LX1671/LX1672 CLQ (MLPQ PACKAGE) MULTIPLE OUTPUT LOADSHARETM PWM EVALUATION BOARD USERS GUIDE I N T E G R A T E D Copyright © 2002 Revision 0.2d, 8/8/2002 P R O D U C T S LX1671 EVALUATION BOARD USER GUIDE TABLE OF CONTENTS Overview................................................................................................................................................3 LX1671 PWM Topology.........................................................................................................................3 LX1671 Features ...................................................................................................................................3 Evaluation Board Features ....................................................................................................................3 LoadSHARE (Bi-Phase) Operation........................................................................................................3 Configuration .........................................................................................................................................4 Initial Setup ............................................................................................................................................5 Single Phase / Bi-Phase ........................................................................................................................6 Required Test Equipment ......................................................................................................................6 Optional Test Equipment .......................................................................................................................6 Evaluation Board Operation...................................................................................................................6 Load Regulation.....................................................................................................................................7 Line Regulation......................................................................................................................................7 Over Current Protection.........................................................................................................................7 UVLO .....................................................................................................................................................7 Oscilloscope Waveforms .......................................................................................................................7 Schematic ............................................................................................................................................10 Bill Of Materials....................................................................................................................................11 Silk Screen and Etch Layers................................................................................................................12 Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 2 LX1671 EVALUATION BOARD USER GUIDE OVERVIEW The LX1671 evaluation board is designed to allow the user to get a detailed understanding of the operation of the LX1671 or LX1672 and to allow evaluation of several configurations that demonstrate the full capabilities of the controller. All three Pulse Width Modulator (PWM) phases and the Linear Regulator (LDO) can be completely evaluated. The LX1672 is a two phase version of the LX1671 Due to the flexibility of the LX1671 evaluation board a number of components must be selected for the specific mode of operation desired and to establish several variable parameters. The evaluation board is delivered with all required factory-installed components in a fully functional configuration. The LX1671 evaluation board can be delivered in a number of standard configurations. User changes to the standard board can be made for different applications and custom versions may be supplied in some situations. When the MLPQ package is used the LX1671 and the LX1672 have the same pinout so the circuit board can be used for either part. • Each PWM controller can operate from a different input voltage when in single or BiPhase. • When in Bi-Phase the currents supplied by each phase can be unbalanced with the LoadSHARE™ topology. • 300 KHz PWM Switching frequency. • Hiccup current limiting in all PWM outputs. • Reference allows low output voltages down to 0.8 volts.· • No current sense resistors; RDS(ON) is used for current limit and hiccup mode. • Soft start on each PWM and Under Voltage Lockout on VCC and upper FET drivers· • Output voltage power-up sequencing by selecting soft-start capacitor value. • Reference input on Phase 2 for forced current sharing or DDR memory data bus termination. EVALUATION BOARD FEATURES· • The heat sinking on the LX1671/72 evaluation board allows up to 8A out for each PWM phase. Note: The controller is capable of 15A out on all PWM phases but component selection and thermal limits on the evaluation board will prevent operating at full current. • Linear Regulator with pass transistor, limited to five watts power dissipation. • Provisions are made for different input voltages of 3.3, 5 , and 12 volts to be used as input power for each of the three phases. Bootstrap diodes and capacitors can be installed depending on the input voltage selected. • Three terminal blocks are provided to allow connection of input 3.3, 5, and 12 volt power. • Four terminal blocks are provided for connecting loads to the outputs. • A connector with jumpers allows enabling each PWM and the linear regulator independently. This document is intended to be used in conjunction with the LX1671 data sheet and LX1671 Product Design Guide (or LX1672 if applicable). LX1671 PWM TOPOLOGY The LX1671 is a PWM controller offering a high level of integration. Three separate synchronous, voltage mode PWM controllers are integrated into a single package. Phases 1 and 2 can be used in a BiPhase mode with LoadSHARE™ or used as two separate single-phase controllers. Phase 3 is always used in single phase. The single-phase buck regulators are limited to approximately 15 Amps maximum output by the available gate drive; the ability to operate in Bi-Phase allows output currents of 30 Amps by paralleling the output capabilities of two controller phases. There is also a controller for a linear regulator that utilizes an external pass transistor with a maximum output of approximately 5A. LX1671 FEATURES • Three synchronous PWM controllers • One LDO controller • Two PWM controllers can be operated in BiPhase to double the current output capability.· • In Bi-Phase the two PWMs operate 180 degrees out of phase to reduce input and output ripple current. Copyright © 2002 Rev 0.2d, 8/8/2002 LOADSHARE (BI-PHASE) OPERATION For LoadSHARE operation it is necessary to use phases 1 and 2 because of the different configuration of the phase 2 error amplifier input. The phase 2 error amplifier does not internally connect to the reference like the other two phases but is brought out to the (RF2) pin to allow a filtered feedback from phase 1 to be brought into the error amplifier. Phase 1 determines the output voltage and forces phase 2 to follow. When using Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 3 LX1671 EVALUATION BOARD USER GUIDE LoadSHARE the input power drawn by phase 1 and 2 can be different to proportion the available power. Phase 3 and the LDO operate independently and their output voltages can be set as desired. Jumpers are installed on J1 to disable each regulator independently. CONFIGURATION The LX1671 evaluation board is available in several standard configurations or it can be customized for specific applications. Note: For the purpose of this document one of the standard configurations (LX1671 EVAL -010) has been chosen to describe the evaluation board features and operation, all wording relates to this specific version. The standard board is designed for the MLPQ package. The LX1672 in the MLPQ Vout Phase 1 & 2 Vout Phase 3 Vout LDO Vin Phase 1 Vin Phase 2 Vin Phase 3 Vin LDO Phase 3 Phase 1 & 2 VCCL package has the same pinout so that the same circuit board can be used with either part. This configuration has three output voltages with phases 1 and 2 operating in LoadSHARE; phase 3 and the LDO each have their own outputs. The LoadSHARE configuration used is the ESR method where the current sharing ratio is determined by the ESR of the output inductors. Since both inductors are the same part number the current sharing ratio is 50% for each phase. The Schematic (Fig 7) and Bill of Material (Fig 8) are for the -010 version which is configured as shown in Table 1 below. Each evaluation board will have a Schematic and Bill of Material documenting that specific configuration. 1.5 Volts 2.5 Volts 2.5 Volts 5 Volts 3.3 Volts 12 Volts 3.3 Volts Single Phase LoadSHARE (Bi-Phase) 5 Volts Phase 1 (VC1) Phase 2 (VC2) Phase 3 (VC3) +12 Volts +12 Volts Bootstrap Table 1 LX1671–010 Eval Board Configuration Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 4 LX1671 EVALUATION BOARD USER GUIDE INITIAL SETUP Before applying any input power to the circuit board several choices must be made and the proper components must be chosen to allow operation with the desired characteristics. Note: The factory configuration is fully functional and can be changed if desired. Prior to changing the factory configuration, the following criteria should be considered: • Single Phase or LoadSHARE operation for Phase 1 and 2. • Input voltages for each of the three PWM regulators. • Will bootstrap be required, based on input voltages. • Output voltages for all four outputs. • Output current limit for PWM outputs. • Power up sequencing for output voltages. Once the above are known the proper components and jumpers must be installed for the following: • Feedback and low pass filters for phase 1 and 2 PWM regulators if LoadSHARE operation is selected. • Output voltage for Phase 2 if single phase operation is used. • Output voltage for Phase 1 and 3 if different from preset values. • Output voltage for the LDO if different from preset value • Bootstrap configuration if required. • Current Limit for the PWM (if other than the preset value). • Soft start capacitors if different start up sequence is required. When LoadSHARE operation is used low pass filtering is required on the two feedback paths from the outputs of phase 1 and 2 to the phase 2 error amplifier inputs. Typical values are shown on the evaluation board schematic, Figure (7) CONFIGURATION OPTIONS· Bootstrap A bootstrap circuit will be required if the high side FET driver supply voltage (VCX) is not at least 5 volts greater than the PWM input voltage ( high side FET drain voltage). A typical configuration is to use +12 for the high side gate driver, VCX, with either 3.3 or 5 as the PWM input, this gives sufficient gate drive to enhance the Copyright © 2002 Rev 0.2d, 8/8/2002 upper FET. An alternative is to use the bootstrap configuration to add 5 volts to the PWM input voltage which will generally make a slight improvement in efficiency by keeping the VCX voltage as low as possible and does not require a +12 volt input. If 12 volts is selected as the PWM input then bootstrapping will be required. Each of the three PWM phases has provisions for a diode, capacitor, and several 0 ohm jumpers that allow bootstrapping each phase independently. See schematic Figure (7). Be sure that the zero ohm jumpers are configured to connect either +12 or the bootstrap voltage to the VCX pins and add the diode and capacitor for that phase. The bootstrap diodes and capacitors are CR1-C26,CR2-C2, and CR3,-C25. Rectifier/Filter Since the LDO gets its power from VC1 using a bootstrap configuration for phase 1 results in the error amplifier having a square wave as its supply voltage. This square wave can be rectified and filtered by adding a second diode and capacitor to obtain a filtered output. VCCL can also be powered by a bootstrap rectifier/filter configuration, options allow deriving VCCL from either phase 2 or phase 3. Additional diodes and capacitors are used to implement a rectifier/filter with a clean DC output as follows, CR4-C33 for VC1; CR5-C9 for VCCL derived from phase 3; and CR10-C9 for VCCL derived from phase 2. By optimizing drive voltages it is possible to achieve small improvements in efficiency. Input Voltage Jumpers There are three resistors shown in series with each high side FET for the PWMs. These are actually zero ohm jumpers that connect the desired input voltage 3.3, 5, or 12 volts to the high side FET drain. Only one of the three can be installed per phase with the others left open. Similarly the LDO has three choices that allow 3.3 volts, 5 volts, or the output of phase 3 to be used for the input. R6 and R56 The resistors shown as R6 and R56 on the schematic are actually jumper wires due to the high currents that can flow in these paths. These are only installed for specific configurations. Parallel Diodes There are 3 Schottky diodes shown in parallel with the lower FETs on the PWM output stage. These diodes CR7-8- 9 may not be installed but can be used to help prevent negative spikes on the lower FET drain and will give a slight improvement in efficiency. Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 5 LX1671 EVALUATION BOARD USER GUIDE • Install a jumper for R26 - Connects the reference to phase 2 error amplifier positive input RF2· • Remove R18 and C22 - Filtered feedback to FB2· • Change R21 to 4.02K • Phase 2 voltage feedback • Select R17 and R20 to give the desired output voltage for phase 2 LoadSHARE Methods There are four basic methods used for LoadSHARE that are described in the LX1671 Product Design Guide. Numerous components are related to the implementation of these various methods. LoadSHARE Filters The low pass filters used for LoadSHARE operation are made up of R18-C22 for the FB2 input and R23-C6 for the RF2 input. Typical values are 61.9K and 4700pf. Proportional LoadSHARE U2 and U3 are only used if proportional LoadSHARE is desired. Several other components around U2 and U3 are also used only with proportional LoadSHARE control. LDO Soft Start CR6-C27-R27 can be used to ramp the LDO output up slowly if desired. The primary reason for this is to prevent a possible UVLO condition if 5 volts is used for the LDO input. If 5 volts is used for the LDO input and a sudden current demand is placed on it by the LDO load it can result in a transient on the 5 volts that will trigger the UVLO. Frequency Compensation Three resistors R8-13-22 set the gain of the PWM error amplifiers, these are typically 200K ohm and three capacitors C23-31-32 can be placed in parallel with the feedback resistors to lower the error amplifier bandwidth. Bulk Capacitors There are a number of output bulk capacitors. Phase one output C10-11; phase 2 output C12-13; phase 3 output C19-26. These are chosen to provide the required output filtering at the output voltage. R17 + R20 R20 VOUT = 0.8 This equation is simplified and does not account for drop across the input resistors due to error amplifier input current. It is suggested that input resistors be kept between 1K ohm and 10K ohm to minimize error and noise coupling from surrounding circuits. REQUIRED TEST EQUIPMENT • Multiple channel Oscilloscope with ten to one probes having short ground leads • Digital Multimeter • Power source (3.3 volts) if required for PWM input (factory configuration requires +3.3) • Power source (5 volts) with sufficient current for loads (factory configuration requires +5) • Power Source (12 volts) if required for PWM input or VCX (factory configuration requires +12) Resistive loads for all outputs at the required power levels for each output OPTIONAL TEST EQUIPMENT • Oscilloscope current probe with amplifier • Electronic loads SINGLE PHASE / BI-PHASE • LoadSHARE operation of phases 1 and 2 requires several component selections that are factory installed (if ordered for Bi-Phase operation). If single-phase operation of phase 1 and 2 is desired than modifications must be made as follows.· • Remove R6 (jumper wire) - Connects phase 1 and 2 outputs together • Remove R23 and C6 - Feedback filter to RF2· • Remove C5 and replace with a jumper Phase 2 feedback integrator capacitor • Change R22 to 200K - Phase 2 error amplifier gain· Copyright © 2002 Rev 0.2d, 8/8/2002 EVALUATION BOARD OPERATION Once all components have been installed power can be applied to the input terminal blocks and initial operation checked with no load. It is recommended that the power supplies used on the input have adjustable current limits that can be set to a low value for initial turn on of a new board. Apply all input voltages with current limits set below 1A and enable each output independently to verify that all outputs are functional and have the correct output voltage. Input power sequencing is not critical. Once every output has been verified for proper operation at no-load, a resistive load can be connected to each output (up to the desired output level). It is recommended that each output be loaded individually the first time to insure normal operation Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 6 LX1671 EVALUATION BOARD USER GUIDE and that each FET be checked for safe operating temperature after a few moments of operation at full load. When all outputs have been checked at full output current with resistive loads there are a number of tests that can be performed to evaluate performance. For details of operation see the LX1671 Product Design Guide. EFFICIENCY Since efficiency is always of interest it should be measured. Variables such as input voltage and output current effect efficiency so any measurements should be made at or close to actual values. Efficiency (h) can be expressed as : POUT maintain safe FET currents and temperatures. The initial RSET value is 1K ohm resulting in a 25A current limit, this will result in safe average FET temperatures and currents. UVLO The VCC and VCX pins are monitored by a undervoltage lockout circuit that will disable the PWM if either voltage is below the preset limit. The input voltages to these pin can be lowered to verify operation. All phases will shutdown if any monitored voltage goes below the threshold. The LDO is not effected by the UVLO. DYNAMIC LOADS Measure the output voltage at a fixed load and vary the load current over the range of interest. Observe the change in output voltage as a function of load current. In many applications it is required that the output voltage remain within specified limits for a specified step change in load current. The primary component that influences this specification is the output capacitor. A step change in output current will result in an instantaneous drop in output voltage that is the product of the output capacitor ESR and the magnitude of the current step. A current step can be applied using either a dynamic load or an external FET switch with an appropriate drain resistor to give the desired current change. A function generator can be used to supply the FET gate drive. The rise time of the current step can be controlled by adding resistance in series with the FET gate to slow down the switching time. LINE REGULATION OSCILLOSCOPE WAVEFORMS η= PIN × 100 Note: There will be voltage drops across the input terminal blocks and zero ohm jumpers that will effect efficiency measurements. The input voltage is best measured directly across the half bridge to obtain accurate results. The output voltage can be measured at the output capacitor. LOAD REGULATION Measure the output voltage and vary the input voltage over the range of interest. Observe the change in output voltage as a function of input voltage. Note: The under voltage lockout internal to the LX1671 requires greater than 4.5 volts VCC to operate and the VCC max is 6 volts. If the required input voltage range includes voltages less than 4.5 or more than 6 volts then the high side FET drain must be connected to a separate power supply to isolate it from VCC. VOUT Inductor Current Upper FET Gate OVER CURRENT PROTECTION Lower FET Gate Each output has a current protection limit that can be set to the desired maximum current by a resistor RSET. Short circuit current limits can be verified either by gradually increasing the load current or by applying a shorting wire across the output. The drain of the lower FET should be monitored with an oscilloscope to insure that the over current limit is functioning properly, during the hiccup period the lower FET will be held on. With a short circuit condition the LX1671 will go into a hiccup mode where the soft start mode is repeatedly cycled to Copyright © 2002 Rev 0.2d, 8/8/2002 Figure 1 – Phase 1 FET Gates & Output Upper and lower gate waveforms along with inductor current and output voltage. Note that the duty cycle is 30% corresponding to a 5 volt input with a 1.5 volt output. Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 7 LX1671 EVALUATION BOARD USER GUIDE off and the drain voltage is slightly below ground. This is caused by the FET body diode conducting due to inductor current flow from ground up to the phase node. When the FET actually turns on the drop is reduced due to the low RDS(on) in parallel with the body diode Inductor Current Lower FET Drain Voltage VOUT Lower FET Gate Soft Start Figure 2 – Phase 2 FET Gates & Output Lower FET gate drive against its drain voltage and inductor current. Note that the inductor current ramps up when the lower FET is off (upper FET on) and then ramps down when the lower FET is on. The difference in width between the low gate drive and high drain voltage is the non-overlap period where both FETs are off. Phase 1 – Lower FET Drain Voltage Phase 1 – Inductor Current Phase 2 – Inductor Current Output Current Figure 4 – Soft Start and Hiccup Mode An external switch is periodically connecting a load resistor across the output terminals. The load resistor is low enough to result in current pulses that exceed the current limit threshold determined by the RSET resistor. During the soft start interval the output voltage ramps up to the correct value while the current limit circuit limits the peak value of the current pulses. At the end of the soft start interval the next load pulse triggers the hiccup sequence causing the output voltage to go to zero until the end of the hiccup interval when the soft start ramp begins again. This sequence will repeat indefinitely keeping average FET temperatures within acceptable limits. Phase 2 – Lower FET Drain Voltage Figure 3 – Phase 1 versus Phase 2 Bi-Phase Waveforms of the phase node voltage and inductor currents of phase 1 and 2 operating in Bi-Phase. The drain voltage waveforms show the 180 degree out-of-phase operation of the two PWM controllers. The difference in duty cycle is due to phase 1 having a 5 volt input and phase 2 having a 3.3 volt input. If both input voltages were the same the inductor currents would also be 180 degrees out of phase. Note the non-overlap period where both FETs are Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 8 LX1671 EVALUATION BOARD USER GUIDE Phase 1 & 2 VOUT VOUT Phase 3 VOUT LDO VOUT IOUT +5 PWM Input Inductor Current Figure 5 – Start-Up Sequence Figure 6 – Phase 2 Transient Response Start-up sequence of phase 1 and 2 in Bi-Phase versus phase 3 and the LDO when the +5 input is switched on. Output voltage and inductor current of phase 3 when a 3 amp current step is applied to the output. Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 9 Copyright © 2002 Rev 0.2d, 8/8/2002 5 NU R47 VOUT1 1 2 +5V RTN Vout4 2.5V out 1 2 2 1 1 2 - + +5V NU R54 4 3 4 - 3 + C29 NU R23 61.9K 20K R29 5 R24 Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Microsemi NU R48 U2 LMC7101 NU 1 R49 NU R17 NU R26 NU NU C30 DIS-1 R50 100 R51 NU 20K R28 Q9 12 11 10 9 8 7 6 5 4 3 2 1 DIS-1 DIS-2 DIS-3 PW GD LDDIS R22 2.00K NU LDDIS C31 NDS7002A FB2 4700pF .22uF 4700pF 61.9K R18 C5 C7 C27 NU R44 499 R27 NU +12V CR6 NU C22/R20 61.9K R21 FB2 R25 1.58K 3.40K C6/R55 4700pF + C17 180uF 4V 2 +5V +3.3V VOUT3 SUD45N05-20L Q3 R43 NU R45 ZOJ R46 NU + C21 470uF 16V +12V + C20 680uF 6.3V +5V NDS7002A Q8 U3 LMC7101 NU DIS-2 TB3 TB2 TB1 Vout1 +12 RTN +12 VIN +5 RTN +5 VIN C4 .1uF 2.00K R19 EO2 FB2 RF2 SS2 36 35 34 33 32 U1 LX1671-CLQ 1 3 5 7 9 11 14 JI C28 15 16 NU 2 4 6 8 10 12 17 18 NU SS3 FB3 EO3 N/C CS3 VS3 N/C N/C VCC VCCL PG3 LO3 +5V +12V R41 ZOJ C8 2.00K R12 PWGD CR5 C32 +3.3 RTN TB7 2.00K R9 2 1 R11 2.00K VOUT1 2.00K R15 4.25K R10 5817 CR9 .22uF C26 + 5817 C2 + C24 180uF 4V R37 ZOJ R36 NU R35 NU +5V NU + C15 180 4V L3 5.0uh + C19 100uF 16V NU 1N5817 CR1 +3.3V 2.21K R16 Q7 Si4842DY C25 1N5817 CR2 CR3 C34 100uF 16V Q6 Si4842DY NU +12V DIS-3 +5V +3.3 VIN R14 2.00K 20K R30 Q10 NDS7002A 200K NU 4.7uF 10.0 NU NU CR4/R40 C1 NU R2 ZOJ 1.0uF CR10 R8 R7 2.00K DIS-1 DIS-2 C9 R42 R52 NU R53 ZOJ C3 .33uF 20 21 22 23 24 25 26 27 28 29 30 31 +5V R13 200K C23 19 CS VS SS FB EO CS VS 2 1 1 2 1 1 1 13 RSVD AGND DGND LDDIS LDFB LDGD VC2 HO2 37 LO PG LO HO VC VC HO 2 1 1 3 1 1 3 38 .22 C33 R38 ZOJ R39 NU R1 ZOJ R3 NU Approved By Approved By Checked By Drawn By 180 4V 2 1 RTN REVISIONS DESCRIPTION Date: B Size Title 5817 CR8 5817 R34 ZOJ 270uF 2V + C12 R5 NU R4 NU + C13 +12V +5V +3.3V + C11 +12V +5V +3.3V DATE 2 1 LX1671 EVAL - 010 Model No.: - 1 Drawing No: Sheet TB5 1 ES2825 of RTN Vout1 X1 Rev RTN Vout2 1.5V out R6 Jumper 2 1 APPR 1.5V out TB4 05/08/02 SCHEMATIC, LX1671 MLP EVALUATION BOARD L2 5.0uh 180uF 4V + C14 R56 NU 270uF 2V + C10 R33 NU R31 ZOJ R32 NU + C36 + C35 L1 5.0uh 150uF 6V + C18 ORIGINAL ECN #298 RELEASE CR7 Vout3 2.5V out ED120/2DS TB6 Q5 Si4842DY Q4 Si4842DY VOUT3 + C16 +12V +5V +3.3V Q2 Si4842DY Q1 Si4842DY - X1 LTR LX1671 EVALUATION BOARD USER GUIDE SCHEMATIC Figure 7 – LX1671 EVAL –010 Schematic Page 10 LX1671 EVALUATION BOARD USER GUIDE BILL OF MATERIALS LX1671 EVAL -010 MISCELLANEOUS COMPONENTS Line Item Part Description Manufacturer & Part # Reference Designators MLPQ U1 Qty 1 2 Int. Ckt, Multi-Phase PWM FAB, PWB, Eval Board X1 MICROSEMI MICROSEMI 3 Diode, Schottky, 1A 20V MICROSEMI UPS5817 4 Inductor, Power, 5µH, 6.5A Trans, N-Channel, 30V, 6mΩ, 19A, 35nC Max Trans, N-Channel, 30V, 18mΩ, 50A Trans, N-Channel, 60V, 2Ω Terminal Block, 2Pin Header, 12Pin, 2x6 Dual Row COOPER CTX5-4A SMD CR1,CR7, CR8,CR9 L1-L3 VISHAY SI4842DY SO-8 Q1, Q2, Q4-Q7 6 TO-252 SOT-23 Q3 Q8, Q9, Q10 TB1-B7 J1 1 3 7 1 Case Reference Designators Qty 1206 0805 0805 0805 0805 D7.3x4.3 D7.3x4.3 D7.3x4.3 D7.3x4.3 10x10.5 10x10.5 1206 C8 C4, C26, C33 C2,C7,C7,C25,C26 C3 C5, C6, C22 C10-C13 C14-C17, C24,C36 C18,C35 C19,C34 C20 C21 C9 1 3 4 1 3 4 6 2 2 1 1 1 Case Reference Designators Qty 5 6 7 8 9 LX1671CLQ SGE2825X1 Case SUD45N05-20L VISHAY FAIRCHILD NDS7002A SGE2442-2 PWRMITE 1 1 4 3 CAPACITORS Line Item 1 2 3 4 5 6 7 8 9 10 11 12 Part Description 4.7µF, 16V, Ceramic 0.1µF, 25V, ±10% 0.22µF, 25V, ±10% 0.33µF, 25V, ±10% 4700pF, 25V, ±10% 270µF, 2V, Poly Elect 180µF, 4V, Poly Elect 150µF, 6V, Poly Elect 100µF, 16V, Poly Elect 680µF, 6.3V, ±20% Poly 470µF, 16V, ±20%, AL-EL 1µF, 16V, Ceramic Manufacturer & Part # Taiyo Yuden EMK316BJ475ML ROHM MCH182CN104KK ROHM MCH182CN224KK ROHM MCH182CN334KK ROHM MCH182CN472KK CDE ESRE271M02B CDE ESRE181M04B CDE ESRE151M06B NEC NRD107M16 FUJITSU FP-063RE681M-R PANASONIC EEU-FC1C471 Taiyo Yuden EMK316BJ105ML RESISTORS Line Item Part Description Manufacturer & Part # 1 0Ω Jumper ROHM SGE2372-5 2 0Ω Jumper ROHM Buss Wire 4 2K, 1%, 1/8W ROHM MCR10F2001 0805 5 6 7 8 9 10 11 200K, 1%, 1/8W 4.25K, 1%, 1/8W 2.21K, 1%, 1/8W 61.9K, 1%, 1/8W 3.402K, 1%, 1/8W 1.58K, 1%, 1/8W 20K, 1%, 1/8W ROHM ROHM ROHM ROHM ROHM ROHM ROHM MCR10F2003 MCR10F4251 MCR10F2211 MCR10F6192 MCR10F3401 MCR10F1581 MCR10F2002 0805 0805 0805 0805 0805 0805 0805 0805 #18GA R3 R31, R34, R37, R41,R43, R45, R50, R53 R6 R7, R9, R11, R12, R14, R15, R19, R22 R8, R13 R10 R16 R18, R21, R23 R24 R25 R28-R30 9 1 8 2 1 1 3 1 1 3 Figure 8 Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 11 LX1671 EVALUATION BOARD USER GUIDE PCB SILK SCREEN Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 12 LX1671 EVALUATION BOARD USER GUIDE Figure10 Component Side Layer 1 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. Power Ground Phase 1 VOUT Phase 2 VOUT Power Ground Phase 2 Phase Node Phase 3 Input Phase 3 VOUT Phase 3 Phase Node Power Ground Phase 2 Input Phase 1 Input LDO Input Phase 1 Phase Node Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 13 LX1671 EVALUATION BOARD USER GUIDE PCB LAYOUT / LAYERS Figure 11 – Ground Plane Layer 2 1. Phase 1 Phase Node 2. Phase 2 Phase Node 3. Analog Ground Figure 12 - +5V Plane Layer 3 Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 14 LX1671 EVALUATION BOARD USER GUIDE PCB LAYOUT / LAYERS 1. Phase 1 Input 2. Phase 2 Input 3. Phase 3 Input Figure 13 - +12V Plane Layer 4 1. Phase 3 Phase Node 2. Phase 3 VOUT Figure 14 - +3.3V Plane Layer 5 Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Page 15 LX1671 EVALUATION BOARD USER GUIDE PCB LAYOUT / LAYERS 1. Phase 2 VOUT 2. Phase 1 VOUT 3. LDO Input Figure 15 – Layer 6 (Solder Side View) Copyright © 2002 Rev 0.2d, 8/8/2002 Microsemi Page 16 Integrated Products 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, FAX: 714-893-2570 Signatu re Not Verified KD Digitally signed by KD DN: cn=KD, o=Microse mi, c=US Date: 2002.08.08 08:00:44 -07'00'