Multi-Phase Controller Core Power Supply RT9245C multi-phase buck
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RT9245C
Multi-Phase Controller Core Power Supply
RT9245C multi-phase buck DC/DC controller integrated with control functions Intel which VRD10.x-compliant. RT9245C could operated with buck switching stages operating interleaved phase automatically. multiphase architecture provides high output current while maintaining power dissipation power devices stress input output capacitors. high equivalent operating frequency also reduces component dimension output voltage ripple load transient. RT9245C implements both voltage current loops achieve good regulation, response power stage thermal balance. RT9245C applies sensing technology newly. RT9245C extracts output inductor sense component deliver precise load line regulation good thermal balance next generation processor application. Current sense setting, droop tuning, VCORE initial offset over current protection independent compensation circuit voltage loop. feature greatly facilitates flexibility power supply design tuning. output RT9245C supports 5-bit Intel® VRD10.x with 6-bit input, precise offset value smooth VCORE transient jump. monitors VCORE voltage PGOOD over-voltage protection. Soft-start, over-current protection programmable under-voltage lockout also provided assure safety microprocessor power system. RT9245C comes small footprint package TSSOP-28.
Features
Multi-Phase Power Conversion with Automatic Phase Selection 6-bits VRD10.x 5-bit Output with Active Droop Compensation Fast Load Transient Smooth VCORE Transition Jump Power Stage Thermal Balance Current Sense Hiccup Mode Over-Current Protection Programmable Switching Frequency (50kHz 400kHz Phase), Under-Voltage Lockout SoftStart High Ripple Frequency Times Channel Number 28-TSSOP Package RoHS Compliant 100% Lead (Pb)-Free
Applications
Intel® Processors Voltage Regulator VRD10.x Output Voltage, High Current DC-DC Converters Voltage Regulator Modules
Configurations
(TOP VIEW)
VID4 VID3 VID2 VID1 VID0 VID125/VIDSEL SGND COMP PGOOD VOSS PWM1 PWM2 PWM3 PWM4 CSP4 CSP2 CSP3 CSP1 IOUT IMAX
Ordering Information
RT9245C Package Type TSSOP-28 Operating Temperature Range Free with Commercial Standard Green (Halogen Free with Commercial Standard)
TSSOP-28 Note RichTek Pb-free Green products RoHS compliant compatible with current requirements IPC/JEDEC J-STD-020. Suitable SnPb Pb-free soldering processes. 100% matte (Sn) plating. www.richtek.com
DS9245C-02 March 2007
1000uF 4.7uF 1000uF
1N4148 0.3uH IPD09N03LA IPD06N03LA 3.3nF RT9619 BOOT UGATE PHASE PGND LGATE 4.7uF 1000uF
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RT9245C
RT9245C
PHASE IPD06N03LA IPD09N03LA LGATE PGND 1N4148 4.7uF 0.3uH RT9619 BOOT UGATE 1N4148
1000uF 1000uF
Typical Application Circuit
VID125
VID125
PWM1 PWM2 PWM3 PWM4 CSP4 CSP2 CSP3 CSP1
/VIDSEL
VOUT
VID4
VID3
VID4
VID2
VID3
560uF
VID1
VID0
VID2 VID1
VID0
3.3nF 10uF
SGND
680pF
5.6pF
1.5k
COMP IOUT IMAX
6.8k BAT254 100k
1000uF 1000uF
Figure Intel
RT9619 BOOT UGATE PHASE LGATE PGND IPD09N03LA IPD06N03LA
2.7nF
3.3V
PGOOD
4.7uF
1.2k
68nF
0.3uH 3.3nF
100k
VOSS
1000uF 1000uF
1N4148 RT9619 BOOT UGATE PHASE LGATE PGND IPD09N03LA IPD06N03LA 3.3nF 4.7uF
DS9245C-02 March 2007
0.3uH
1000uF 4.7uF 1000uF
1N4148 IPD09N03LA IPD06N03LA 3.3nF RT9619 BOOT UGATE PHASE PGND
4.7uF
1000uF
DS9245C-02 March 2007
LGATE
RT9245C PWM1 PWM2 PWM3 PWM4 CSP4 CSP2 CSP3 CSP1 IOUT
100k 6.8k BAT254 1N4148 PGND LGATE IPD06N03LA PHASE IPD09N03LA RT9619 BOOT UGATE 1N4148 4.7uF
1000uF 1000uF
VID125
/VIDSEL
VOUT
VID4
VID3
VID4
VID2
VID3
1000uF
VID1
VID0
VID2 VID1
VID0
3.3nF 10uF
SGND
33pF
COMP
1000uF 1000uF
Figure
RT9619 BOOT UGATE PHASE LGATE PGND IPD09N03LA IPD06N03LA
10nF
3.3V/FSBVTT
4.7uF
PGOOD
IMAX
68nF
1.2k
VOSS
100k
3.3nF
1000uF 1000uF
1N4148 RT9619 BOOT UGATE PHASE LGATE PGND IPD09N03LA IPD06N03LA 3.3nF 4.7uF
RT9245C
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RT9245C
Functional Description
VID4 (Pin VID3 (Pin VID2 (Pin VID1 (Pin VID0 (Pin voltage identification inputs VRD10.x. These pins internally pulled 1.2V (VRD10.x) 2.1V (K8) left open. VID125/VIDSEL (Pin When this pull left ->VR10 input, pull high ->K8. SGND (Pin VCORE differential sense negative input. (Pin Inverting input internal error amplifier. COMP (Pin Output error amplifier input comparator. PGOOD (Pin Power good open-drain output. (Pin Programmable power UVLO detection input. Trip threshold 1.0V VDVD rising. (Pin Connect this with capacitor soft-start time interval. (Pin Switching frequency setting. Connect this with resistor frequency. VOSS (Pin VCORE initial value offset. Connect this with resistor negative offset value. Connect this positive offset value. PWM1 (Pin 27), PWM2 (Pin 26), PWM3 (Pin PWM4 (Pin outputs each driven channel. Connect these pins input MOSFET driver. systems which channels, connect PWM4 high. channel systems connect PWM3 high. (Pin power supply. Connect this supply. CSP1 (Pin 20), CSP2 (Pin 22), CSP3 (Pin CSP4 (Pin Current sense positive inputs individual converter channel current sense. (Pin Ground IMAX (Pin Programmable over currert setting. (Pin Current sense negative input channels. IOUT (Pin Output Current Indication Pin. current through IOUT proportional output current. (Pin Current sense output active droop adjust. Connect resistor from this load droop.
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DS9245C-02 March 2007
PWMCP
Setting Power Reset Logic Driver
Function Block Diagram
VID4 VID3 VID2 VID1 VID0 VID125 Trip Point
Oscillator Sawtooth
Droop
Trip Point
Current Correction
Amplifier
Control
SUM/M
VOSS COMP
IOUT
Offset Currrent Source/Sink
Error Amplifier
DS9245C-02 March 2007
IMAX PGOOD
Logic Driver
PWM1
PWM2
PWMCP Logic Driver PWM3
PWMCP
Logic Driver PWMCP Phase Control
PWM4
CSP1 CSP2 CSP3 CSP4
RT9245C
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RT9245C
Table Output Voltage Program (VRD 10.x)
Name ID125 Nominal Output oltage DACOUT 0.8375 0.8500 0.8625 0.8750 0.8875 0.9000 0.9125 0.9250 0.9375 0.9500 0.9625 0.9750 0.9875 1.0000 1.0125 1.0250 1.0375 1.0500 1.0625 1.0750 1.0875 1.1000 1.1125 1.1250 1.1375 1.1500 1.1625 1.1750 1.1875 1.2000 1.2125
continued
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RT9245C
Table Output Voltage Program (VRD 10.x)
Name ID125 Nominal Output oltage DACOUT 1.2250 1.2375 1.2500 1.2625 1.2750 1.2875 1.3000 1.3125 1.3250 1.3375 1.3500 1.3625 1.3750 1.3875 1.4000 1.4125 1.4250 1.4375 1.4500 1.4625 1.4750 1.4875 1.5000 1.5125 1.5250 1.5375 1.5500 1.5625 1.5750 1.5875 1.6000
Note: Connected Open Don't Care DS9245C-02 March 2007 www.richtek.com
RT9245C
Table Output Voltage Program (K8)
VID4 VID3 VID2 VID1 VID0 Nominal Output Voltage DACOUT 1.550 1.525 1.500 1.475 1.450 1.425 1.400 1.375 1.350 1.325 1.200 1.275 1.250 1.225 1.200 1.175 1.150 1.125 1.100 1.075 1.050 1.025 1.000 0.975 0.950 0.925 0.900 0.875 0.850 0.825 0.800 Shutdown
Note: Connected Open
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DS9245C-02 March 2007
RT9245C
Absolute Maximum Ratings
(Note 0.3V 0.3V 100°C/W 150°C 260°C -65°C 150°C 200V Supply Voltage, -Input, Output Voltage -Power Dissipation, 25°C TSSOP-28 -Package Thermal Resistance (Note TSSOP-28, -Junction Temperature -Lead Temperature (Soldering, sec.) -Storage Temperature Range -ESD Susceptibility (Note (Human Body Mode) (Machine Mode)
Recommended Operating Conditions
(Note
Supply Voltage, Junction Temperature Range -40°C 125°C Ambient Temperature Range -40°C 85°C
Electrical Characteristics
(VCC 25°C, unless otherwise specified)
Parameter Supply Current Nominal Supply Current Power-On Reset Threshold Hysteresis VDVD Threshold Oscillator Free Running Frequency Frequency Adjustable Range Ramp Amplitude Ramp Valley Maximum Duty Each Channel Voltage Reference DACOUT Voltage Accuracy VDAC VDAC VDAC -0.5 -+0.5 fOSC fOSC_ADJ VOSC -0.7 -1.9 Trip (Low High) Hysteresis VCCRTH VCCHYS VDVDTP VDVDHYS Enable Rising 0.94 -4.2 -1.06 1,2,3,4 Open Symbol Test Conditions Units
continued
DS9245C-02 March 2007 www.richtek.com
RT9245C
Parameter (VID0-VID125) Input Symbol VILDAC VIHDAC 10.x Test Conditions 10.x -0.8 10.x VVOSS RVOSS 100k -0.9 -3.5 -4.5 -1.1 Units
(VID0-VID125) Input High (VID0-VID125) pull resistor Pull Voltage VOSS Voltage Error Amplifier Gain Gain-Bandwidth Product Slew Rate Current Sense Amplifier Full Scale Source Current Current Protection Over-Voltage Trip (VFB VDAC) IMAX Voltage Power Good Output Voltage
-GBW COMP 10pF -100 VIMAX
-400
-450
IISPFSS
RADJ RIMAX
VPGOODL IPGOOD
Note Stresses listed above "Absolute Maximum Ratings" cause permanent damage device. These stress ratings. Functional operation device these other conditions beyond those indicated operational sections specifications implied. Exposure absolute maximum rating conditions extended periods remain possibility affect device reliability. Note Devices sensitive. Handling precaution recommended. Note device guaranteed function outside operating conditions. Note measured natural convection 25°C effective single layer thermal conductivity test board JEDEC 51-3 thermal measurement standard.
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DS9245C-02 March 2007
RT9245C
Typical Operating Characteristics
Adjustable Frequency
VCOMP
Duty Ratio
(kHz)
(kW)
VCOMP
Relationship Between Inductor Current VADJ
CH1:(5V/Div) CH2:(5V/Div)
Power-Off IOUT
CH1:(5V/Div) CH2:(20V/Div)
VADJ
UGATE
CH3:(10V/Div) CH4:(1V/Div)
LGATE
CH3:(50mV/Div) CH4:(20A/Div)
VCOMP Time (10s/Div)
Time (25ms/Div)
Power-On IOUT
CH1:(5V/Div) CH2:(5V/Div)
Ripple
CORE UGATE
CH3:(20V/Div) CH4:(10V/Div) (5mV/Div)
LGATE Time (10ms/Div)
0.3H, 5600F
Time (2.5s/Div)
DS9245C-02 March 2007
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RT9245C
DVID Rising DVID Falling
CORE
(500mV/Div)
(500mV/Div)
CORE
VID125
(2V/Div)
VID125
(2V/Div)
Time (50s/Div)
Time (50s/Div)
Transient Response
Transient Falling
(20mV/Div)
CORE CORE
(20mV/Div)
Time (5ms/Div)
Time (500ns/Div)
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DS9245C-02 March 2007
RT9245C
Application Information
RT9245C multi-phase DC/DC controller that precisely regulates core voltage balances current different power channels. converter consisting RT9245C companion MOSFET driver RT9619 provides high quality power protection functions meet requirement modern VRM. Voltage Control RT9245C senses VCORE SGND sense return minimize voltage drop trace heavy load. sensed pin. internal high accuracy provides reference voltage VRD10.x compliance. Control loop consists error amplifier, multi-phase pulse width modulator, driver power components. conventional voltage mode controller, output voltage locked VREF error amplifier error signal used control signal pulse width modulator. signals different channels generated comparison output split-phase sawtooth wave. Power stage transforms output signal on-time ratio. Current Balance RT9245C senses inductor current inductor's channel current balance droop tuning. differential sensing amplifier converts voltage sense component (can sense resistor inductor) current signal into internal balance circuit. current balance circuit sums averages current signals then produces balancing signals injected pulse width modulator. current some power channel larger than average, balancing signal reduces that channels pulse width keep current balance. single amplifier time sharing technique sense inductor currents reduce offset errors linearity variation between GMs. Thus greatly improve signal processing especially when dealing with such small signal voltage drop across DCR. Droop Load Line Setting RT9245C injects averaged current into resistor RADJ connected generate load-currentdependent voltage RADJ droop setting
DS9245C-02 March 2007
VADJ RADJ
VADJ then subtracted from VID_DAC output real reference voltage non-inverting input error amplifier shown Figure Consequently, load line slope calculated Load Line VCORE RADJ ICORE RCSN
where phase number operation.
IVOSS
VCORE
RCSN
VADJ
RADJ
Figure Load Line Offset Function Fault Detection chip detects over voltage power good detection. "hiccup mode" operation over current protection adopted reduce short circuit current. in-rush current start suppressed soft start circuit through clamping pulse width output voltage. Phase Setting Converter Start RT9245C interfaces with companion MOSFET drivers (like RT9619, RT9607 series) correct converter initialization. tri-state output (high, high impedance) senses interface voltage when acts (both trip). channel enabled voltage 1.2V less than VCC. corresponding current sense pins left float channel unused. example, 3-Channel application, connect PWM4 high. Current Sensing Setting RT9245C senses current flowing through inductor channel current balance droop tuning.
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RT9245C
differential sensing amplifier converts voltage sense component (can sense resistor inductor) current signal into internal circuit (see Figure Figure shows time sharing technique amplifier. apply test signal phase observe waveforms both pins amplifier. waveforms show time sharing mechanism perfomance hold both input pins equal when shared time
+VCR
Time Sharing
CH1:(2V/Div) CH2:(50mV/Div) CH3:(50mV/Div)
PWM3
RCSN
VCSP4
Figure Current Sense Circuit Figure test circuit apply test signal inputs observe signal process output pin. Figure shows variation signal processing channels. observe zero offsets good linearity between phases.
CSPX VADJ
VCSP4
Time (1s/Div)
Figure Over Current Protection RT9245C uses external resistor IMAX programmable over current trip point. comparator compares each inductor current with this reference current. RT9245C uses hiccup mode eliminate fault detection reduce output current when output shorted ground.
VIMAX RIMAX RCSN
SUM/M RCSN
RADJ
Figure Test Circuit
Comparator IIMAX
VADJ (mV)
VIMX
Setting RIMX
(mV)
Figure Over Current Comparator
Figure Linearity
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RT9245C
Over Current Protection
CH1:(5V/Div) CH2:(5V/Div)
some case with preferable current ratio instead current balance, corresponding technique provided. different physical environment each channel, necessary slightly adjust current loading between channels. Figure shows application circuit current ratio requirement. Applying along L+DCR branch R1+C//R2 branch
Time (25ms/Div)
Figure Over Current Protection soft start interval
Look corresponding conditions
Over Current Protection
CH1:(5V/Div) CH2:(5V/Div)
Thus
(R1//R2)
Then
Time (25ms/Div)
With internal current balance function, this phase would share 2)/R times current than other phases. Figure show different settings power stages. Figure shows performance current ratio compared with conventional current balance function Figure
0.3uH 0.6m
Figure Over Current Protection steady state Current Ratio Setting
+VCR1
Figure Setting current ratio function
0.3uH 0.6m
Figure Application circuit current ratio setting
Figure GM1~3 Setting current ratio function
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RT9245C
Current Ratio Function
Load Line without dead zone light loads
1.31 1.29
Dead Zone Compensation RCSN open
CORE
1.28 1.27 1.26 1.25 1.24 1.23
RCSN Dead Zone Compensation
Figure
Figure
Current Balance Function
VOUT
RCSN RCSN2
Figure Application circuit Referring Figure expressed
VOUT ILX_50% ILX_50% RCSN2 RCSN2 RCSN
Figure Dead Zone Elimination RT9245C samples holds inductor current period time-sharing sourcing current RCSN. light load condition when inductor current balance, voltage across sensing capacitor would negative. needs negative sense voltage. However, RT9245C CANNOT provide negative consequently cannot sense negative inductor current. This results dead zone load line performance shown Figure Therefore technique shown Figure required eliminate dead zone load line light load condition.
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where ILX_50% inductor current period. make sure RT9245C could sense inductor current, right hand side Equation should always positive: VOUT ILX_50% ILX_50% RCSN2 RCSN2 RCSN
Since RCSN2 RCSN practical application, Equation could simplified
VOUT ILX_50% RCSN2 RCSN
Figure shows that dead zone load line light load eliminated applying this technique.
DS9245C-02 March 2007
RT9245C
With external pull resistors tied pins, RT9245C converters different codes from into output voltage. Figure Figure show waveforms function. Output Voltage Offset Function meet Intel® requirement initial offset load line, RT9245C provides programmable initial offset function. External resistor RVOSS voltage source VOSS generate offset current IVOSS VOSS VOSS where VVOSS typical. quarter IVOSS flows through shown Figure Error amplifier would hold inverting equal VDAC VADJ. Thus output voltage subtracted from VDAC VADJ constant offset voltage. RFB1 VCORE VDAC VADJ VOSS positive output voltage offset possible connecting RVOSS instead GND. Please note that when RVOSS connected VDD, VVOSS typically half IVOSS flows through RFB1. VCORE rewritten VCORE VDAC VADJ RFB1 RVOSS
(Falling)
CORE
CH1:(5V/Div) CH2:(500mV/Div) CH3:(500mV/Div) CH4:(1V/Div)
VID125
VDAC 1.500, IOUT
Time (25s/Div)
Figure
Voltage Offset Function
1.284 1.282 1.28
(Rising)
CORE
CH3:(500mV/Div) CH4:(1V/Div) CH1:(5V/Div) CH2:(500mV/Div)
CORE
1.278 1.276 1.274 1.272 1.27 1.268
VID125
VDAC 1.500, IOUT
ROSS
Time (25s/Div)
Figure Load Line Setting Thermal Compensation VADJ AVG(IX) RADJ
Figure
IVOSS VDAC-VADJ
VOUT VDAC VADJ AVG(IX) current. properly resistor ADJ. Load line thermally compensated.
Figure Offset Setting
DS9245C-02 March 2007 www.richtek.com
RT9245C
PGOOD Function During start-up, RT9245C will detect 5VCC 12VIN (through pin). Figure 5VCC 12VIN ready during V(SS) Figure pulled FAULT. V(EAP) also equal GND. V(FB) VOUT will follow V(EAP) thus both V(FB) VOUT equal during During both 5VCC 12VIN ready, FAULT low, OPSS starts charging CSS. design RT9245C, (the maximal current sink source capability OPSS) limited time-variant. During 0.4V V(SS) ISS(T2) equal about 10uA. fault condition V(SS) PGOOD will pulled immediately also. RT9245C will turn side MOSFET turn high side MOSFET. VOUT will fall quickly protect from high voltage. typical waveform shown Figure
VOUT 5VCC VDAC OPSS COMP
ISS(T2)
4x10
FAULT
After V(SS) changes about 20uA. rising speed V(SS) becomes about times faster than Figure MOSFET will turn only V(SS) VTH_N1 (threshold voltage V(EAP) still
0.7V Before turns
Figure Soft Start Circuit
5VCC_ready DVD_ready
1.5x10 ISS(T3)
After V(SS) MOSFET turns V(EAP) starts rising. ISS(T4) still equal about 20uA. V(SS,EAP) equal VTH_N1. body effect MOSFET VTH_N1 increases with higher V(EAP). example, VOUT target 1.4V, V(SS,EAP) will equal about 0.7V beginning equal about 1.1V
PGOOD V(SS)
VOUT
9x10 ISS(T4)
VOUT very close target (within range ±40mV). internal timer starts. After about 1ms(T5), open-drain output PGOOD releases. After PGOOD releases, ISS(T6) becomes about 320uA accelerate OPSS. RT9245C enters normal operation mode capable follow fly. When fault conditions happens, V(SS) PGOOD will pulled immediately. fault condition 5VCC low, low, VID_OFF, RT9245C will turn both high side MOSFET side MOSFET. VOUT will fall slowly avoid negative VOUT. typical waveform shown Figure
Figure Soft Start Waveform
PGOOD V(SS)
VOUT
5VCC_Low DVD_Low VID_OFF
Figure Waveform 5VCC_Low, DVD_Low, VID_OFF
DS9245C-02 March 2007
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RT9245C
PGOOD V(SS)
Rising Slew Rate
VOUT
Figure Waveform Error Amplifier Characteristic fast response converter meet stringent output current transient response, RT9245C provides large slew rate capability high gain-bandwidth performance.
VCOMP
CH1:(500mV/Div) CH2:(2V/Div)
Time (250ns/Div)
Figure Falling Transient with 10pF Loading; Slew Rate 8V/us
4.7k
Falling Slew Rate
4.7k
VDAC
Figure Gain-Bandwidth Measurement signal divided signal
VCOMP
CH1:(500mV/Div) CH2:(2V/Div)
Time (250ns/Div)
Figure Rising Transient with 10pF Loading; Slew Rate 8V/us
DS9245C-02 March 2007
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RT9245C
180°
Figure Frequency Response with closed loop gain observe gain-bandwidth product; -3dB 10.86MHz Design Procedure Suggestion a.Output filter pole zero (Inductor, output capacitor value ESR). b.Error amplifier compensation sawtooth wave amplitude (compensation network). c.Kelvin sense VCORE. Current Loop Setting a.GM amplifier current (current sense component DCR, external resistor value). b.Over-current protection trip point (RIMAX resistor). Load Line Setting a.Droop amplitude (ADJ resistor). b.No load offset (RCSN2) c.DAC offset voltage setting (VOSS compen- sation network resistor RB1). Power Sequence external resistor capacitor. Layout a.Kelvin sense current sense amplifier input. b.Refer layout guide other items. Voltage Loop Setting Design Example Given Apply four phase converter VCORE 1.4V ILOAD 125A VDROOP 95mV with load Load Line) trip point each channel (S/H) inductor 25°C 0.3H COUT 5600F with equivalent ESR.
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DS9245C-02 March 2007
RT9245C
Compensation Setting Modulator Gain, Pole Zero From following formula Modulator Gain VIN/VRAMP 12/1.9 (i.e 16dB) where VRAMP Ramp amplitude saw-tooth wave Filter Pole 3.88kHz Zero 28kHz Compensation Network Select 1.5k, 15k, 2.7nF, 5.6pF, 680pF Type compensation scheme shown Figure calculation. 156kHz 3.9kHz Over-Current Protection Setting Consider temperature coef icient copper 3900ppm/°C,
VIMAX RIMAX 1.39m RIMAX
680pF 1.5k 5.6pF
2.7nF
Figure Type compensation network over loop gain with load shown Figure Figure
5.8kHz (C2//C1)
RIMAX 8.9k Soft-Start Capacitor Selection most application cases, 0.1µF good engineering value.
Middle Band Gain (i.e. 20dB)
Figure Frequency Response with Load
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RT9245C
Figure Frequency Response with Middle Load
Figure Frequency Response with Heavy Load
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DS9245C-02 March 2007
RT9245C
Layout Guide
Place high-power switching components first, separate them from sensitive nodes. Most critical path: current sense circuit most sensitive part converter. current sense resistors tied CSP1,2,3,4 should located more than inch from away from noise switching nodes. trace sense nodes should parallel short possible. Switching ripple current path: Input capacitor high side MOSFET. side MOSFET output capacitor. return path input output capacitor. Separate power signal GND. switching nodes (the connection node high/low side MOSFET inductor) most noisy points. Keep them away from sensitive small-signal node. Reduce parasitic minimum length, enough copper thickness avoiding via. MOSFET driver should closed MOSFET. compensation, bypass other function setting components should near away from noisy power path.
VOUT
COUT
Figure Power Stage Ripple Current Path
DS9245C-02 March 2007
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RT9245C
+12V 0.1uF BOOT UGATE PHASE LGATE PGND Locate near MOSFETs Thermal Couple CSPx CBOOT Next +12V VOSS COMP RCSN SGND RT9245C Locate next Next +5VIN
VCORE
COUT
RT9619
Figure Layout Consideration
Figure Layout power stage
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DS9245C-02 March 2007
RT9245C
Outline Dimension
Symbol
Dimensions Millimeters 0.850 0.050 0.800 0.178 9.601 0.650 6.300 4.293 0.450 6.500 4.496 0.762 1.200 0.152 1.050 0.305 9.804
Dimensions Inches 0.033 0.002 0.031 0.007 0.378 0.026 0.248 0.169 0.018 0.256 0.177 0.030 0.047 0.006 0.041 0.012 0.386
28-Lead TSSOP Plastic Package
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Richtek Technology Corporation
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