LTM4632 Ultrathin, Triple Output, Step-Down µModule Regulator for DDR-QDR4 Memory Description Features Complete DDR-QDR4 SRAM Power Solution Including VDDQ, VTT, VTTR (or VREF) nn Solution in 0.5cm2 (Dual-Sided PCB) nn Wide Input Voltage Range: 3.6V to 15V nn 3.3V Input Compatible with V Tied to INTV IN CC nn 0.6V to 2.5V Output Voltage Range nn Dual ±3A DC Output Current with Sink and Source Capability nn ±1.5%, ±10mA Buffered VTTR = VDDQ/2 Output nn 3A VDDQ + 3A VTT or Dual Phase Single 6A VTT nn ±1.5% Maximum Total Output Voltage Regulation Error Over Load, Line and Temperature nn Current Mode Control, Fast Transient Response nn External Frequency Synchronization nn Multiphase Parallelable with Current Sharing nn Selectable Burst Mode® Operation nn Overvoltage Input and Overtemperature Protection nn Power Good Indicator nn Ultrathin 6.25mm × 6.25mm × 1.82mm LGA and 6.25mm × 6.25mm × 2.42mm BGA Packages The LTM®4632 is an ultrathin triple output step-down µModule® (power module) regulator to provide complete power solution for DDR-QDR4 SRAM. Operating from a 3.6V to 15V input voltage, the LTM4632 supports two ±3A output rails, both sink and source capable, for VDDQ and VTT, plus a 10mA low noise reference VTTR output. Both VTT and VTTR track and are equal to VDDQ/2. Housed in a 6.25mm × 6.25mm × 1.82mm LGA and 6.25mm × 6.25mm × 2.42mm BGA packages, the LTM4632 includes the switching controller, power FETs, inductors and support components. Alternatively, the power module can also be configured as a two phase single ±6A output VTT. Only a few ceramic input and output capacitors are needed to complete the design. nn The LTM4632 supports selectable Burst Mode operation (CH1 only) and output voltage tracking for supply rail sequencing. Its high switching frequency and current mode control enable a very fast transient response to line and load changes without sacrificing stability. Fault protection features include overvoltage input, overcurrent and overtemperature protection. Applications The LTM4632 is RoHS compliant with Pb-free finish. DDR Memory Power Supply nn General Purpose Point of Load Conversion nn Telecom, Networking and Industrial Equipment nn L, LT, LTC, LTM, µModule, Burst Mode, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical Application Output Efficiency vs Load Current QDR4 Memory Power µModule Regulator 10µF 25V VDDQ VIN RUN1 RUN2 LTM4632 INTVCC SYNC/MODE VOUT1 VOUT2 22µF 4V VTTR FB1 TRACK/SS1 COMP1 VDDQIN COMP2 VTT 0.65V, ±3A VTTR 0.65V, 10mA GND 90 VDDQ 1.3V, 3A 52.3k 4632 TA01a EFFICIENCY (%) 22µF 4V PGOOD1 PGOOD2 VIN 3.6V TO 15V 95 85 80 75 70 65 5V INPUT 12V INPUT 0 1 2 LOAD CURRENT (A) 3 4632 TA01b 4632fa For more information www.linear.com/LTM4632 1 LTM4632 Absolute Maximum Ratings Pin Configuration (See Pin Functions, Pin Configuration Table) (Note 1) VIN.............................................................. –0.3V to 16V VOUT.............................................................. –0.3V to 6V PGOOD1, PGOOD2...................................... –0.3V to 16V RUN1, RUN2....................................... –0.3V to VIN+0.3V INTVCC, TRACK/SS1, VDDQIN, VTTR.......... –0.3V to 3.6V MODE/SYNC, COMP1, COMP2, FB1, FB2................................................. –0.3V to INTVCC Operating Internal Temperature Range (Notes 2, 3, 5)............................................. –40 to 125°C Storage Temperature Range....................... –55 to 125°C Peak Solder Reflow Body Temperature.................. 260°C Order Information TOP VIEW SYNC/ COMP2 GND MODE GND COMP1 5 PGOOD2 VDDQIN INTVCC 4 VTTR VIN 3 RUN2 2 VIN VOUT2 1 GND PGOOD1 FB1 VIN TRACK/SS1 RUN1 VIN GND VOUT1 A B C D E LGA PACKAGE 25-LEAD (6.25mm × 6.25mm × 1.82mm) BGA PACKAGE 25-LEAD (6.25mm × 6.25mm × 2.42mm) TJMAX = 125°C, θJCtop = 17°C/W, θJCbottom = 11°C/W, θJB +θBA = 22°C/W, θJA = 20°C/W WEIGHT = 0.21g http://www.linear.com/product/LTM4632#orderinfo PART MARKING* PAD OR BALL FINISH DEVICE FINISH CODE PACKAGE TYPE MSL RATING LTM4632EV#PBF Au (RoHS) LTM4632V e4 LGA 3 –40°C to 125°C LTM4632IV#PBF Au (RoHS) LTM4632V e4 LGA 3 –40°C to 125°C PART NUMBER TEMPERATURE RANGE (SEE NOTE 2) LTM4632EY#PBF SAC305 (RoHS) LTM4632Y e1 BGA 3 –40°C to 125°C LTM4632IY#PBF SAC305 (RoHS) LTM4632Y e1 BGA 3 –40°C to 125°C SnPb (63/37) LTM4632Y e0 BGA 3 –40°C to 125°C LTM4632IY • Consult Marketing for parts specified with wider operating temperature ranges. *Device temperature grade is indicated by a label on the shipping container. 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 Tray Drawings: www.linear.com/packaging 4632fa 2 For more information www.linear.com/LTM4632 LTM4632 Electrical Characteristics The l denotes the specifications that apply over the specified internal operating temperature range (Note 2). Specified as each individual output channel at TA = 25°C (Note 2), VIN = 12V, unless otherwise noted, per the typical application in Figure 19 SYMBOL PARAMETER CONDITIONS MIN VIN Input DC Voltage l 3.6 VIN_3.3 3.3V Input DC Voltage VIN = INTVCC l 3.1 VOUT1(RANGE) VOUT2(RANGE) Output Voltage Range VIN = 3.6V to 15V l l 0.6 l 1.28 TYP MAX UNITS 15 V 3.3 3.5 V 2.5 1.8 V V 1.32 V 3 A Output Specification (Channel 1) VOUT1(DC) IOUT1(DC) IQ1(VIN) CH1 Output Voltage, Total Variation CIN = 22µF, COUT = 100µF Ceramic with Line and Load RFB1 = 51.7k, MODE = GND, IOUT = –3A to 3A CH1 Output Continuous Current VIN = 12V, VOUT1 = 1.3V (Note 3) Range CH1 Input Supply Bias Current 1.30 –3 VIN = 12V, VOUT1 = 1.3V, MODE = GND VIN = 12V, VOUT1 = 1.3V, MODE = INTVCC Shutdown, RUN1 = GND 13 400 40 mA µA µA IS1(VIN) CH1 Input Supply Current VIN = 12V, VOUT1 = 1.3V, IOUT = 3A ΔVOUT1(Line)/VOUT1 CH1 Line Regulation Accuracy VOUT1 = 1.3V, VIN = 3.6V to 15V, IOUT1 = 0A l 0.01 0.4 0.05 A ΔVOUT1(Load)/VOUT1 CH1 Load Regulation Accuracy VOUT1 = 1.3V, IOUT = –3A to 3A l 0.2 1.0 VOUT1(AC) CH1 Output Ripple Voltage IOUT = 0A, COUT = 47µF Ceramic VIN = 12V, VOUT1 = 1.3V 30 mV ΔVOUT1(START) CH1 Turn-On Overshoot IOUT = 0A, COUT = 47µF Ceramic, TRACK/SS1 = –0.1µF, VIN = 12V, VOUT1 = 1.3V 30 mV tSTART Turn-On Time COUT = 100µF Ceramic, TRACK/SS1 = 0.01µF No Load, VIN = 12V, VOUT1 = 1.3V 1.2 ms ΔVOUTLS1 CH1 Peak Deviation for Dynamic Load Load: 0% to 25% to 0% of Full Load COUT = 47µF Ceramic, VIN = 12V, VOUT1 = 1.3V 85 mV tSETTLE1 CH1 Settling Time for Dynamic Load Step Load: 0% to 25% to 0% of Full Load COUT = 47µF Ceramic, VIN = 12V, VOUT1 = 1.3V 20 µs IOUTPK1 CH1 Output Current Limit VIN = 12V, VOUT1 = 1.3V 4.5 A %/V % Output Specification (Channel 2) VOUT2(DC) CH2 Output Voltage, Total Variation CIN = 22µF, COUT = 100µF Ceramic with Line and Load VDDQIN= 1.3V, MODE = GND, IOUT = –3A to 3A IOUT2(DC) CH2 Output Continuous Current Range VIN = 12V, VDDQIN = 1.3V (Note 3) IQ2(VIN) CH2 Input Supply Bias Current VIN = 12V, VDDQIN = 1.3V, MODE = GND Shutdown, RUN2 = 0 l 637 650 –3 663 3 7 40 mV A mA µA IS2(VIN) CH2 Input Supply Current VIN = 12V, VDDQIN = 1.3V, IOUT = 3A ΔVOUT2(Line)/VOUT2 CH2 Line Regulation Accuracy VDDQIN = 1.3V, VIN = 3.6V to 15V, IOUT2 = 0A l 0.01 0.25 0.05 A ΔVOUT2(Load)/VOUT2 CH2 Load Regulation Accuracy VDDQIN = 1.3V, IOUT = –3A to 3A l 0.2 1.0 VOUT2(AC) CH2 Output Ripple Voltage IOUT = 0A, COUT = 100µF Ceramic VIN = 12V, VDDQIN = 1.3V 30 mV ΔVOUTLS2 CH2 Peak Deviation for Dynamic Load Load: 0% to 25% to 0% of Full Load COUT = 47µF Ceramic, VIN = 12V, VOUT1 = 1.3V 85 mV tSETTLE2 CH2 Settling Time for Dynamic Load Step Load: 0% to 25% to 0% of Full Load COUT = 47µF Ceramic, VIN = 12V, VOUT1 = 1.3V 20 µs IOUTPK2 CH2 Output Current Limit 4.5 A %/V % 4632fa For more information www.linear.com/LTM4632 3 LTM4632 Electrical Characteristics The l denotes the specifications that apply over the specified internal operating temperature range (Note 2). Specified as each individual output channel at TA = 25°C (Note 2), VIN = 12V, unless otherwise noted, per the typical application in Figure 19 SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS 0.593 0.600 0.607 V ±30 nA Control Section VFB1 Voltage at VFB1 Pin IOUT = 0A, VOUT1 = 1.5V IFB1 Current at VFB1 Pin (Note 4) RFBHI1 Resistor Between VOUT1 and VFB1 Pins VTTR VTTR Voltage Reference VDDQIN = 1.3V, IVTTR = ±10mA, CVTTR < 10nF VRUN1, VRUN2 RUN Pin On Threshold RUN Threshold Rising RUN Threshold Falling IRUN1, IRUN2 RUN Pin Leakage Current ITRACK/SS1 TRACK/SS1 Pin Soft-Start Pull-Up Current TRACK/SS1 = 0V 1.2 µA tON(MIN) Minimum On-Time (Note 4) 20 ns ns l l 60.00 60.40 60.80 kΩ 0.492x VDDQIN 0.50x VDDQIN 0.508x VDDQIN V 1.18 0.95 1.28 1.01 1.39 1.05 V V 0 ±1 µA tOFF(MIN) Minimum Off-Time (Note 4) 45 VPGOOD PGOOD Trip Level VFB With Respect to 0.6V VOUT2 With Respect to VDDQIN/2 (Note 4) Ramping Negative Ramping Positive –8 8 15 RPGOOD PGOOD Pull-Down Resistance 1mA Load VINTVCC Internal VCC Voltage VIN = 3.6V to 15V ICC = 0 to 50mA VINTVCC Load Reg INTVCC Load Regulation fOSC Oscillator Frequency SYNC SYNC Threshold Voltage ISYNC/MODE MODE Input Current 3.1 3.3 1.3 1 SYNC/MODE = INTVCC 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 LTM4632 is tested under pulsed load conditions such that TJ ≈ TA. The LTM4632E is guaranteed to meet performance specifications over the 0°C to 125°C internal operating temperature range. Specifications over the –40°C to 125°C internal operating temperature range are assured by design, characterization and correlation with statistical process controls. The LTM4632I is guaranteed to meet specifications over the full –40°C to 125°C internal operating temperature range. Note that the maximum ambient temperature consistent with these specifications is determined by specific operating conditions in conjunction with board layout, the rated package thermal resistance and other environmental factors. –14 14 % % Ω 3.5 V % MHz 0.95 V –1.5 µA Note 3. See output current derating curves for different VIN, VOUT and TA. Note 4. 100% tested at wafer level. Note 5. This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Junction temperature will exceed 125°C when overtemperature protection is active. Continuous operation above the specified maximum operating junction temperature may impair device reliability. 4632fa 4 For more information www.linear.com/LTM4632 LTM4632 Typical Performance Characteristics Efficiency vs Load Current at 12VIN Efficiency vs Load Current at 5VIN 100 100 95 95 95 90 90 90 85 80 75 1VOUT 1.2VOUT 1.5VOUT 1.8VOUT 2.5VOUT 70 65 60 0 0.5 1.0 2.0 1.5 LOAD CURRENT (A) 85 80 75 1VOUT 1.2VOUT 1.5VOUT 1.8VOUT 2.5VOUT 70 65 2.5 3.0 EFFICIENCY (%) 100 EFFICIENCY (%) EFFICIENCY (%) Efficiency vs Load Current at 3.6VIN 60 0 4632 G01 0.5 1.0 2.0 1.5 LOAD CURRENT (A) 85 80 75 1VOUT 1.2VOUT 1.5VOUT 1.8VOUT 2.5VOUT 70 65 2.5 3.0 60 0 4632 G02 1V Output Transient Response 1.0 2.0 1.5 LOAD CURRENT (A) 2.5 3.0 4632 G03 1.2V Output Transient Response 1.5V Output Transient Response VOUT AC-COUPLED 50mV/DIV VOUT AC-COUPLED 50mV/DIV VOUT AC-COUPLED 50mV/DIV LOAD STEP 1A/DIV LOAD STEP 1A/DIV LOAD STEP 1A/DIV 4632 G04 0.5 4632 G05 4632 G06 20µs/DIV VIN = 12V VOUT = 1V fS = 1MHz OUTPUT CAPACITOR = 1 × 47µF CERAMIC LOAD STEP = 2.25A TO 3A 20µs/DIV VIN = 12V VOUT = 1.2V fS = 1MHz OUTPUT CAPACITOR = 1 × 47µF CERAMIC LOAD STEP = 2.25A TO 3A 20µs/DIV VIN = 12V VOUT = 1.5V fS = 1MHz OUTPUT CAPACITOR = 1 × 47µF CERAMIC LOAD STEP = 2.25A TO 3A 1.8V Output Transient Response 2.5V Output Transient Response Start-Up with No Load Current Applied VOUT AC-COUPLED 50mV/DIV VOUT AC-COUPLED 50mV/DIV LOAD STEP 1A/DIV LOAD STEP 1A/DIV 4632 G07 20µs/DIV VIN = 12V VOUT = 1.8V fS = 1MHz OUTPUT CAPACITOR = 1 × 47µF CERAMIC LOAD STEP = 2.25A TO 3A SW 10V/DIV VOUT 1A/DIV IIN 0.5A/DIV 4632 G08 20µs/DIV VIN = 12V VOUT = 2.5V fS = 1MHz OUTPUT CAPACITOR = 1 × 47µF CERAMIC LOAD STEP = 2.25A TO 3A 4632 G09 20µs/DIV VIN = 12V VOUT = 1.8V fS = 1MHz IOUT = 0A INPUT CAPACITOR = 1 × 22µF CERAMIC OUTPUT CAPACITOR = 1 × 47µF CERAMIC SOFT-START CAPACITOR = 0.1µF 4632fa For more information www.linear.com/LTM4632 5 LTM4632 Typical Performance Characteristics Start-Up with 3A Load Current Applied Short-Circuit with No Load Current Applied Short-Circuit with 3A Load Current Applied SW 10V/DIV SW 10V/DIV SW 10V/DIV VOUT 1V/DIV VOUT 1V/DIV VOUT 1V/DIV IIN 2A/DIV IIN 2A/DIV IIN 0.5A/DIV 4632 G10 4632 G11 4632 G12 20ms/DIV VIN = 12V VOUT = 1.8V fS = 1MHz IOUT = 3A INPUT CAPACITOR = 1 × 22µF CERAMIC OUTPUT CAPACITOR = 1 × 47µF CERAMIC SOFT-START CAPACITOR = 0.1µF 20µs/DIV VIN = 12V VOUT = 1.8V fS = 1MHz IOUT = 0A INPUT CAPACITOR = 1 × 22µF CERAMIC OUTPUT CAPACITOR = 1 × 47µF CERAMIC 20µs/DIV VIN = 12V VOUT = 1.8V fS = 1MHz IOUT = 3A INPUT CAPACITOR = 1 × 22µF CERAMIC OUTPUT CAPACITOR = 1 × 47µF CERAMIC Recover from Short-Circuit with No Load Current Applied Steady-State Output Voltage Ripple Start-Up Into Pre-Biased Output SW 10V/DIV VOUT AC-COUPLED 50mV/DIV SW 5V/DIV SW 5V/DIV RUN 10V/DIV VOUT 1V/DIV VOUT 1V/DIV IIN 2A/DIV 20µs/DIV 4632 G13 VIN = 12V VOUT = 1.8V fS = 1MHz IOUT = 0A INPUT CAPACITOR = 1 × 22µF CERAMIC OUTPUT CAPACITOR = 1 × 47µF CERAMIC 1µs/DIV 4632 G14 VIN = 12V VOUT = 1.8V fS = 1MHz IOUT = 0A INPUT CAPACITOR = 1 × 22µF CERAMIC OUTPUT CAPACITOR = 1 × 47µF CERAMIC 50ms/DIV 4632 G15 VIN = 12V VOUT = 1.8V fS = 1MHz IOUT = 0A INPUT CAPACITOR = 1 × 22µF CERAMIC OUTPUT CAPACITOR = 1 × 47µF CERAMIC 4632fa 6 For more information www.linear.com/LTM4632 LTM4632 Pin Functions VIN (A2, B3, D3, E2): Power Input Pins. Apply input voltage between these pins and GND pins. Recommend placing input decoupling capacitance directly between VIN pins and GND pins. VOUT1 (D1, E1), VOUT2 (A1, B1): Power Output Pins of each Switching Mode Regulator. Apply output load between these pins and GND pins. Recommend placing output decoupling capacitance directly between these pins and GND pins. GND (C1-C2, C4, B5, D5): Power Ground Pins for Both Input and Output Returns. PGOOD1 (D4): Output Power Good with Open-Drain Logic of the Channel 1 Switching Mode Regulator. PGOOD1 is pulled to ground when the voltage on the FB1 pin is not within ±8% (typical) of the internal 0.6V reference. This threshold has 15mV of hysteresis. PGOOD2 (B4): Output Power Good with Open-Drain Logic of the Channel 2 Switching Mode Regulator. PGOOD2 is pulled to ground when the voltage on the VOUT2 pin is not within ±8% (typical) of the VDDQIN/2 voltage. This threshold has 15mV of hysteresis. SYNC/MODE (C5): Mode Select and External Synchronization Input. Tie this pin to ground to force continuous synchronous operation at all output loads. Floating this pin or tying it to INTVCC enables high efficiency Burst Mode operation at light loads. Drive this pin with a clock to synchronize the LTM4632 switching frequency. An internal phase-locked loop will force the bottom power NMOS’s turn on signal to be synchronized with the rising edge of the clock signal. When this pin is driven with a clock, forced continuous mode is automatically selected. INTVCC (C3): Internal 3.3V Regulator Output of the Switching Mode Regulator Channel. The internal power drivers and control circuits are powered from this voltage. This pin is internally decoupled to GND with a 2.2µF low ESR ceramic capacitor. No more external decoupling capacitor needed. COMP1 (E5), COMP2 (A5): Current Control Threshold and Error Amplifier Compensation Point of Each Switching Mode Regulator Channel. The current comparator’s trip threshold is linearly proportional to this voltage, whose normal range is from 0.3V to 1.8V. The device is internal compensated. Tie COMP pins together in Dual Phase Single Output VTT Configuration. See the Applications Information section for details. FB1 (E4): The Negative Input of the Error Amplifier for the Channel 1 Switching Mode Regulator. Internally, this pin is connected to VOUT1 with a 60.4k precision resistor. Different output voltages can be programmed with an additional resistor between FB1 and GND pins. Connect this pin to INTVCC in Dual Phase Single Output VTT Configuration. See the Applications Information section for details. TRACK/SS1 (E3): Output Tracking and Soft-Start Pin of the Channel 1 Switching Mode Regulator. It allows the user to control the rise time of the output voltage. Putting a voltage below 0.6V on this pin bypasses the internal reference input to the error amplifier, instead it servos the FB pin to the TRACK/SS voltage. Above 0.6V, the tracking function stops and the internal reference resumes control of the error amplifier. There’s an internal 1.2µA pull-up current from INTVCC on this pin, so putting a capacitor here provides a soft-start function. VTTR (A3): Reference Output. This output is used to supply the VREF voltage for DDR memory. An on-chip buffer amplifier outputs a low noise reference voltage equal to VDDQIN/2. This output is capable of supplying 10mA. VTTR has internal 0.01µF capacitor. Additional R-C filter can be used to further reduce the ripple on VTTR. The error amplifier for channel 2 uses this voltage as its reference voltage. VDDQIN (A4): External Reference Input for Channel 2. An internal resistor divider sets the VTTR pin voltage to be equal to half the voltage applied to this input. Channel 2 uses the VTTR pin voltage as its error amplifier reference. RUN1 (D2), RUN2 (B2): Run Control Input of Each Switching Mode Regulator Channel. Enables chip operation by tying RUN above 1.28V. Tying this pin below 1V shuts down the specific regulator channel. Do not float this pin. 4632fa For more information www.linear.com/LTM4632 7 LTM4632 Block Diagram VDDQ VOUT1 60.4k FB1 51.7k VDDQIN VOUT2 VTTR BUFFER PGOOD1 10k PGOOD2 10k INTVCC INTVCC 0.01µF INTVCC VIN 2.2µF 0.22µF 10µF SYNC/MODE TRACK/SS1 0.82µH VDDQ 1.3V 3A VOUT1 0.1µF VIN 3.6V TO 15V 1µF 22µF GND RUN1 RUN2 COMP1 0.22µF POWER CONTROL INTERNAL COMP 0.82µH VTT 0.65V ±3A VOUT2 1µF COMP2 22µF GND INTERNAL COMP FREQ 312k SGND 4632 BD Decoupling Requirements SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS CIN External Input Capacitor Requirement (VIN = 3.6V to 15V, VOUT = 1.5V) IOUT = 3A 4.7 10 µF COUT External Output Capacitor Requirement (VIN = 3.6V to 15V, VOUT = 1.5V) IOUT = 3A 10 22 µF 4632fa 8 For more information www.linear.com/LTM4632 LTM4632 Operation The LTM4632 is a dual output standalone non-isolated switch mode DC/DC power supply for DDR-QDR4 SRAM memory supplies and bus termination. It can deliver two output rails which could both sink and source 3A DC current with few external input and output ceramic capacitors, plus a 10mA buffered VTTR (VREF) reference voltage which equal to one half of VDDQIN voltage. Two or more module outputs can be easily paralleled to achieve a single VTT output with a higher sink and source current capability. Up to 8 phases can be paralleled to run simultaneously with a good current sharing guaranteed by current mode control loop. This module provides precisely regulated output voltage (VOUT1) programmable via one external resistor from 0.6V to 2.5V over 3.6V to 15V input voltage range. With INTVCC tied to VIN, this module is able to operate from 3.3V input. The LTM4632 has an integrated a dual constant on-time valley current mode regulator, power MOSFETs, inductor, and other supporting discrete components. The typical switching frequency is internally set to 1MHz. For switching noise-sensitive applications, the µModule can be externally synchronized to a clock within ±30% of the set frequency. See the Applications Information section. With current mode control and internal feedback loop compensation, the LTM4632 module has sufficient stability margins and good transient performance with a wide range of output capacitors, even with all ceramic output capacitors. Current mode control provides cycle-by-cycle fast current limiting. An internal overvoltage and undervoltage comparators pull the open-drain PGOOD output low if the output feedback voltage exits a ±8% window around the regulation point. Furthermore, an input overvoltage protection been utilized by shutting down both power MOSFETs when VIN rises above 17.5V to protect internal devices. Pulling the RUN pin below 1V forces the controller into its shutdown state, turning off both power MOSFETs and most of the internal control circuitry. At light load currents, burst mode operation can be enabled to achieve higher efficiency compared to continuous mode (CCM) by setting MODE pin to INTVCC. The TRACK/SS pin is used for power supply tracking and soft-start programming. See the Applications Information section. Applications Information The typical LTM4632 application circuit is shown in Figure 19. External component selection is primarily determined by the input voltage, the output voltage and the maximum load current. Refer to Table 5 for specific external capacitor requirements for a particular application. VIN to VOUT Step-Down Ratios There are restrictions in the maximum VIN and VOUT step down ratio that can be achieved for a given input voltage due to the minimum off-time and minimum on-time limits of the regulator. The minimum off-time limit imposes a maximum duty cycle which can be calculated as: DMAX = 1 – tOFF(MIN) • fSW where tOFF(MIN) is the minimum off-time, 45ns typical for LTM4632, and fSW is the switching frequency. Conversely the minimum on-time limit imposes a minimum duty cycle of the converter which can be calculated as DMIN = tON(MIN) • fSW where tON(MIN) is the minimum on-time, 20ns typical for LTM4632. In the rare cases where the minimum duty cycle is surpassed, the output voltage will still remain in regulation, but the switching frequency will decrease from its programmed value. Note that additional thermal derating may be applied. See the Thermal Considerations and Output Current Derating section in this data sheet. 4632fa For more information www.linear.com/LTM4632 9 LTM4632 Applications Information Channel 1 Output Voltage Programming (Configured as VDDQ) The PWM controller for the VOUT1 has an internal 0.6V reference voltage. As shown in the Block Diagram, a 60.4k internal feedback resistor connects VOUT1 and FB1 pins together. Adding a resistor RFB from FB1 pin to GND programs the output voltage: RFB = 0.6V • 60.4k VOUT – 0.6V RFB(k) ICIN(RMS) = IOUT(MAX) η% • D•(1–D) where η% is the estimated efficiency of the power module. Output Decoupling Capacitors Table 1. VFB Resistor Table (1%) vs Various Output Voltages VOUT(V) Without considering the inductor current ripple, for each output, the RMS current of the input capacitor can be estimated as: 0.6 1.0 1.2 1.3 1.5 1.8 2.5 OPEN 90.9 60.4 52.3 40.2 30.1 19.1 Channel 2 Output Voltage Programming (Configured as VTT) The PWM controller for the VOUT2 uses VTTR voltage as a reference voltage. VOUT2 is directly connected to the negative side of the error compiler to internally program VOUT2 to equal to VTTR voltage, which equals to one half of VDDQIN voltage. VOUT2 = VTTR = VDDQIN/2 In a complete DDR memory power application which require both VDDQ supply and VTT terminal outputs, configure LTM4632 Channel 1 as VDDQ output by adding a feed-back resistor from FB1 pin to GND. Feed VOUT1 (VDDQ output) voltage to VDDQIN pin to program Channel 2 as VTT output which equals half of the Channel 1 (VDDQ output) voltage. Input Decoupling Capacitors The LTM4632 module should be connected to a low acimpedance DC source. For each regulator channel, one piece 4.7µF input ceramic capacitor is required for RMS ripple current decoupling. Bulk input capacitor is only needed when the input source impedance is compromised by long inductive leads, traces or not enough source capacitance. The bulk capacitor can be an electrolytic aluminum capacitor and polymer capacitor. With an optimized high frequency, high bandwidth design, only single piece of 22µF low ESR output ceramic capacitor is required for each LTM4632 output to achieve low output voltage ripple and very good transient response. Additional output filtering may be required by the system designer, if further reduction of output ripples or dynamic transient spikes is required. Table 5 shows a matrix of different output voltages and output capacitors to minimize the voltage droop and overshoot during a 0.75A (25%) load step transient. Multiphase operation will reduce effective output ripple as a function of the number of phases. Application Note 77 discusses this noise reduction versus output ripple current cancellation, but the output capacitance will be more a function of stability and transient response. The Linear Technology LTpowerCAD Design Tool is available to download online for output ripple, stability and transient response analysis and calculating the output ripple reduction as the number of phases implemented increases by N times. Burst Mode Operation In applications where high efficiency at intermediate current are more important than output voltage ripple, burst mode operation could be used on Channel 1 by connecting SYNC/MODE pin to INTVCC to improve light load efficiency. In Burst Mode operation, a current reversal comparator (IREV) detects the negative inductor current and shuts off the bottom power MOSFET, resulting in discontinuous operation and increased efficiency. Both power MOSFETs will remain off and the output capacitor will supply the load current until the COMP voltage rises above the zero current level to initiate another cycle. 4632fa 10 For more information www.linear.com/LTM4632 LTM4632 Applications Information Force Continuous Current Mode (CCM) Operation In applications where fixed frequency operation is more critical than low current efficiency, and where the lowest output ripple is desired, forced continuous operation should be used. Forced continuous operation can be enabled by tying the SYNC/MODE pin to GND. In this mode, inductor current is allowed to reverse during low output loads, the COMP voltage is in control of the current comparator threshold throughout, and the top MOSFET always turns on with each oscillator pulse. During start-up, forced continuous mode is disabled and inductor current is prevented from reversing until the LTM4632’s output voltage is in regulation. The two switching mode regulator channels inside the LTM4632 are internally set to operate 180° out of phase. Multiple LTM4632s could easily operate 90 degrees, 60 degrees or 45 degrees shift which corresponds to 4-phase, 6-phase or 8-phase operation by letting SYNC/MODE of the LTM4632 synchronize to an external multiphase oscillator like LTC6902. Figure 2 shows a 4-phase single output VTT termination supply design example for clock phasing. 33.2k 3.3 INTVCC V+ SET PH MOD LTC6902 Operating Frequency The operating frequency of the LTM4632 is optimized to achieve the compact package size and the minimum output ripple voltage while still keeping high efficiency. The default operating frequency is internally set to 1MHz. In most applications, no additional frequency adjusting is required. Frequency Synchronization The power module has a phase-locked loop comprised of an internal voltage controlled oscillator and a phase detector. This allows the internal top MOSFET turn-on to be locked to the rising edge of the external clock. The external clock frequency range must be within ±30% around the set operating frequency. A pulse detection circuit is used to detect a clock on the SYNC/MODE pin to turn on the phase locked loop. The pulse width of the clock has to be at least 100ns. The clock high level must be above 2V and clock low level below 0.3V. The presence of an external clock will place both regulator channels into forced continuous mode operation. During the start-up of the regulator, the phase-locked loop function is disabled. Multiphase Operation (Configured as Multiphase Single Output VTT) For VTT termination output loads that demand more than 3A of current, two outputs in the LTM4632 or even multiple LTM4632s can be paralleled to run out of phase to provide a multiphase single output VTT termination supply capable of souring and sinking higher current. DIV OUT1 GND OUT2 LTM4632 0° VOUT1 SYNC/ MODE 0° 90° VOUT2 180° VTT 12A LTM4632 90° VOUT1 SYNC/ MODE VOUT2 270° 4632 F02 Figure 2. Example of Clock Phasing for 4-Phase Single Output VTT Operation with LTC6902 Tie FB1 pin of the LTM4632 to its INTVCC pin to put the module into two phase single VTT output operation mode. This will internally switch the Channel 1 error amplifier reference voltage from 0.6V to VTTR voltage, which is the same as Channel 2. Repeat this for each LTM4632 module in multiple LTM4632s paralleling application. Also tie RUN, TRACK/SS and COMP pin of each paralleling channel together. Figure 20 shows an example of paralleled multiphase single output VTT termination supply operation and pin connection. The LTM4632 device is an inherently current mode controlled device, so parallel modules will have very good current sharing. This will balance the thermals on the design. Multiphase Operation (Configured as VDDQ+VTT) For application which both VDDQ and VTT termination output loads demand more than 3A of current, two or multiple Channel 1 outputs from different LTM4632 modules can be easily paralleled to provide a multiphase single VDDQ output while Channel 2 outputs from different LTM4632 modules can paralleled to provide a multiphase single VTT output. 4632fa For more information www.linear.com/LTM4632 11 LTM4632 Applications Information In this case, multiple LTM4632s should be setup to operate 180 degrees, 120 degrees or 90 degrees shift which corresponds to 2-phase, 3-phase or 4-phase operation by letting SYNC/MODE of the LTM4632 synchronize to an external multiphase oscillator like LTC6902. 33.2k 3.3 INTVCC V+ SET PH MOD DIV OUT1 GND OUT2 SYNC/ MODE VOUT1 SYNC/ MODE VOUT1 VOUT2 0° 180° VOUT2 0° VDDQ 6A 180° VTT 6A 180° 360° 4632 F03 Figure 3. Example of Clock Phasing for 2-Phase VDDQ Plus 2-Phase VTT Operation with LTC6902 Tie RUN1, TRACK/SS1 FB1 and COMP1 pin of each paralleling module together for VDDQ output. Tie RUN2, VDDQIN, FB2 and COMP2 pin of each paralleling module together for VTT output. Figure 22 shows an example of two LTM4632 get paralleled to provide 6A VDDQ and 6A VTT termination supply. Input and Output RMS Ripple Current Cancellation A multiphase power supply significantly reduces the amount of ripple current in both the input and output capacitors. The RMS input ripple current is reduced by, and the effective ripple frequency is multiplied by, the number of phases used (assuming that the input voltage is greater than the number of phases used times the output voltage). The output ripple amplitude is also reduced by the number of phases used when all of the outputs are tied together to achieve a single high output current design. 0.60 1-PHASE 2-PHASE 3-PHASE 4-PHASE 6-PHASE 0.55 0.50 RMS INPUT RIPPLE CURRENT DC LOAD CURRENT 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 DUTY CYCLE (VOUT/VIN) 4632 F04 Figure 4. Input RMS Current Ratios to DC Load Current as a Function of Duty Cycle 4632fa 12 For more information www.linear.com/LTM4632 LTM4632 Applications Information Channel 1 Output Voltage Tracking and Soft-Start The TRACK/SS pin provides a means to either soft-start the Channel 1 regulator or track it to a different power supply. A capacitor on the TRACK/SS pin will program the ramp rate of the channel 1 output voltage. An internal 1.2µA current source will charge up the external soft-start capacitor towards INTVCC voltage. When the TRACK/SS voltage is below 0.6V, it will take over the internal 0.6V reference voltage to control the output voltage. The total soft-start time can be calculated as: t = 0.6 • CSS SS 1.2µA where CSS is the capacitance on the TRACK/SS pin. Forced continuous mode are disabled during the soft-start process. Channel 1 output voltage tracking can also be programmed externally using the TRACK/SS pin. The output can be tracked up and down with another regulator. Figure 5 and Figure 6 show an example waveform and schematic of a Ratiometric tracking where the slave regulator’s output slew rate is proportional to the master’s. Since the slave regulator’s TRACK/SS is connected to the master’s output through a RTR(TOP)/RTR(BOT) resistor divider and its voltage used to regulate the slave output voltage when TRACK/SS voltage is below 0.6V, the slave output voltage and the master output voltage should satisfy the following equation during the start-up. VOUT(SL) • RFB(SL) RFB(SL) +60.4k VOUT(MA) • = R TR(TOP) The RFB(SL) is the feedback resistor and the RTR(TOP)/ RTR(BOT) is the resistor divider on the TRACK/SS pin of the slave regulator, as shown in Figure 6. Following the upper equation, the master’s output slew rate (MR) and the slave’s output slew rate (SR) in Volts/ Time is determined by: MR = SR RFB(SL) RFB(SL) +60.4k R TR(TOP) R TR(TOP) +R TR(BOT) For example, VOUT(MA) = 1.5V, MR = 1.5V/1ms and VOUT(SL) = 1.2V, SR = 1.2V/1ms. From the equation, we could solve out that RTR(TOP) = 60.4k and RTR(BOT) = 40.2k is a good combination for the Ratiometric tracking. MASTER OUTPUT OUTPUT VOLTAGE Application Note 77 provides a detailed explanation of multiphase operation. The input RMS ripple current cancellation mathematical derivations are presented, and a graph is displayed representing the RMS ripple current reduction as a function of the number of interleaved phases. Figure 4 shows this graph. SLAVE OUTPUT TIME 4632 F05 Figure 5. Output Ratiometric Tracking Waveform The TRACK pins will have the 1.2µA current source on when a resistive divider is used to implement tracking on that specific channel. This will impose an offset on the TRACK pin input. Smaller values resistors with the same ratios as the resistor values calculated from the above equation can be used. For example, where the 60.4k is used then a 6.04k can be used to reduce the TRACK pin offset to a negligible value. R TR(TOP) +R TR(BOT) 4632fa For more information www.linear.com/LTM4632 13 LTM4632 Applications Information PGOOD1 VIN 3.6V TO 15V RAIL 10µF 16V PGOOD2 VIN VOUT1 RUN1 VOUT2 RUN2 COMP1 TRACK/SS1 COMP2 40.2k VDDQIN GND PGOOD2 VIN VOUT1 RUN1 VOUT2 RUN2 INTVCC 60.4k 40.2k FB1 SYNC/MODE PGOOD1 VOUT1 VOUT2 1.2V, 3A 22µF 4V VTTR LTM4632 FB1 SYNC/MODE COMP1 TRACK/SS1 COMP2 VDDQIN 22µF 4V VTTR LTM4632 INTVCC 0.1µF VOUT1 1.5V, 3A 60.4k GND 4632 F06 Figure 6. Example Schematic of Ratiometric Output Voltage Tracking From the equation, we could easily find out that, in the Coincident tracking, the slave regulator’s TRACK/SS pin resistor divider is always the same as its feedback divider. RFB(SL) = MASTER OUTPUT OUTPUT VOLTAGE The Coincident output tracking can be recognized as a special Ratiometric output tracking which the master’s output slew rate (MR) is the same as the slave’s output slew rate (SR), as waveform shown in Figure 7. SLAVE OUTPUT R TR(TOP) RFB(SL) +60.4k R TR(TOP) +R TR(BOT) TIME 4632 F07 Figure 7. Output Coincident Tracking Waveform 4632fa 14 For more information www.linear.com/LTM4632 LTM4632 Applications Information For example, RTR(TOP) = 60.4k and RTR(BOT) = 60.4k is a good combination for Coincident tracking for VOUT(MA) = 1.5V and VOUT(SL) = 1.2V application. Power Good The PGOOD pins are open drain pins that can be used to monitor valid output voltage regulation. This pin monitors a ±8% window around the regulation point. A resistor can be pulled up to a particular supply voltage for monitoring. To prevent unwanted PGOOD glitches during transients or dynamic VOUT changes, the LTM4632’s PGOOD falling edge includes a blanking delay of approximately 40us. Stability Compensation The LTM4632 module internal compensation loop is de-signed and optimized for low ESR ceramic output capacitors only application. Table 5 is provided for most application requirements. The LTpowerCAD Design Tool is available to download for control loop analysis for further optimization. RUN Enable Pulling the RUN pin to ground forces the LTM4632 into its shutdown state, turning off both power MOSFETs and most of its internal control circuitry. Trying the RUN pin voltage above 1.28V will turn on the entire chip. Low Input Application The LTM4632 is capable to run from 3.3V input when the VIN pin is tied to INTVCC pin. See Figure 21 for the application circuit. Please note the INTVCC pin has 3.6V abs max voltage rating. Pre-Biased Output Start-Up (Channel 1) There may be situations that require the power supply to start up with a pre-bias on the output capacitors. In this case, it is desirable to start up without discharging that output pre-bias. The LTM4632 channel 1 can safely power up into a pre-biased output without discharging it. The LTM4632 accomplishes this by forcing discontinuous mode (DCM) operation until the TRACK/SS1 pin voltage reaches 80% of the 0.6V reference voltage for channel 1. This will prevent the BG from turning on during the prebiased output start-up which would discharge the output. Do not pre-bias LTM4632 with a voltage higher than INTVCC (3.3V) voltage. Overtemperature Protection The internal overtemperature protection monitors the junction temperature of the module. If the junction temperature reaches approximately 170°C, both power switches will be turned off until the temperature drops about 10°C cooler. Input Overvoltage Protection In order to protect the internal power MOSFET devices against transient voltage spikes, the LTM4632 constantly monitors each VIN pin for an overvoltage condition. When VIN rises above 17.5V, the regulator suspends operation by shutting off both power MOSFETs on the corresponding channel. Once VIN drops below 16.5V, the regulator immediately resumes normal operation. The regulator executes its soft-start function when exiting an overvoltage condition. Thermal Considerations and Output Current Derating The thermal resistances reported in the Pin Configuration section of the data sheet are consistent with those parameters defined by JESD51-9 and are intended for use with finite element analysis (FEA) software modeling tools that leverage the outcome of thermal modeling, simulation, and correlation to hardware evaluation performed on a µModule package mounted to a hardware test board—also defined by JESD51-9 (“Test Boards for Area Array Surface Mount Package Thermal Measurements”). The motivation for providing these thermal coefficients in found in JESD51-12 (“Guidelines for Reporting and Using Electronic Package Thermal Information”). Many designers may opt to use laboratory equipment and a test vehicle such as the demo board to anticipate the µModule regulator’s thermal performance in their application at various electrical and environmental operating conditions to compliment any FEA activities. Without FEA software, the thermal resistances reported in the Pin Configuration section are in-and-of themselves not relevant to providing guidance of thermal performance; instead, the 4632fa For more information www.linear.com/LTM4632 15 LTM4632 Applications Information derating curves provided in the data sheet can be used in a manner that yields insight and guidance pertaining to one’s application-usage, and can be adapted to correlate thermal performance to one’s own application. A graphical representation of the aforementioned thermal resistances is given in Figure 8; blue resistances are contained within the μModule regulator, whereas green resistances are external to the µModule package. The Pin Configuration section typically gives four thermal coefficients explicitly defined in JESD 51-12; these coefficients are quoted or paraphrased below: As a practical matter, it should be clear to the reader that no individual or sub-group of the four thermal resistance parameters defined by JESD51-12 or provided in the Pin Configuration section replicates or conveys normal operating conditions of a μModule. For example, in normal board-mounted applications, never does 100% of the device’s total power loss (heat) thermally conduct exclusively through the top or exclusively through bottom of the µModule package as the standard defines for θJCtop and θJCbottom, respectively. In practice, power loss is thermally dissipated in both directions away from the package–granted, in the absence of a heat sink and airflow, a majority of the heat flow is into the board. 1.θJA, the thermal resistance from junction to ambient, is the natural convection junction-to-ambient air thermal resistance measured in a one cubic foot sealed enclosure. This environment is sometimes referred to as “still air” although natural convection causes the air to move. This value is determined with the part mounted to a JESD 51-9 defined test board, which does not reflect an actual application or viable operating condition. 2.θJCbottom, the thermal resistance from junction to ambient, is the natural convection junction-to-ambient air thermal resistance measured in a one cubic foot sealed enclosure. This environment is sometimes referred to as “still air” although natural convection causes the air to move. This value is determined with the part mounted to a JESD 51-9 defined test board, which does not reflect an actual application or viable operating condition. 3.θJCtop, the thermal resistance from junction to top of the product case, is determined with nearly all of the component power dissipation flowing through the top of the package. As the electrical connections of the typical µModule are on the bottom of the package, it is rare for an application to operate such that most of the heat flows from the junction to the top of the part. As in the case of θJCbottom, this value may be useful for comparing packages but the test conditions don’t generally match the user’s application. 4.θJB, the thermal resistance from junction to the printed circuit board, is the junction-to-board thermal resistance where almost all of the heat flows through the bottom of the µModule and into the board, and is really the sum of the θJCbottom and the thermal resistance of the bottom of the part through the solder joints and through a portion of the board. The board temperature is measured a specified distance from the package, using a two sided, two layer board. This board is described in JESD 51-9. Within a SIP (system-in-package) module, be aware there are multiple power devices and components dissipating power, with a consequence that the thermal resistances relative to different junctions of components or die are not exactly linear with respect to total package power loss. To reconcile this complication without sacrificing modeling simplicity–but also, not ignoring practical realities–an approach has been taken using FEA software modeling along with laboratory testing in a controlled-environment chamber to reasonably define and correlate the thermal resistance values supplied in this data sheet: (1) Initially, FEA software is used to accurately build the mechanical geometry of the µModule and the specified PCB with all of the correct material coefficients along with accurate power loss source definitions; (2) this model simulates a softwaredefined JEDEC environment consistent with JESD51-12 to predict power loss heat flow and temperature readings at different interfaces that enable the calculation of the JEDEC-defined thermal resistance values; (3) the model and FEA software is used to evaluate the µModule with heat sink and airflow; (4) having solved for and analyzed these thermal resistance values and simulated various operating conditions in the software model, a thorough laboratory evaluation replicates the simulated conditions with thermocouples within a controlled-environment chamber while operating the device at the same power loss as that 4632fa 16 For more information www.linear.com/LTM4632 LTM4632 Applications Information which was simulated. The outcome of this process and due diligence yields the set of derating curves provided in other sections of this data sheet. After these laboratory test have been performed and correlated to the µModule model, then the θJB and θBA are summed together to correlate quite well with the µModule model with no airflow or heat sinking in a properly define chamber. This θJB + θBA value is shown in the Pin Configuration section and should accurately equal the θJA value because approximately 100% of power loss flows from the junction through the board into ambient with no airflow or top mounted heat sink. The 1.0V, 1.5V, and 2.5V power loss curves in Figures 9 to 11 can be used in coordination with the load current derating curves in Figures 12 to 17 for calculating an approximate θJA thermal resistance for the LTM4632 with no heat sinking and various airflow conditions. The power loss curves are taken at room temperature, and are increased with multiplicative factors of 1.35 assuming junction temperature at 120°C. The derating curves are plotted with the output current starting at 6A by putting LTM4632 into two phase single output setup (Figure 20) and the ambient temperature at 40°C. These output voltages are chosen to include the lower and higher output voltage ranges for correlating the thermal resistance. Thermal models are derived from several temperature measurements in a controlled temperature chamber along with thermal modeling analysis. The junction temperatures are monitored while ambient temperature is increased with and without airflow. The power loss increase with ambient temperature change is factored into the derating curves. The junctions are maintained at 120°C maximum while lowering output current or power with increasing ambient temperature. The decreased output current will decrease the internal module loss as ambient temperature is increased. The monitored junction temperature of 120°C minus the ambient operating temperature specifies how much module temperature rise can be allowed. As an example in Figure 12 the load current is derated to ~3A at ~100°C with no air or heat sink and the power loss for the 5V to 1V at 3A output is about 0.95W. The 0.95W loss is calculated with the ~0.7W room temperature loss from the 5V to 1V power loss curve at 3A, and the 1.35 multiplying factor at 120°C measured junction temperature. If the 100°C ambient temperature is subtracted from the 120°C junction temperature, then the difference of 20°C divided by 0.95W equals a 20°C/W θJA thermal resistance. Table 2 specifies a 19°C~20°C/W value which is very close. Table 2 to 4 provide equivalent thermal resistances for 1.0V, 1.5V, and 2.5V outputs with and without airflow. The derived thermal resistances in Table 2 to 4 for the various conditions can be multiplied by the calculated power loss as a function of ambient temperature to derive temperature rise above ambient, thus maximum junction temperature. Room temperature power loss can be derived from the efficiency curves in the Typical Performance Characteristics section and adjusted with the above ambient temperature multiplicative factors. The printed circuit board is a 1.6mm thick four layer board with two ounce copper for the two outer layers and one ounce copper for the two inner layers. The PCB dimensions are 95mm × 76mm. JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD) JUNCTION-TO-CASE (TOP) RESISTANCE JUNCTION CASE (TOP)-TO-AMBIENT RESISTANCE JUNCTION-TO-BOARD RESISTANCE JUNCTION-TO-CASE CASE (BOTTOM)-TO-BOARD (BOTTOM) RESISTANCE RESISTANCE AMBIENT BOARD-TO-AMBIENT RESISTANCE 4638 F08 µMODULE DEVICE Figure 8. Graphical Representation of JESD51-12 Thermal Coefficients 4632fa For more information www.linear.com/LTM4632 17 LTM4632 Applications Information Figure 10. 1.5V Output Power Loss 3.6 3.6 3.6 3.2 3.2 3.2 2.8 2.8 2.8 2.4 2.0 1.6 1.2 12VIN 2.4 2.0 1.6 12VIN 1.2 0.8 0.4 0 POWER LOSS (W) 4.0 0.8 0.4 5VIN 0 1 3 2 4 LOAD CURRENT (A) 5 0 6 2.0 1.6 0.4 5VIN 0 1 3 2 4 LOAD CURRENT (A) 5 0 6 Figure 13. 12V to 1.0V Derating Curve, No Heat Sink 6 6 5 5 5 0LFM 200LFM 400LFM 1 0 30 40 LOAD CURRENT (A) 6 LOAD CURRENT (A) 7 2 4 3 2 0LFM 200LFM 400LFM 1 0 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 30 40 2 0 6 5 5 5 0 30 40 LOAD CURRENT (A) 6 LOAD CURRENT (A) 6 0LFM 200LFM 400LFM 2 0LFM 200LFM 400LFM 1 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 4632 F15 30 40 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) Figure 17. 12V to 2.5V Derating Curve, No Heat Sink 7 1 0LFM 200LFM 400LFM 4632 F14 7 3 0 30 40 4 3 2 0LFM 200LFM 400LFM 1 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 4632 F16 6 3 Figure 16. 5V to 2.5V Derating Curve, No Heat Sink 4 5 4 7 2 3 2 4 LOAD CURRENT (A) 4632 F13 Figure 15. 12V to 1.5V Derating Curve, No Heat Sink 3 1 1 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 4632 F12 4 0 Figure 14. 5V to 1.5V Derating Curve, No Heat Sink 7 3 5VIN 4632 F11 7 4 12VIN 1.2 4632 F10 Figure 12. 5V to 1.0V Derating Curve, No Heat Sink LOAD CURRENT (A) 2.4 0.8 4632 F09 LOAD CURRENT (A) Figure 11. 2.5V Output Power Loss 4.0 POWER LOSS (W) POWER LOSS (W) Figure 9. 1.0V Output Power Loss 4.0 0 30 40 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 4632 F17 4632fa 18 For more information www.linear.com/LTM4632 LTM4632 Applications Information Table 2. 1.0V Output DERATING CURVE Figures 12, 13 VIN (V) POWER LOSS CURVE AIR FLOW (LFM) HEAT SINK θJA (°C/W) 5, 12 Figure 9 0 None 19 to 20 Figures 12, 13 5, 12 Figure 9 200 None 18 to 19 Figures 12, 13 5, 12 Figure 9 400 None 17 to 18 Table 3. 1.5V Output VIN (V) POWER LOSS CURVE AIR FLOW (LFM) HEAT SINK θJA (°C/W) Figures 14, 15 DERATING CURVE 5, 12 Figure 10 0 None 19 to 20 Figures 14, 15 5, 12 Figure 10 200 None 18 to 19 Figures 14, 15 5, 12 Figure 10 400 None 17 to 18 VIN (V) POWER LOSS CURVE AIR FLOW (LFM) HEAT SINK θJA (°C/W) 5, 12 Figure 11 0 None 19 to 20 Table 4. 2.5V Output DERATING CURVE Figures 16, 17 Figures 16, 17 5, 12 Figure 11 200 None 18 to 19 Figures 16, 17 5, 12 Figure 11 400 None 17 to 18 4632fa For more information www.linear.com/LTM4632 19 LTM4632 Applications Information Table 5. Output Voltage Response for Each Regulator Channel vs Component Matrix (Refer to Figure 19) 25% Load Step Typical Measured Values CIN (CERAMIC) PART NUMBER COUT1 (CERAMIC) PART NUMBER VALUE COUT2 (BULK) VALUE Murata GRM188R61E475KE11# 4.7µF, 25V, 0603, X5R Murata GRM21R60J476ME15# Murata GRM188R61E106MA73# 10µF, 25V, 0603, X5R Murata GRM188R60J226MEA0# 22µF, 6.3V, 0603, X5R Taiyo Yuden JMK212BJ476MG-T Taiyo Yuden TMK212BJ475KG-T VOUT (V) 4.7µF, 25V, 0805, X5R CIN COUT1 (CERAMIC) CIN (CERAMIC) (µF) (µF) (BULK) 47µF, 6.3V, 0805, X5R PART NUMBER VALUE Panasonic 6TPC150M 150µF, 6.3V 3.5 × 2.8 × 1.4mm 47µF, 6.3V, 0805, X5R COUT2 (BULK) (µF) CFF (pF) VIN (V) DROOP (mV) P-P DERIVATION (mV) RECOVERY TIME (µS) LOAD STEP (A) LOAD STEP SLEW RATE (A/µS) RFB (kΩ) 1 2 × 10 0 1 × 47µF 0 0 5, 12 0 77 15 0.75 10 90.9 1.2 2 × 10 0 1 × 47µF 0 0 5, 12 0 83 15 0.75 10 60.4 1.5 2 × 10 0 1 × 47µF 0 0 5, 12 0 94 18 0.75 10 40.2 1.8 2 × 10 0 1 × 47µF 0 0 5, 12 0 105 20 0.75 10 30.1 2.5 2 × 10 0 1 × 47µF 0 0 5, 12 0 138 20 0.75 10 19.1 4632fa 20 For more information www.linear.com/LTM4632 LTM4632 Applications Information SAFETY CONSIDERATIONS The LTM4632 modules do not provide galvanic isolation from VIN to VOUT. There is no internal fuse. If required, a slow blow fuse with a rating twice the maximum input current needs to be provided to protect each unit from catastrophic failure. The device does support thermal shutdown and over current protection. LAYOUT CHECKLIST/EXAMPLE The high integration of LTM4632 makes the PCB board layout very simple and easy. However, to optimize its electrical and thermal performance, some layout considerations are still necessary. • Use large PCB copper areas for high current paths, including VIN, GND, VOUT1 and VOUT2. It helps to minimize the PCB conduction loss and thermal stress. • Place high frequency ceramic input and output capacitors next to the VIN, PGND and VOUT pins to minimize high frequency noise. • Place a dedicated power ground layer underneath the unit. • To minimize the via conduction loss and reduce module thermal stress, use multiple vias for interconnection between top layer and other power layers. • Do not put via directly on the pad, unless they are capped or plated over. • Use a separated SGND ground copper area for components connected to signal pins. Connect the SGND to GND underneath the unit. • For parallel modules, tie the VOUT, VFB, and COMP pins together. Use an internal layer to closely connect these pins together. The TRACK pin can be tied a common capacitor for regulator soft-start. • Bring out test points on the signal pins for monitoring. Figure 18 gives a good example of the recommended layout. GND COUT COUT VIN VIN CIN CIN GND Figure 18. Recommend PCB Layout 4632fa For more information www.linear.com/LTM4632 21 LTM4632 Applications Information VIN 3.6V TO 15V RAIL 22µF 25V VDDQ 22µF 4V PGOOD1 PGOOD2 VOUT1 VIN RUN1 RUN2 LTM4632 VOUT2 INTVCC VTTR SYNC/MODE FB1 COMP1 TRACK/SS1 VDDQIN 22µF 4V VDDQ 1.3V, 3A VTT 0.65V, ±3A VTTR 0.65V, 10mA COMP2 GND 52.3k 4632 F19 Figure 19. 3.6V to 15V Input, 1.5V/3A VDDQ, 0.75V/±3A VTT and 10mA VTTR Design VIN 4V TO 15V RAIL VIN LTM4630 22µF 25V ×4 22µF 25V VDDQ VOUT1 VOUT2 100µF 4V ×6 GND PGOOD1 PGOOD2 VOUT1 VIN RUN1 VOUT2 RUN2 LTM4632 VTTR INTVCC FB1 SYNC/MODE COMP1 TRACK/SS1 VDDQIN VDDQ 1.8V, 36A 47µF 4V VTT 0.9V, ±6A INTVCC COMP2 VTTR 0.9V, 10mA GND 4632 F20 Figure 20. 4V to 15V Input, Two Phase Single Output ±6A VTT Termination Design with LTM4630 36A VDDQ Supply 4632fa 22 For more information www.linear.com/LTM4632 LTM4632 Applications Information VIN 3.1V TO 3.5V RAIL 22µF 6.3V VDDQ 22µF 4V PGOOD1 PGOOD2 VOUT1 VIN RUN1 RUN2 LTM4632 VOUT2 INTVCC VTTR SYNC/MODE FB1 COMP1 TRACK/SS1 VDDQIN 22µF 4V VDDQ 1.5V, 3A VTT 0.75V, ±3A VTTR 0.75V, 10mA COMP2 GND 40.2k 4632 F21 Figure 21. 3.3V Input, 1.5V/3A VDDQ, 0.75V/±3A VTT and 10mA VTTR Design VIN 3.6V TO 15V RAIL 22µF 25V 33.2k 1 INTVCC 1µF 2 3 4 5 V+ LTC6902 SET DIV MOD PH GND OUT1 OUT4 OUT2 OUT3 INTVCC 22µF 4V PGOOD1 PGOOD2 VIN VOUT1 RUN1 VOUT2 RUN2 LTM4632 VTTR INTVCC FB1 SYNC/MODE COMP1 TRACK/SS1 COMP2 VDDQIN VDDQ 1.2V, 6A VTT 22µF 0.6V, ±6A 4V VTTR 0.6V, 10mA GND 10 9 8 7 6 PGOOD1 PGOOD2 VIN VOUT1 RUN1 VOUT2 RUN2 LTM4632 VTTR INTVCC FB1 SYNC/MODE VDDQ TRACK/SS1 VDDQIN COMP1 COMP2 GND 30.2k 4632 F22 Figure 22. Two Module in Parallel, 3.6V to 15V Input, 1.2V/6A VDDQ, 0.6V/±6A VTT and 10mA VTTR Design 4632fa For more information www.linear.com/LTM4632 23 LTM4632 Package Description PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY. LTM4632 Component LGA and BGA Pinout PIN ID FUNCTION PIN ID FUNCTION PIN ID FUNCTION PIN ID FUNCTION PIN ID FUNCTION A1 VOUT2 A2 VIN A3 VTTR A4 VDDQIN A5 COMP2 B1 VOUT2 B2 RUN2 B3 VIN B4 PGOOD2 B5 GND C1 GND C2 GND C3 INTVCC C4 SGND C5 SYNC/MODE D1 VOUT1 D2 RUN1 D3 VIN D4 PGOOD1 D5 GND E1 VOUT1 E2 VIN E3 TRACK/SS1 E4 FB1 E5 COMP1 4632fa 24 For more information www.linear.com/LTM4632 0.000 For more information www.linear.com/LTM4632 2.540 1.270 0.3175 0.3175 1.270 2.540 SUGGESTED PCB LAYOUT TOP VIEW 2.540 PACKAGE TOP VIEW 1.270 4 0.3175 0.000 0.3175 PIN “A1” CORNER E 1.270 aaa Z 2.540 Y D X aaa Z // bbb Z SYMBOL A b D E e F G H1 H2 aaa bbb eee H1 SUBSTRATE 0.27 1.45 MIN 1.72 0.60 NOM 1.82 0.63 6.25 6.25 1.27 5.08 5.08 0.32 1.50 DIMENSIONS Ø eee S Z X Y Z 0.37 1.55 0.15 0.10 0.15 MAX 1.92 0.66 TOTAL NUMBER OF LGA PADS: 25 DETAIL A Øb (25 PLACES) DETAIL B H2 MOLD CAP NOTES DETAIL B A b F 3 e SEE NOTES 4 3 2 1 PACKAGE BOTTOM VIEW 5 G DETAIL A E D C B A PIN 1 7 SEE NOTES 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 4 7 TRAY PIN 1 BEVEL ! PACKAGE IN TRAY LOADING ORIENTATION LTMXXXXXX µModule LGA 25 0613 REV Ø PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY 6. THE TOTAL NUMBER OF PADS: 25 5. PRIMARY DATUM -Z- IS SEATING PLANE LAND DESIGNATION PER JESD MO-222, SPP-010 3 2. ALL DIMENSIONS ARE IN MILLIMETERS NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 COMPONENT PIN “A1” (Reference LTC DWG # 05-08-1949 Rev Ø) LGA Package 25-Lead (6.25mm × 6.25mm × 1.82mm) LTM4632 Package Description Please refer to http://www.linear.com/product/LTM4632#packaging for the most recent package drawings. 4632fa 25 0.000 2.540 1.270 0.3175 0.3175 1.270 2.540 PACKAGE TOP VIEW SUGGESTED PCB LAYOUT TOP VIEW 2.540 4 1.270 PIN “A1” CORNER E 1.270 aaa Z 0.3175 0.000 0.3175 D X 0.630 ±0.025 Y aaa Z // bbb Z SYMBOL A A1 A2 b b1 D E e F G H1 H2 aaa bbb ccc ddd eee For more information www.linear.com/LTM4632 0.27 1.45 MIN 2.22 0.50 1.72 0.60 0.60 NOM 2.42 0.60 1.82 0.75 0.63 6.25 6.25 1.27 5.08 5.08 0.32 1.50 DIMENSIONS ddd M Z X Y eee M Z H1 SUBSTRATE b1 A2 MAX 2.62 0.70 1.92 0.90 0.66 NOTES DETAIL B PACKAGE SIDE VIEW 0.37 1.55 0.15 0.10 0.20 0.30 0.15 TOTAL NUMBER OF BALLS: 25 DETAIL A Øb (25 PLACES) DETAIL B H2 MOLD CAP ccc Z A1 A Z (Reference LTC DWG # 05-08-1502 Rev Ø) Z 26 2.540 b F 3 e SEE NOTES 4 3 2 1 PACKAGE BOTTOM VIEW 5 G DETAIL A E D C B A PIN 1 7 SEE NOTES DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE BALL DESIGNATION PER JESD MS-028 AND JEP95 7 TRAY PIN 1 BEVEL ! PACKAGE IN TRAY LOADING ORIENTATION LTMXXXXXX µModule BGA 25 0515 REV Ø PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY 6. SOLDER BALL COMPOSITION IS 96.5% Sn/3.0% Ag/0.5% Cu 5. PRIMARY DATUM -Z- IS SEATING PLANE 4 3 2. ALL DIMENSIONS ARE IN MILLIMETERS NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 COMPONENT PIN “A1” BGA Package 25-Lead (6.25mm × 6.25mm × 2.42mm) LTM4632 Package Description Please refer to http://www.linear.com/product/LTM4632#packaging for the most recent package drawings. 4632fa LTM4632 Revision History REV DATE DESCRIPTION A 05/16 Added BGA package PAGE NUMBER 1, 2, 26 4632fa 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 representaFor more information www.linear.com/LTM4632 tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. 27 LTM4632 Package Photo Design Resources SUBJECT DESCRIPTION µModule Design and Manufacturing Resources Design: • Selector Guides • Demo Boards and Gerber Files • Free Simulation Tools µModule Regulator Products Search 1. Sort table of products by parameters and download the result as a spread sheet. Manufacturing: • Quick Start Guide • PCB Design, Assembly and Manufacturing Guidelines • Package and Board Level Reliability 2. Search using the Quick Power Search parametric table. TechClip Videos Quick videos detailing how to bench test electrical and thermal performance of µModule products. Digital Power System Management Linear Technology’s family of digital power supply management ICs are highly integrated solutions that offer essential functions, including power supply monitoring, supervision, margining and sequencing, and feature EEPROM for storing user configurations and fault logging. Related Parts PART NUMBER DESCRIPTION COMMENTS LTM4622 Ultrathin, Dual 2.5A or Single 5A Step-Down µModule 3.6V < VIN < 20V, 0.6V < VOUT < 5.5V, 6.25mm × 6.25mm × 1.82mm LGA Regulator Package, 6.25mm × 6.25mm × 2.42 BGA Package LTM4623 Ultrathin, Single 3A Step-Down µModule Regulator 4V ≤ VIN ≤ 20V, 0.6V ≤ VOUT ≤ 5.5V, 6.25mm × 6.25mm × 1.82mm LGA Package, 6.25mm × 6.25mm × 2.42 BGA Package LTM4644 Quad 4A Step-Down µModule Regulator 4V < VIN < 14V, 0.6V < VOUT < 5.5V, 9mm × 15mm × 5.01mm BGA Package LTM4630 µModule Regulator for Higher Power VDDQ Supply 4.5V < VIN < 15V, 0.6V <VOUT <1.8V, Single 36A or Dual 18A, 16mm × 16mm × 5.01mm BGA Package, 16mm × 16mm × 4.41mm LGA Package LTM4650 µModule Regulator for High Power FPGA/ASIC Core Supply 4.5V < VIN < 15V, 0.6V <VOUT <1.8V, Single 50A or Dual 25A, 16mm × 16mm × 5.01mm BGA Package LTM4639 Low Input Voltage, Single 20A Step-Down µModule Regulator 2.375V < VIN < 7V, 0.6V < VOUT < 5.5V, 15mm × 15mm × 4.92mm BGA Package LTM4675 µModule Regulator with PSM for High Power, High Accuracy FPGA/ASIC Core Supply DC/DC µModule with Digital Power System Management, 4.5V < VIN < 17V, 0.5V < VOUT < 5.5V with ±0.5% Accuracy, Single 18A or Dual 9A LTM4677 µModule Regulator with PSM for High Power, High Accuracy FPGA/ASIC Core Supply DC/DC µModule with Digital Power System Management, 4.5V < VIN < 16V, 0.5V < VOUT < 1.8V with ±0.5% Accuracy, Single 36A or Dual 18A LTC3717 Step-Down Controller for VTT for DDR Memory Termination 4V < VIN < 36V, IOUT = ±20A, Requires External Inductor and MOSFET LTC6902 Multiphase Oscillator for Multiphase Operation 2-, 3- or 4-Phase, 5kHz to 20MHz Frequency Range 4632fa 28 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LTM4632 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTM4632 LT 0516 REV A • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2016