset Voltage Delay Output Current Limit Section Threshold Current Comp Offset Voltage Hiccup Duty Cycle Supply Current Operating Supply Current TEST CONDITION Supply ramping Supply ramping 10.8 UNITS
Vdiff=10mV Css=0.1µF CL=3000pF CL=3000pF CL=3000pF CL=3000pF Ct=150pF
1.477 1.500 2.500 1.522
Output Drivers Section Rise Time Fall Time Dead Band Time Oscillator Section Frequency Valley Peak Controller Section Vfb1 Vfb2 (IRU3004) Vfb2 (IRU3005) Vfb1 (IRU3005) Input bias current Lin1 Lin2 Drive Current
Note refers point voltage given Table
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
Table point voltage codes
Rev. 12/8/00
IRU3004, IRU3005
DESCRIPTIONS
PIN# SYMBOL DESCRIPTION input that programs output voltage. This pulled externally resistor either 3.3V supply. Input that programs output voltage. This pulled externally resistor either 3.3V supply. Input that programs output voltage. This pulled externally resistor either 3.3V supply. input that programs output voltage. This pulled externally resistor either 3.3V supply. This selects range output voltages DAC. When state range 1.3V 2.05V. codes IRU3004 keeps outputs This open collector output that switches when output converter within ±10% (typ) nominal output voltage. When PWRGD switches voltage less than 0.4V 3mA. This connected directly output Core supply provide feedback Error comparator. This connected Drain power MOSFET Core supply provides positive sensing internal current sensing circuitry. external resis programs threshold depending power MOSFET. external capacitor placed parallel with programming resistor provide high frequency noise filtering. This connected Source power MOSFET Core supply provides negative sensing internal current sensing circuitry. This provides soft start switching regulator. internal current source charges external capacitor that connected from this which ramps outputs switching regulator, preventing outputs from overshooting well limiting input current. second function Soft Start provide long time (HICCUP) synchronous MOSFET during current limiting. This programs oscillator frequency range 50kHZ 500kHZ with external capacitor connected from this GND. This controls gate external transistor either GTL+ linear regulator Clock supply. This provides feedback linear regulator that output drive Lin1 pin. IRU3005, this connected 2.5V regulator, eliminating external dividers. This controls gate external transistor either GTL+ linear regulator Clock supply. This provides feedback linear regulator that output drive Lin2 pin. This serves ground must connected directly ground plane. high frequency capacitor (0.1 1µF) must connected from pins this noise free operation. Output driver synchronous power MOSFET. Output driver high-side power MOSFET. This connected supply serves power output drivers. high frequency capacitor (0.1 1µF) must connected directly from this order supply peak current power MOSFET during transi tions. supply voltage.
Rev. 12/8/00
Vfb3
CSSS
Lin1 Vfb1 Lin2 Vfb2
LDrv HDrv
IRU3004, IRU3005
BLOCK DIAGRAM
Vfb3
Enable Vset Enable
UVLO
Vset
HDrv Control
Vfb2 5Bit DAC, Ctrl Logic
Enable
Slope Comp
LDrv
Soft Start Fault Logic
Over Current
200uA
Enable
Lin2
1.1Vset
1.5V
Lin1
0.9Vset
Vfb1
3004blk2-1.3
Figure Simplified block diagram IRU3004
Rev. 12/8/00
IRU3004, IRU3005
TYPICAL APPLICATION
Pentium
Vout
3.3V
Vfb2 HDrv CS11 LDrv Vfb3 Lin1 Vfb1 Lin2
Vout
IRU3004
Vout
VID4 VID3 VID2 VID1 VID0
3004app2-2.0
3.3V
Power Good
Figure Typical application IRU3004 IRU3005 on-board DC-DC converter providing Core, GTL+, Clock supplies Pentium microprocessor Part IRU3004 IRU3005 Value Parts List Short Value Parts List Open
Table Describes differences between IRU3004 IRU3005 applications
Rev. 12/8/00
IRU3004, IRU3005
IRU3004/IRU3005 Application Parts List Design Description MOSFET MOSFET Bipolar Trans, MOSFET Inductor Inductor Capacitor, Ceramic Capacitor, Ceramic Capacitor, Electrolytic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Ceramic Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Part IRL3103S, TO-263 package IRL3103D1S, TO-263 package MPS2222A, SOT-23 package IRLR024, TO-252 package L=1µH, 5052 core with turns 1.0mm wire L=2.7µH, 5052B core with turns 1.2mm wire 150pF, 0603 1uF, 0603 10MV1200GX, 1200µF,10V 1µF, 0805 220pF, 0603 1000pF, 0603 0.1µF, 0603 6MV1000GX, 1000µF, 6.3V 6MV1500GX, 1500µF, 6.3V 6MV150GX, 150µF, 6.3V 6MV1000GX, 1000µF, 6.3V 10MV470GX, 470µF, 4.7µF, 1206 3.3k, 0603 4.7, 1206 10k, 0603 100, 0603 150, 0603 100, 0603 22k, 0603 220, 0603 330, 0603 0603 Sanyo Sanyo Sanyo Sanyo Sanyo Sanyo Manuf Motorola MicroMetal Micro Metal
Capacitor, Ceramic
Resistor
Note R16, R17, C16, R12, Vcore higher level shift reduce transient voltage Note 1.5V approximately higher account trace resistance drop
Rev. 12/8/00
IRU3004, IRU3005
TYPICAL APPLICATION
Pentium with
Vout
3.3V
Vfb2 HDrv CS11 LDrv Vfb3 Lin1 Vfb1 Lin2 3.3V
3004app3-1.4
IRU3004
3.3V
VID4 VID3 VID2 VID1 VID0
Power Good
Figure Typical application IRU3004 Pentium with where power dissipation 3.3V linear regulator equally distributed between pass transistors. This equal distribution possible accurately regulating first regulator using IRU3004 linear controller internal reference voltage while second controller regulates output first regulator from 4.17V 3.3V, thereby distributing power dissipation equally.
4-10
Rev. 12/8/00
IRU3004, IRU3005
IRU3004 Application Parts List Desig Description MOSFET Q3,4 C2,6 C7,14,15 R2,3,4 R5,15 R9,11,14 MOSFET MOSFET Inductor Inductor Capacitor, Ceramic Capacitor, Ceramic Capacitor, Electrolytic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Ceramic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Electrolytic Capacitor, Ceramic Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Resistor Part IRL3103s, TO-263 package IRL3103D1S, TO-263 package IRL3303S, TO-263 package L=1µH, 5052 core with turns 1.0mm wire L=2.7µH, 5052B core with turns 1.2mm wire 150pF, 0603 1µF, 0603 10MV1200GX, 1200µF,10V 1µF, 0805 220pF, 0603 1000pF, 0603 0.1µF, 0603 6MV1000GX, 1000µF, 6.3V 6MV1500GX, 1500µF, 6.3V 6MV150GX, 150µF, 6.3V 6MV1000GX, 1000µF, 6.3V 10MV470GX, 470µF, 4.7µF, 1206 3.3k, 0603 4.7, 1206 10k, 0603 267, 0603 150, 0603 100, 0603 100, 0603 22k, 0603 220, 0603 330, 0603 0603 Sanyo Sanyo Sanyo Sanyo Sanyo Sanyo Micro Metal Manuf Micro Metal
Note R16, R17, C16, R12, Vcore higher level shift reduce transient voltage
Rev. 12/8/00
4-11
IRU3004, IRU3005
APPLICATION INFORMATION
example calculate components application circuit given below. Assuming, sets output conditions that this regulator must meet, Vo=2.8V, Io=14.2A, Vo=185mV, Io=14.2A Vo=2V, Io=14.2A, Vo=140mV, Io=14.2A regulator design will done such that meets worst case requirement each condition. Output Capacitor Selection first step select output capacitor. This done primarily selecting maximum value that meets transient voltage budget total specification. Assuming that regulators initial accuracy plus output ripple output voltage, then maximum output capacitor calculated 14.2 shifting during load transient eases requirement output capacitor cost load regulation. show that requirement eases half total trace resistance. example, requirement output capacitors without voltage level shifting must then after level shifting will only need 9.5m trace resistance (7+5/2=9.5). However, must careful that combined "voltage level shifting" transient response still within maximum tolerance Intel specification. insure this, maximum trace resistance must less than: 2(Vspec 0.02*Vo Vo)/I Where Rs=Total maximum trace resistance allowed Vspec=Intel total voltage spec Vo=Output voltage Vo=Output ripple voltage I=load current step example, assuming: Vspec=±140 mV=±0.1V output Vo=2V Vo=assume 10mV=0.01V I=14.2A Then calculated 2(0.140 0.02*2 0.01)/14.2=12.6m However, resistor this value used, maximum power dissipated trace external resistor being used) must also considered. example Rs=12.6m, power dissipated (Io^2)*Rs=(14.2^2)*12.6=2.54W. This power dissipated system. Rs=5m, then power dissipated about which much more acceptable. level shifting implemented, then maximum output capacitor shown previously which translated 1500µF, 6MV1500GX type Sanyo capacitors. With Rs=5m, maximum becomes 9.5m which equivalent caps. Another important consideration that trace being used implement resistor, power dissipated trace increases case temperature output capacitors which could seriously effect life time output capacitors. Output Inductor Selection output inductance must selected such that under line maximum output voltage condition, inductor current slope times output capacitor ramping faster than capacitor voltage
Rev. 12/8/00
Sanyo MVGX series good choice achieve both price performance goals. 6MV1500GX, 1500µF, 6.3V less than typical. Selecting these capacitors parallel which achieves goal. Other type Electrolytic capacitors from other manufacturers consider Panasonic series Nichicon series. Reducing Output Capacitors Using Voltage Level Shifting Technique trace resistance external resistor from output switching regulator Slot used circuit advantage possibly reduce number output capacitors, level shifting regulation point when transitioning from light load full load vice versa. accomplish this, output regulator typically about half drop that results from light load full load. example, total resistance from output capacitors Slot back device total change from light load full load 14A, then output voltage measured resistor divider which also connected output capacitors this case, must half 70mV 35mV higher than voltage setting. This intentional voltage level
4-12
IRU3004, IRU3005
drooping during load current step. However, inductor small, output ripple current ripple voltage become large. solution bring ripple current down increase switching frequency, however that will cost reduced efficiency higher system cost. following formulas derived achieve optimum performance without many design iterations. maximum output inductance calculated using following equation: Vinmin Vomax Where: Vinmin Minimum input voltage 14.2 =0.006 9000 4.75 2.8) 14.2) 3.7µH Assuming that programmed switching frequency 200KHZ, inductor designed using Micrometals' powder iron core material. summary design outlined below: selected core material Powder Iron, selected core T50-52D from Micro Metal wounded with turns wire, resulting inductance with resistance. Assuming switching frequency; 200KHZ inductor ripple current output ripple voltage calculated using following equations: 1/Fsw Switching Period Vsync Vsync Duty Cycle High side Mosfet Voltage Mosfet Resistance Toff Vsync Synchronous MOSFET Voltage=Io Vsync Toff Inductor Ripple Current Output Ripple Voltage example 2.8V 14.2 load, assuming IRL3103 MOSFET both switches with maximum onresistance 19m, have: 200000 5µSec =Vsync= 14.2*0.019=0.27 0.27 0.27 0.27 0.61 0.61 3.1µSec Toff 1.9µSec 0.27 1.94A 1.94 .006 .011 11mV Power Component Selection Assuming IRL3103 MOSFETs power components, will calculate maximum power dissipation follows: high-side switch maximum power dissipation happens maximum maximum duty cycle. Dmax 0.27 4.75 0.27 0.27 0.65 Dmax Io^2*RDS(max) Pdh= 0.65*14.2^2*0.029=3.8 RDS(max)=Maximum RDS(on) MOSFET 125°C synch MOSFET, maximum power dissipation happens minimum minimum duty cycle. Dmin 0.27 5.25 0.27 0.27 0.43 (1-Dmin)*Io^2*RDS(max) Pds=(1 0.43) 14.2^2 0.029 3.33 Heatsink Selection Selection heat sink based maximum allowable junction temperature MOSFETS. Since previously selected maximum RDS(on) 125°C, then must keep junction below this temperature. Selecting TO-220 package gives jc=1.8°C/W (from venders' datasheet assuming that selected heatsink black anodized, heat-sink-to-case thermal resistance cs=0.05°C/W, maximum heat sink temperature then calculated 3.82 (1.8 0.05) With maximum heat sink temperature calculated previous step, heat-sink-to-air thermal resistance (sa) calculated follows: Assuming Ta=35 Temperature Rise Above Ambient T/Pd 3.82 °C/W Next, heat sink with lower than calculated previous step must selected. this simply look graphs "Heat Sink Temp Rise Above Ambient" "Power Dissipation" given heatsink manufacturers' catalog select heat sink that results lower temperature rise than calculated previous step. following heat sinks from AAVID Thermalloy meet this criteria. Part Thermalloy 6078B AAVID 577002
Rev. 12/8/00
4-13
IRU3004, IRU3005
Following same procedure Schottky diode results heatsink with °C/W. Although possible select slightly smaller heatsink, simplicity same heatsink high side MOSFET also selected synchronous MOSFET. Switcher Current Limit Protection controller uses MOSFET RDS(on) sensing resistor sense MOSFET current compares programmed voltage which externally resistor (Rcs) placed between drain MOSFET "CS+" terminal shown application circuit. example, desired current limit point from previous selection, maximum MOSFET RDS(on)=19m, then current sense resistor, calculated Vcs=IcL*Rds=22*0.019=0.418V Where: Ib=200µA internal current setting device Switcher Timing Capacitor Selection switching frequency programmed using external timing capacitor. value approximated using equation below: With maximum heat sink temperature calculated previous step, heat-sink-to-air thermal resistance (sa) calculated follows: Assuming Ta=35 Temperature Rise Above Ambient T/Pd °C/W same heat sink selected switcher MOSFETs also suitable 1.5V regulator. also possible TO-263 package even MTD3055VL D-Pak load current less than 1.5A. 2.5V regulator since dropout voltage only 0.8V load current less than 0.5A, most applications same MOSFET without heat sink cost applications, PN2222A TO-92 SOT-23 package. Regulator Component Selection first step selecting power MOSFET linear regulators select maximum RDS(on) based input output Dropout voltage maximum load current. RDS(max) 1.5V, 3.3V IL=2A RDS(max) (3.3 1.5)/2= Since internal voltage reference linear regulators 1.5V devices, there need divide output voltage 1.5V, GTL+ regulator. Note that since MOSFETs RDS(on) increases with temperature, this number must divided 1.5, order find RDS(on) room temperature. Motorola MTP3055VL maximum 0.18 RDS(on) room temperature, which meets requirement. select heatsink MOSFET first step calculate maximum power dissipation device then follow same procedure switcher. Where Power Dissipation Linear Regulator Linear Regulator Load Current 1.5V load: (3.3 1.5)*2=3.6 Assuming Tj-max=125°C (1.8 0.05)
Where: Where
Timing Capacitor Switching Frequency 200kHz:
Power MOSFET Selection
4-14
Rev. 12/8/00
IRU3004, IRU3005
2.5V, Clock supply resistor dividers selected following: Vo=(1+Rt/Rb)*Vref Where: Rt=Top resistor divider Rb=Bottom resistor divider Vref=1.5V typical Assuming Rt=100, Vo=2.5V Rb=Rt [(Vo/Vref) Rb=100 [(2.5/1.5) 1]=150 1.5V output, shorted left open. However, recommended leave resistor dividers shown typical application circuit that output voltage adjusted higher account trace resistance final board layout. also recommended that external filter added linear regulators reduce amount high frequency ripple output regulators. This simply done resistor capacitor combination shown application circuit. IRU3005 that includes resistor dividers internally, Vfb1 directly connected output voltage without external resistors preset voltage 2.5V. disadvantage that output voltage adjustable anymore. application circuit given Pentium either IRU3004 IRU3005 family parts maximum flexibility. Disabling Regulators controllers easily disabled connecting feedback pins, Vfb1 Vfb2 voltage higher than 2.5V such devices. Switcher Output Voltage Adjust discussed earlier, trace resistance from output switching regulator Slot used circuit advantage possibly reduce number output capacitors, level shifting regulation point when transitioning from light load full load vice versa. account drop, output regulator typically about half drop that results from light load full load. example, total resistance from output capacitors Slot back part total change from light load full load 14A, then output voltage measured resistor divider which also connected output capacitors this case, must half 35mV higher than voltage setting. this, resistor resistor divider (R12 application circuit) 100, calculated. example, voltage setting 2.8V desired output under light load 2.835V, then calculated using following formula: R13= 100*{Vdac /(Vo 1.004*Vdac)} R13= 100*{2.8 /(2.835 1.004*2.800)} 11.76 Select 11.8 Note: value resistor must exceed 100. bottom resistor then adjusted raise output voltage. Soft Start Capacitor Selection soft start capacitor must selected such that during start when output capacitors charging peak inductor current does reach current limit threshold. minimum capacitor insures this most applications. internal 10µA current source charges soft start capacitor which slowly ramps inverting input comparator Vfb3. This insures output voltage ramp same rate soft start thereby limiting input current. example, with 10µA internal current source ramp rate t)=I/C 1V/100mS. Assuming that output capacitance 9000µF, maximum start current will I=9000µF*(1V/100mS)=0.09A Input Filter highly recommended place inductor between system supply input capacitors switching regulator isolate supply from switching noise that occurs during turn switching components. Typically inductor range will sufficient this type application. Switcher External Shutdown best shutdown switcher pull down soft start using external small signal transistor such 2N3904 2N7002 small signal MOSFET. This allows slow ramp output, same power
Rev. 12/8/00
4-15
IRU3004, IRU3005
Layout Considerations Switching regulators require careful attention layout components, specifically power components since they switch large currents. These switching components create large amount voltage spikes high frequency harmonics some critical components away from each other connected with inductive traces. following guideline place critical components connections between them order minimize above issues. Start layout first placing power components: Place input capacitors high side MOSFET, close each other possible Place synchronous MOSFET, close each other possible with intention that source drain shortest length. Place snubber between Place output inductor, output capacitors, between MOSFET load with output capacitors distributed along slot close Place bypass capacitors, right next pins. next 12V, next Place controller such that output drives, pins relatively short distance from gates Place resistor dividers, close (note close (note close Note Although, controller does require R12-15 resistors, feedback pins directly connected their respective outputs, they used outputs slightly higher account output drop load trace resistance. critical, place high frequency ceramic capacitors close clock chip termination resistors provide local bypassing. Place timing capacitor close soft start capacitor close Component connections: Note: extremely important that data should passing through switching regulator section specifically close fast transition nodes such drives inductor voltage. Using layer board, dedicate layer GND, another layer power layer 3.3V, Vcore, 1.5V possible 2.5V. Connect grounds ground plane using direct vias ground plane. large inductance/low impedance plane connect following connections either using component side solder side. Drain Source Drain drain output capacitors, slot Input filter drain source Connect rest components using shortest connection possible. Place R11, C15, close each other same with C14, C12. Note: better place linear regulator components close then trace from output each regulator respective load such 2.5V clock 1.5V termination. However, this possible then trace from linear drive output pins, pins must routed away from high frequency data signals.
4-16
Rev. 12/8/00
Other recent searches
NJM2865 - NJM2865 NJM2865 Datasheet
NJM2865F3 - NJM2865F3 NJM2865F3 Datasheet
GR1089 - GR1089 GR1089 Datasheet
UL60950 - UL60950 UL60950 Datasheet
CXG1053FN - CXG1053FN CXG1053FN Datasheet
B41820 - B41820 B41820 Datasheet
ADE7763 - ADE7763 ADE7763 Datasheet
IEC62053-21 - IEC62053-21 IEC62053-21 Datasheet
IEC62053-22 - IEC62053-22 IEC62053-22 Datasheet
Privacy Policy | Disclaimer
© 2012 Datasheet Archive
