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For more information www.linear .com/L TM4603HV Typical applicaTion FeaTures DescripTion 6A, 28VIN DC/DC µModule with PLL, Output Tracking and Margining The LT M®4603HV is a complete 6A step-down switch mode DC/DC power supply with onboard switching controller, MOSFETs, inductor and all support components. The µModule TM is housed in a small surface mount 15mm × 15mm × 2.82mm LGA package. Operating over an input voltage range of 4.5 to 28V, the LTM4603HV supports an output voltage range of 0.6V to 5V as well as output voltage tracking and margining. The high efficiency design delivers 6A continuous current (8A peak). Only bulk input and output capacitors are needed to complete the design. The low profile (2.82mm) and light weight (1.7g) package easily mounts on the unused space on the back side of PC boards for high density point of load regulation. The µModule can be synchronized with an external clock for reducing undesirable frequency harmonics and allows PolyPhase ® operation for high load currents. A high switching frequency and adaptive on-time current mode architecture deliver a very fast transient response to line and load changes without sacrificing stability. An onboard remote sense amplifier can be used to accurately regulate an output voltage independent of load current. 2.5V/6A with 4.5V to 28V Input µModule Regulator
applicaTions
n Complete Switch Mode Power Supply n Wide Input Voltage Range: 4.5V to 28V n 6A DC Typical, 8A Peak Output Current n 0.6V to 5V Output Voltage n Output Voltage T racking and Margining n Remote Sensing for Precision Regulation n Typical Operating Frequency: 1MHz n PLL Frequency Synchronization n 1.5% Regulation n Current Foldback Protection (Disabled at Start-Up) n Pin Compatible with the LTM4601/LTM4601HV/ LTM4603 n Ultrafast T ransient Response n Current Mode Control n Up to 93% Efficiency at 5VIN, 3.3VOUT n Programmable Soft-Start n Output Overvoltage Protection n RoHS Compliant Package with Gold Finish Pads (e4) n Small Footprint, Low Profile (15mm × 15mm × 2.82mm) Sur face Mount LGA Package n Telecom and Networking Equipment n Servers n Industrial Equipment n Point of Load Regulation Efficiency vs Load Current with 24VIN VOUT VFB MARG0 MARG1 VOUT_LCL DIFFVOUT VOSNS+ VOSNS– PGOOD RUN COMP INTV CC DRVCC MPGM TRACK/SSPLLIN LTM4603HV ON/OFF 392k RSET 19.1k MARGIN CONTROL C OUT 4603HV TA01a VOUT 2.5V CLOCK SYNC TRACK/SS CONTROL 100pF CIN VIN fSETPGNDSGND 5% MARGIN VIN 4.5V TO 28V LOAD CURRENT (A) EFFICIENCY (%) 100 3 5 4603HV TA01b 1 2 4 6 7 24VIN, 1.8VOUT 24VIN, 2.5VOUT 24VIN, 3.3VOUT 24VIN, 5VOUT L, LT, LT C, LT M, Linear Technology, the Linear logo, µModule and PolyPhase are registered trademarks and L TpowerCAD is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611, 6677210.
For more information www.linear .com/L TM4603HV pin conFiguraTionabsoluTe MaxiMuM raTings INTVCC, DRVCC, VOUT_LCL, VOUT (VOUT ≤ 3.3V PLLIN, TRACK/SS, MPGM, MARG0, MARG1, 0.3V to 5V Operating Temperature Range (Note 2)....–40°C to 85°C 5°C 55°C to 125°C (Note 1) MARG1 DRVCC VFB PGOOD SGND V OSNS+ DIFFVOUT VOUT_LCL VOSNS– VIN PGND VOUT fSET MARG0 RUN COMP MPGM PLLIN INTVCC TRACK/SS LGA PACKAGE 118-LEAD (15mm × 15mm × 2.82mm) TOP VIEW TJMAX = 125°C, θJA = 15°C/W, θJC = 6°C/W θJA DERIVED FROM 95mm × 76mm PCB WITH 4 LAYERS, WEIGHT = 1.7g elecTrical characTerisTics The l denotes the specifications which apply over the full operating temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration, RSET = 40.2k. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VIN(DC) Input DC Voltage l 4.5 28 V VOUT(DC) Output Voltage CIN = 10µF ×2, COUT = 2× 100µF X5R Ceramic VIN = 5V, VOUT = 1.5V, IOUT = 0A VIN = 12V, VOUT = 1.5V, IOUT = 0A l l 1.478 1.478 1.5 1.5 1.522 1.522 V V Input Specifications V IN(UVLO) Undervoltage Lockout Threshold I OUT = 0A 3.2 4 V IINRUSH(VIN) Input Inrush Current at Startup I OUT = 0A. VOUT = 1.5V VIN = 5V VIN = 12V 0.6 0.7 A A orDer inForMaTion PART NUMBER PAD OR BALL FINISH PART MARKING* PACKAGE TYPE MSL RA TING TEMPERATURE RANGE (SEE NOTE 2)DEVICE FINISH CODE LTM4603HVEV#PBF Au (RoHS) LTM4603HVV e4 LGA 3 –40°C to 85°C LTM4603HVIV#PBF
- Consult Marketing for parts specified with wider operating temperature ranges. *Pad or ball finish code is per IPC/JEDEC J-STD-609.
- Terminal Finish Part Marking: www.linear.com/leadfree
- Recommended LGA and BGA PCB Assembly and Manufacturing Procedures: www.linear.com/umodule/pcbassembly
- LGA and BGA Package and T ray Drawings: www.linear.com/packaging
For more information www.linear .com/L TM4603HV elecTrical characTerisTics The l denotes the specifications which apply over the full operating temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration, RSET = 40.2k. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS IQ(VIN,NOLOAD) Input Supply Bias Current VIN = 12V, No Switching VIN = 12V, VOUT = 1.5V, Switching Continuous VIN = 5V, No Switching VIN = 5V, VOUT = 1.5V, Switching Continuous Shutdown, RUN = 0, VIN = 12V 3.8 2.5 mA mA mA mA µA I S(VIN) Input Supply Current VIN = 12V, VOUT = 1.5V, IOUT = 6A VIN = 12V, VOUT = 3.3V, IOUT = 6A VIN = 5V, VOUT = 1.5V, IOUT = 6A 0.92 1.83 2.12 A A A INTV CC VIN = 12V, RUN > 2V No Load 4.7 5 5.3 V Output Specifications IOUTDC Output Continuous Current Range V IN = 12V, VOUT = 1.5V (Note 5) 0 6 A ΔVOUT(LINE) VOUT Line Regulation Accuracy VOUT = 1.5V, IOUT = 0A, VIN = 4.5V to 28V l 0.3 % ΔVOUT(LOAD) VOUT Load Regulation Accuracy V OUT = 1.5V, IOUT = 0A to 6A, VIN = 12V with Remote Sense Amp (Note 5) l 0.25 % VOUT(AC) Output Ripple Voltage IOUT = 0A, COUT = 2× 100µF X5R Ceramic VIN = 12V, VOUT = 1.5V VIN = 5V, VOUT = 1.5V mVP-P mVP-P fS Output Ripple Voltage Frequency I OUT = 3A, VIN = 12V, VOUT = 1.5V 1000 kHz ΔVOUT(START) Turn-On Overshoot COUT = 200µF VOUT = 1.5V, IOUT = 0A, TRACK/SS = 10nF VIN = 12V VIN = 5V mV mV t START Turn-On Time COUT = 200µF, TRACK/SS = Open VOUT = 1.5V, IOUT = 1A Resistive Load VIN = 12V VIN = 5V 0.5 0.5 ms ms ΔV OUTLS Peak Deviation for Dynamic Load Load: 0% to 50% to 0% of Full Load, COUT = 2× 22µF Ceramic, 470µF 4V Sanyo POSCAP VIN = 12V VIN = 5V mV mV t SETTLE Settling Time for Dynamic Load Step Load: 0% to 50% to 10% of Full Load VIN = 12V µs IOUTPK Output Current Limit COUT = 2× 100µF X5R Ceramic VIN = 12V, VOUT = 1.5V VIN = 5V, VOUT = 1.5V A A Remote Sense Amp (Note 3) V OSNS+, VOSNS– CM Range Common Mode Input V oltage Range V IN = 12V, RUN > 2V 0 INTVCC – 1 V DIFFVOUT Range Output Voltage Range VIN = 12V, DIFFVOUT Load = 100k 0 INTVCC – 1 V VOS Input Offset Voltage Magnitude 1.25 mV AV Differential Gain 1 V/V GBP Gain Bandwidth Product 3 MHz SR Slew Rate 2 V/µs RIN Input Resistance VOSNS+ to GND 20 kW CMRR Common Mode Rejection Ratio 100 dB
For more information www.linear .com/L TM4603HV elecTrical characTerisTics The l denotes the specifications which apply over the full operating temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration, RSET = 40.2k. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Control Stage VFB Error Amplifier Input Voltage Accuracy IOUT = 0A, VOUT = 1.5V l 0.594 0.6 0.606 V VRUN RUN Pin On/Off Threshold 1 1.5 1.9 V ITRACK/SS Soft-Start Charging Current V TRACK/SS = 0V –1 –1.5 –2 µA tON(MIN) Minimum On Time (Note 4) 50 100 ns tOFF(MIN) Minimum Off Time (Note 4) 250 400 ns RPLLIN PLLIN Input Resistance 50 kW IDRVCC Current into DRVCC Pin VOUT = 1.5V, IOUT = 1A, DRVCC = 5V 18 25 mA RFBHI Resistor Between VOUT_LCL and VFB 60.098 60.4 60.702 k W VMPGM Margin Reference Voltage 1.18 V VMARG0, VMARG1 MARG0, MARG1 Voltage Thresholds 1.4 V PGOOD Output ΔVFBH PGOOD Upper Threshold VFB Rising 7 10 13 % ΔVFBL PGOOD Lower Threshold VFB Falling –7 –10 –13 % ΔVFB(HYS) PGOOD Hysteresis VFB Returning (Note 4) 1.5 3 % VPGL PGOOD Low Voltage IPGOOD = 5mA 0.15 0.4 V Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTM4603HV is tested under pulsed load conditions such that T J ≈ TA. The LTM4603HVEV is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. The LTM4603HVIV is guaranteed over the –40°C to 85°C operating temperature range. Note 3: Remote sense amplifier recommended for ≤3.3V output. Note 4: 100% tested at die level only. Note 5: See output current derating curves for different V IN, VOUT and TA.
For more information www.linear .com/L TM4603HV Typical perForMance characTerisTics (See Figure 20 for all curves) Efficiency vs Load Current with 5VIN Efficiency vs Load Current with 12VIN Efficiency vs Load Current with 24VIN 1.2 V T ransient Response 1.5 V T ransient Response 2.5V T ransient Response 3.3V T ransient Response 1.8 V T ransient Response LOAD CURRENT (A) EFFICIENCY (%) 100 2 4 5 4603HV G01 1 3 6 7 5VIN, 0.6VOUT 5VIN, 1.2VOUT 5VIN, 1.5VOUT 5VIN, 1.8VOUT 5VIN, 2.5VOUT 5VIN, 3.3VOUT LOAD CURRENT (A) EFFICIENCY (%)60 100 2 4 5 4603HV G02 1 3 6 7 12VIN, 1.2VOUT 12VIN, 1.5VOUT 12VIN, 1.8VOUT 12VIN, 2.5VOUT 12VIN, 3.3VOUT 12VIN, 5VOUT LOAD CURRENT (A) EFFICIENCY (%) 100 3 5 4603HV G03 1 2 4 6 7 24VIN, 1.8VOUT 24VIN, 2.5VOUT 24VIN, 3.3VOUT 24VIN, 5VOUT LOAD STEP 1A/DIV VOUT 50mV/DIV 25µs/DIV 4603HV G04 1.2V AT 3A/µs LOAD STEP COUT: 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP LOAD STEP 1A/DIV VOUT 50mV/DIV 25µs/DIV 4603HV G06 1.8V AT 3A/µs LOAD STEP C OUT: 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP LOAD STEP 1A/DIV VOUT 50mV/DIV 25µs/DIV 4603HV G07 2.5V AT 3A/µs LOAD STEP C OUT: 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP LOAD STEP 1A/DIV VOUT 50mV/DIV 25µs/DIV 4603HV G08 3.3V AT 3A/µs LOAD STEP C OUT: 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP LOAD STEP 1A/DIV VOUT 50mV/DIV 25µs/DIV 4603HV G05 1.5V AT 3A/µs LOAD STEP C OUT: 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP
For more information www.linear .com/L TM4603HV Typical perForMance characTerisTics (See Figure 20 for all curves) Start-Up, IOUT = 6A (Resistive Load)Start-Up, IOUT = 0A VIN to VOUT Step-Down Ratio Short-Circuit Protection, IOUT = 0A Short-Circuit Protection, I OUT = 6A VOUT 0.5V/DIV IIN 0.5A/DIV 1ms/DIV 4603HV G09 VIN = 12V VOUT = 1.5V COUT = 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP SOFT-START = 3.9nF VOUT 0.5V/DIV IIN 0.5A/DIV 1ms/DIV 4603HV G10 VIN = 12V VOUT = 1.5V COUT = 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP SOFT-START = 3.9nF VOUT 0.5V/DIV IIN 2A/DIV 100µs/DIV 4603HV G11 VIN = 12V VOUT = 1.5V COUT = 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP SOFT-START = 3.9nF VOUT 0.5V/DIV IIN 2A/DIV 100µs/DIV
4603 G12
VIN = 12V VOUT = 1.5V COUT = 1x 22µF, 6.3V CERAMIC 1x 330µF, 4V SANYO POSCAP SOFT-START = 3.9nF INPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 3.0 4.0 5.5 5.0 4603HV G13 2.0 1.0 2.5 3.5 4.5 1.5 0.5 4 8 12 2820 24 3.3V OUTPUT WITH 82.5k FROM VOUT TO fSET 5V OUTPUT WITH 150k RESISTOR ADDED FROM fSET TO GND 5V OUTPUT WITH NO RESISTOR ADDED FROM fSET TO GND 2.5V OUTPUT 1.8V OUTPUT 1.5V OUTPUT 1.2V OUTPUT
For more information www.linear .com/L TM4603HV pin FuncTions VIN (Bank 1): Power Input Pins. Apply input voltage be- tween these pins and PGND pins. Recommend placing input decoupling capacitance directly between V IN pins and PGND pins. VOUT (Bank 3): Power Output Pins. Apply output load between these pins and PGND pins. Recommend placing output decoupling capacitance directly between these pins and PGND pins. See Figure 17. PGND (Bank 2): Power ground pins for both input and output returns. V OSNS– (Pin M12): (–) Input to the Remote Sense Ampli- fier. This pin connects to the ground remote sense point. The remote sense amplifier is used for V OUT ≤3.3V. Tie to INTVCC if not used. VOSNS+ (Pin J12): (+) Input to the Remote Sense Ampli- fier. This pin connects to the output remote sense point. The remote sense amplifier is used for V OUT ≤3.3V. Tie to ground if not used. DIFFV OUT (Pin K12): Output of the Remote Sense Amplifier. This pin connects to the V OUT_LCL pin. Leave floating if remote sense amplifier is not used. DRV CC (Pin E12): This pin normally connects to INTV CC for powering the internal MOSFET drivers. This pin can be biased up to 6V from an external supply with about 50mA capability, or an external circuit shown in Figure 18. This improves efficiency at the higher input voltages by reducing power dissipation in the module. (See Package Description for Pin Assignment) INTVCC (Pin A7): This pin is for additional decoupling of the 5V internal regulator. PLLIN (Pin A8): External Clock Synchronization Input to the Phase Detector. This pin is internally terminated to SGND with a 50k resistor. Apply a clock with a high level above 2V and below INTV CC. See the Applications Information section. TRACK/SS (Pin A9): Output Voltage T racking and Soft- Start Pin. When the module is configured as a master output, then a soft-start capacitor is placed on this pin to ground to control the master ramp rate. A soft-start capacitor can be used for soft-start turn on as a stand alone regulator. Slave operation is performed by putting a resistor divider from the master output to ground, and connecting the center point of the divider to this pin. See the Applications Information section. MPGM (Pin A12): Programmable Margining Input. A re- sistor from this pin to ground sets a current that is equal to 1.18V/R. This current multiplied by 10 kΩ will equal a value in millivolts that is a percentage of the 0.6V refer- ence voltage. See the Applications Information section. To parallel LTM4603HVs, each requires an individual MPGM resistor. Do not tie MPGM pins together. f SET (Pin B12): Frequency Set Internally to 1MHz. An external resistor can be placed from this pin to ground to increase frequency. See the Applications Information section for frequency adjustment. MARG1 DRVCC VFB PGOOD SGND V OSNS+ DIFFVOUT VOUT_LCL VOSNS– VIN PGND VOUT fSET MARG0 RUN COMP MPGM PLLIN INTVCC TRACK/SS LGA PACKAGE 118-LEAD (15mm × 15mm × 2.82mm) TOP VIEW
For more information www.linear .com/L TM4603HV pin FuncTions (See Package Description for Pin Assignment) VFB (Pin F12): The Negative Input of the Error Amplifier. Internally, this pin is connected to VOUT_LCL with a 60.4k precision resistor. Different output voltages can be pro- grammed with an additional resistor between V FB and SGND pins. See the Applications Information section. MARG0 (Pin C12): This pin is the LSB logic input for the margining function. Together with the MARG1 pin will determine if margin high, margin low or no margin state is applied. The pin has an internal pull-down resistor of 50k. See the Applications Information section. MARG1 (Pin D12): This pin is the MSB logic input for the margining function. Together with the MARG0 pin will determine if margin high, margin low or no margin state is applied. The pin has an internal pull-down resistor of 50k. See the Applications Information section. SGND (Pin H12): Signal Ground. This pin connects to PGND at output capacitor point. COMP (Pin A11): Current Control Threshold and Error Amplifier Compensation Point. The current comparator threshold increases with this control voltage. The voltage ranges from 0V to 2.4V with 0.7V corresponding to zero sense voltage (zero current). PGOOD (Pin G12): Output Voltage Power Good Indicator. Open-drain logic output that is pulled to ground when the output voltage is not within ±10% of the regulation point, after a 25µs power bad mask timer expires. RUN (Pin A10): Run Control Pin. A voltage above 1.9V will turn on the module, and when below 1V, will turn off the module. A programmable UVLO function can be accomplished by connecting to a resistor divider from VIN to ground. See Figure 1. This pin has a 5.1V Zener to ground. Maximum pin voltage is 5V. Limit current into the RUN pin to less than 1mA. VOUT_LCL (Pin L12): VOUT connects directly to this pin to bypass the remote sense amplifier, or DIFFVOUT connects to this pin when remote sense amplifier is used.
Figure 1. Simplified LTM4603HV Block Diagram Decoupling requireMenTs TA = 25°C. Use Figure 1 configuration.
For more information www.linear .com/L TM4603HV operaTion Power Module Description The LTM4603HV is a standalone nonisolated switching mode DC/DC power supply. It can deliver up to 6A of DC output current with few external input and output capaci- tors. This module provides precisely regulated output volt- age programmable via one external resistor from 0.6VDC to 5.0VDC over a 4.5V to 28V wide input voltage. The typical application schematic is shown in Figure 20. The LTM4603HV has an integrated constant on-time current mode regulator, ultralow R DS(ON) FETs with fast switching speed and integrated Schottky diodes. The typi- cal switching frequency is 1MHz at full load. With current mode control and internal feedback loop compensation, the LTM4603HV module has sufficient stability margins and good transient performance under a wide range of operating conditions and with a wide range of output capacitors, even all ceramic output capacitors. Current mode control provides cycle-by-cycle fast current limit. Besides, foldback current limiting is provided in an overcurrent condition while V FB drops. Internal overvolt- age and undervoltage comparators pull the open-drain PGOOD output low if the output feedback voltage exits a ±10% window around the regulation point. Furthermore, in an overvoltage condition, internal top FET Q1 is turned off and bottom FET Q2 is turned on and held on until the overvoltage condition clears. Pulling the RUN pin below 1V forces the controller into its shutdown state, turning off both Q1 and Q2. At low load current, the module works in continuous current mode by default to achieve minimum output voltage ripple. When DRV CC pin is connected to INTV CC an integrated 5V linear regulator powers the internal gate drivers. If a 5V external bias supply is applied on the DRVCC pin, then an efficiency improvement will occur due to the reduced power loss in the internal linear regulator. This is especially true at the higher input voltage range. The LTM4603HV has a very accurate differential remote sense amplifier with very low offset. This provides for very accurate output voltage sensing at the load. The MPGM pin, MARG0 pin and MARG1 pin are used to sup- port voltage margining, where the percentage of margin is programmed by the MPGM pin, and the MARG0 and MARG1 select margining. The PLLIN pin provides frequency synchronization of the device to an external clock. The TRACK/SS pin is used for power supply tracking and soft-start programming.
Figure 20. External requirements for a particular application. down ratio that can be achieved for a given input voltage. The PWM controller has an internal 0.6V reference voltage. Table 1. RSET Standard 1% Resistor Values vs VOUT PGM resistor on the MPGM pin programs the current.
- 10k where RPGM is the resistor value to place on the MPGM pin to ground. The margining voltage, V OUT(MARGIN), will be added or subtracted from the nominal output voltage as determined by the state of the MARG0 and MARG1 pins. See the truth table below: MARG1 MARG0 MODE LOW LOW NO MARGIN LOW HIGH MARGIN UP HIGH LOW MARGIN DOWN HIGH HIGH NO MARGIN Input Capacitors LTM4603HV module should be connected to a low AC impedance DC source. Input capacitors are required to be placed adjacent to the module. In Figure 20, the 10µF ceramic input capacitors are selected for their ability to handle the large RMS current into the converter. An input bulk capacitor of 100µF is optional. This 100µF capacitor is only needed if the input source impedance is compromised by long inductive leads or traces. For a buck converter, the switching duty-cycle can be estimated as: D = VOUT VIN Without considering the inductor ripple current, the RMS current of the input capacitor can be estimated as: ICIN(RMS) = IOUT(MAX) η% • D •(1−D) In the above equation, η% is the estimated efficiency of the power module. CIN can be a switcher-rated electrolytic aluminum capacitor, OS-CON capacitor or high value ce- ramic capacitor. Note the capacitor ripple current ratings
the ramp of the internal reference and the output voltage. driven with a logic input not to exceed 5V. See the Simplified Block Diagram (Figure 1). ages. Table 2 is provided for most application requirements. L TpowerCAD is available for control loop optimization. Figure 5. Coincident T racking Schematic Figure 6. Coincident Output T racking Characteristics
n is the number of paralleled modules. maintained at 100°C or below for the derating curves.
Figure 10. BGA Heat Sink Figure 11. No Heat Sink Figure 12. BGA Heat Sink Figure 13. No Heat Sink Figure 14. BGA Heat Sink Figure 15. No Heat Sink Figure 16. BGA Heat Sink
1635 G24
Table 2. Output Voltage Response Versus Component Matrix (Refer to Figure 20)
Table 4. 3.3V Output Table 3. 1.5V Output
For more information www.linear .com/L TM4603HV applicaTions inForMaTion Example for 5V Output LTM4603HV minimum on-time = 100ns tON = ((VOUT • 10pf)/IfSET), for VOUT > 4.8V use 4.8V LTM4603HV minimum off-time = 400ns tOFF = t– tON, where t = 1/Frequency Duty Cycle = tON/t or VOUT/VIN Equations for setting frequency: IfSET = (VIN/(3 • RfSET)), for 28V input operation, IfSET = 281µA, tON = ((4.8V • 10 pF)/IfSET), tON = 171ns, where the internal RfSET is 33.2k. Frequency = (VOUT/(VIN • tON)) = (5V/(28V • 171 ns)) ~ 1MHz. The inductor ripple cur- rent begins to get high at the higher input voltages due to a larger voltage across the inductor. This is shown in the Inductor Ripple Current vs Duty Cycle graph as over 4A at 18% duty cycle. The inductor ripple current can be lowered at the higher input voltages by adding an external resistor from fSET to ground to increase the switching frequency. A 3A ripple current is chosen, and the total peak current is equal to 1/2 of the 3A ripple current plus the output current. The 5V output current is limited to 5A, so total peak current is less than 6.5A. This is below the 8A peak specified value. A 150k resistor is placed from fSET to ground, and the parallel combination of 150k and 33.2k equates to 27.2k. The IfSET calculation with 27.2k and 28V input voltage equals 343µA. This equates to a tON of 140ns. This will increase the switching frequency from 1MHz to ~1.28MHz for the 28V to 5V conversion. The minimum on time is above 100ns at 28V input. Since the switching frequency is approximately constant over input and output conditions, then the lower input voltage range is limited to 10V for the 1.28MHz operation due to the 400ns minimum off-time. Equation: tON = (VOUT/VIN) • (1/ Frequency) equates to a 382ns on time, and a 400ns off- time. The VIN to VOUT Step-Down Ratio curve reflects an operating range of 10V to 28V for 1.28MHz operation with a 150k resistor to ground (shown in Figure 18), and an 8V to 16V operating range for fSET floating. These modifications are made to provide wider input voltage ranges for the 5V output designs while limiting the inductor ripple current, and maintaining the 400ns minimum off-time. Example for 3.3V Output LTM4603HV minimum on-time = 100ns tON = ((3.3V • 10pF)/IfSET) LTM4603HV minimum off-time = 400ns tOFF = t – tON, where t = 1/Frequency Duty Cycle (DC) = tON/t or VOUT/VIN Equations for setting frequency: IfSET = (VIN/(3 • RfSET)), for 28V input operation, I fSET = 281µA, tON = ((3.3V • 1 0 pf)/IfSET), tON = 117ns, where the internal RfSET is 33.2k. Frequency = (V OUT/(VIN • tON)) = (3.3V/(28V • 117ns )) ~ 1MHz. The minimum on-time and minimum off-time are within specification at 117ns and 883ns. But the 4.5V minimum input for converting 3.3V output will not meet the minimum off-time specification of 400ns. tON = 733ns, Frequency = 1MHz, tOFF = 267ns. Solution Lower the switching frequency at lower input voltages to allow for higher duty cycles, and meet the 400ns minimum off-time at 4.5V input voltage. The off-time should be about 500ns with 100ns guard band included. The duty cycle for (3.3V/4.5V) = ~73%. Frequency = (1 – DC)/t OFF or (1 – 0.73)/500ns = 540kHz. The switching frequency needs to be lowered to 540kHz at 4.5V input. t ON = DC/ frequency, or 1.35µs. The f SET pin voltage compliance is 1/3 of VIN, and the IfSET current equates to 45µA with the internal 33.2k. The IfSET current needs to be 24µA for 540kHz operation. A resistor can be placed from VOUT to fSET to lower the effective IfSET current out of the fSET pin to 24µA. The f SET pin is 4.5V/3 =1.5V and V OUT = 3.3V, therefore an 82.5k resistor will source 21µA into the fSET node and lower the IfSET current to 24µA. This enables the 540kHz operation and the 4.5V to 28V input operation for down converting to 3.3V output as shown in Figure 19. The frequency will scale from 540kHz to 1.27MHz over this input range. This provides for an effective output current of 5A over the input range.
Figure 21. 2-Phase, Parallel 2.5V at 12A Design Figure 20. Typical 4.5V-28VIN, 1.5V at 6A Design
4603 F18
0 PHASE
180 PHASE
Figure 22. 2-Phase, 3.3V and 2.5V at 6A with T racking Figure 23. 2-Phase, 1.8V and 1.5V at 6A with T racking
For more information www.linear .com/L TM4603HV package DescripTion 118-Lead (15mm × 15mm × 2.82mm) (Reference L TC DWG # 05-08-1801 Rev B) Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. 5. PRIMARY DATUM -Z- IS SEATING PLANE 6. THE TOTAL NUMBER OF PADS: 118
7 PACKAGE ROW AND COLUMN LABELING MAY VARY
AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULL Y NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 2. ALL DIMENSIONS ARE IN MILLIMETERS LAND DESIGNATION PER JESD MO-222, SPP-010 DETAILS OF PAD #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE PAD #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE PACKAGE TOP VIEW PIN “A1” CORNER X Y aaa Z aaa Z PACKAGE BOTTOM VIEW C(0.30) PAD 1 SEE NOTES SUGGESTED PCB LAYOUT TOP VIEW LGA 118 1212 REV B L TMXXXXXX µModule TRAY PIN 1 BEVEL PACKAGE IN TRAY LOADING ORIENTATION COMPONENT PIN “A1” DETAIL A 0.0000 0.0000 D 0.630 ±0.025 Ø 118x E b e e b F G 0.6350 0.6350 1.9050 1.9050 3.1750 3.1750 4.4450 4.4450 5.7150 5.7150 6.9850 6.9850 6.9850 5.7150 5.7150 4.4450 4.4450 3.1750 3.1750 1.9050 1.9050 0.6350 0.6350 6.9850 F G HM L J K E A B C D DETAIL A 0.630 ±0.025 SQ. 118x DETAIL B PACKAGE SIDE VIEW bbb Z S Y X eee SYMBOL A b D E e F G aaa bbb eee MIN 2.72 0.60 0.27 2.45 NOM 2.82 0.63 15.00 15.00 1.27 13.97 13.97 0.32 2.50 MAX 2.92 0.66 0.37 2.55 0.15 0.10 0.05 NOTES DIMENSIONS TOTAL NUMBER OF LGA PADS: 118 DETAIL B SUBSTRATEMOLD CAP Z A SEE NOTES
For more information www.linear .com/L TM4603HV Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
revision hisTory
REV DATE DESCRIPTION PAGE NUMBER A 6/14 Updated Absolute Maximum Ratings. Updated the Order Information table. Updated the Electrical Characteristics table. Updated the Pin Functions information. Updated the Output Voltage Programming and Margining section. Updated the PLLIN section. Updated the Applications Information section. Updated Figure 18. 2-4 7-8
For more information www.linear .com/L TM4603HV LINEAR TECHNOLOGY CORPORATION 2007 LT 0614 REV A • PRINTED IN USA Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507 l www.linear .com/L TM4603HV relaTeD parTs PART NUMBER DESCRIPTION COMMENTS LTC2900 Quad Supply Monitor with Adjustable Reset Timer Monitors Four Supplies; Adjustable Reset Timer LTC2923 Power Supply T racking Controller T racks Both Up and Down; Power Supply Sequencing LT3825/LT3837 Synchronous Isolated Flyback Controllers No Opto-Coupler Required; 3.3V, 12A Output; Simple Design LTM4600 10A DC/DC µModule Fast T ransient Response LTM4601 12A DC/DC µModule with PLL, Output T racking and Margining, LTM4603HV Pin Compatible LTM4602 6A DC/DC µModule Pin Compatible with the LTM4600 LTM4603 6A DC/DC µModule with T racking PLL/Margining Pin Compatible with the LTM4601