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All capacitors at input of LMS3655/35 
should be rated to 50VDC.

V

OUT

: 3.3V/5V

I

OUT

: 5.5A/3.5A

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Schematics

3

SNVU542 – July 2017

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LMS36x5x-Q1 EVM User's Guide

2

Schematics

Figure 2. Fixed - Output Voltage Option Schematic

The fixed voltage option has an internal resistor divider, and the FB pin connects directly to the output capacitance.

NOTE:

Cvcc and Cbias must connect directly to AGND, pin 20.

Summary of Contents for LMS3635MQEVM

Page 1: ...ormance allows for the elimination of a boost stage in many designs for start and stop applications An open drain RESET output with filtering and Power Good delay provides a true indication of system status This feature negates the requirement for additional supervisory circuitry saving cost and board space Seamless transition between PWM and PFM operation along with a low quiescent current ensure...

Page 2: ...ecifications for the LMS3635xQEVM and LMS3655xQEVM board Table 2 Technical Specification BOARD SIZE 4000 3000 mil 101 mm 76 mm 76 cm2 BOARD LAYER 4 Layer FR4 PCB Top Layer1 and Bottom Layer2 Mid Layer2 and Mid Layer3 2 8 mil 2 oz Cu 1 4 mil 1 oz Cu SOLUTION SIZE 700 mil 1700 mil 17 78 mm 43 18 mm 7 68 cm2 POWER INPUT VIN1 and GND1 IN IN Power Supply Input Power Input for EMI Test typical 13 5 V ra...

Page 3: ...bmit Documentation Feedback Copyright 2017 Texas Instruments Incorporated LMS36x5x Q1 EVM User s Guide 2 Schematics Figure 2 Fixed Output Voltage Option Schematic The fixed voltage option has an internal resistor divider and the FB pin connects directly to the output capacitance NOTE Cvcc and Cbias must connect directly to AGND pin 20 ...

Page 4: ... option uses an external resistor divider to define output voltage The CFF capacitor can be adjusted to make the feedback loop response faster for load transients By lowering the total resistance of the feedback divider the noise immunity can be increased NOTE To minimize noise coupling into the feedback pin the maximum resistance recommended for the feedback resistor RFBT is 50 kΩ The feedback re...

Page 5: ...8 shows the PCB Layout for each Cu Layer Top Layer 1 and Bottom Layer 4 are constructed using large filled Cu areas connected to GND This is done to improve thermal performance as well as improve overall EMI performance Mid Layer 2 is constructed using a large GND plane The purpose is to minimize loop inductance by placing metal directly under the Top Layer 1 traces which minimizes the cross secti...

Page 6: ... com 6 SNVU542 July 2017 Submit Documentation Feedback Copyright 2017 Texas Instruments Incorporated LMS36x5x Q1 EVM User s Guide Figure 5 PCB Layout Top Layer 1 Top View Figure 6 PCB Layout Mid Layer 2 GND Plane Top View ...

Page 7: ...42 July 2017 Submit Documentation Feedback Copyright 2017 Texas Instruments Incorporated LMS36x5x Q1 EVM User s Guide Figure 7 PCB Layer Mid Layer 3 Top View Figure 8 PCB Layer Bottom Layer 4 Flipped View as Seen From Bottom of Board ...

Page 8: ...yout www ti com 8 SNVU542 July 2017 Submit Documentation Feedback Copyright 2017 Texas Instruments Incorporated LMS36x5x Q1 EVM User s Guide Figure 9 PCB Layer Composite Top Figure 10 PCB Layer Composite Bottom ...

Page 9: ...tional 470 µF 50 V bulk capacitor to posts VIN1 and GND1 Always use sufficient power wires and separate measurement sense wires NOTE These sense lines are not designed to carry power 3 To accurately sense input and output voltage use the test points VINS VOUTS and GNDS Alternatively sense wires can be soldered directly over input capacitors Cin1 Cin2 Cin3 or Cin4 and the output capacitors Co1 Co2 ...

Page 10: ...d for minimal ground loop Ground loops can introduce ringing in observed waveforms which is an artifact not present on the PCB Alternatively use a differential probe over the output capacitors Do not use wires as a differential probe and always probe directly with shortest possible pins Make sure the IC is enabled by having jumper J2 set to EN VIN and check test point EN is driven high and not dro...

Page 11: ...nnects EN to VIN 5 5 VINS VOUTS and GNDS Probe VINS and VOUTS are sense points for input and output voltage NOTE Do not use for power supply or load These probe points are intended for use as kelvin sense points for static measurements including efficiency line regulation and load regulation For dynamic measurements please measure directly over the input capacitors Cin1 Cin2 Cin3 and Cin4 and dire...

Page 12: ...CERM 4 7 µF 16 V 10 X7R AEC Q200 Grade 1 0805 GCM21BR71C475KA73L C4 1 120 µF CAP AL 120 µF 16 V 20 0 024 ohm SMD APXE160ARA121MH70G C5 1 33 µF CAP Aluminum Polymer 33 µF 50 V 20 0 04 ohm AEC Q200 Grade 1 D6 3xL7 7mm SMD HHXA500ARA330MF80G C6 C9 2 0 1 µF CAP CERM 0 1 µF 50 V 10 X7R AEC Q200 Grade 1 0603 06035C104KAT2A C7 C8 C10 C11 4 4 7 µF CAP CERM 4 7 µF 50 V 20 X7R AEC Q200 Grade 1 1210 CGA6P3X7...

Page 13: ...63 W 0402 CRCW040212K4FKED R3 1 49 9 k RES 49 9 k 1 0 063 W 0402 CRCW040249K9FKED C16 C17 2 10 µF CAP CERM 10 µF 25 V 20 X7R 1210 C3225X7R1E106M250AC C19 1 22 pF CAP CERM 22 pF 50 V 5 C0G NP0 AEC Q200 Grade 1 0402 CGA2B2NP01H220J050BA Variant 003 LMS3655NQEVM Fixed 3 3 V 5 5 A With Spread Spectrum U1 1 3 5 5 5 A Synchronous Buck Regulator for Automotive Applications RNL0022A LMS3655NQRNLRQ1 R4 0 D...

Page 14: ...Output Current A Efficiency 0 1 2 3 4 5 6 50 55 60 65 70 75 80 85 90 95 100 LMS3 6 0 VIN 8 0 VIN 12 0 VIN 13 5 VIN 24 0 VIN 36 0 VIN Efficiency and Line and Load Regulation www ti com 14 SNVU542 July 2017 Submit Documentation Feedback Copyright 2017 Texas Instruments Incorporated LMS36x5x Q1 EVM User s Guide 7 Efficiency and Line and Load Regulation The LMS3655MQEVM variant is used for all measure...

Page 15: ...Regulation VOUT 5 V IOUT 200 mA to 3 5 A AUTO TR TF 1 µs Figure 17 LMS3655MQEVM Load Transients NOTE The output capacitance for all four variants is designed for stable operation across all load transients and optimized performance with a maximum load transient of 0 to 3 5 A For applications which require superior load transient performance beyond this range TI recommends increasing the output cap...

Page 16: ...ght 2017 Texas Instruments Incorporated LMS36x5x Q1 EVM User s Guide Figure 19 LMS3655MQEVM Low Frequency Conducted EMI Results for 5 Vout With Spread Spectrum Blue Average and Yellow Peak Figure 20 LMS3655MQEVM High Frequency Conducted EMI Results for 5 Vout With Spread Spectrum Blue Average and Yellow Peak ...

Page 17: ...y set forth above or credit User s account for such EVM TI s liability under this warranty shall be limited to EVMs that are returned during the warranty period to the address designated by TI and that are determined by TI not to conform to such warranty If TI elects to repair or replace such EVM TI shall have a reasonable time to repair such EVM or provide replacements Repaired EVMs shall be warr...

Page 18: ...the user guide with the maximum permissible gain and required antenna impedance for each antenna type indicated Antenna types not included in this list having a gain greater than the maximum gain indicated for that type are strictly prohibited for use with this device Concernant les EVMs avec antennes détachables Conformément à la réglementation d Industrie Canada le présent émetteur radio peut fo...

Page 19: ...ed loads Any loads applied outside of the specified output range may also result in unintended and or inaccurate operation and or possible permanent damage to the EVM and or interface electronics Please consult the EVM user guide prior to connecting any load to the EVM output If there is uncertainty as to the load specification please contact a TI field representative During normal operation even ...

Page 20: ...COST OF REMOVAL OR REINSTALLATION ANCILLARY COSTS TO THE PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES RETESTING OUTSIDE COMPUTER TIME LABOR COSTS LOSS OF GOODWILL LOSS OF PROFITS LOSS OF SAVINGS LOSS OF USE LOSS OF DATA OR BUSINESS INTERRUPTION NO CLAIM SUIT OR ACTION SHALL BE BROUGHT AGAINST TI MORE THAN TWELVE 12 MONTHS AFTER THE EVENT THAT GAVE RISE TO THE CAUSE OF ACTION HAS OCCURRED 8 2 Specif...

Page 21: ... TI Resource NO OTHER LICENSE EXPRESS OR IMPLIED BY ESTOPPEL OR OTHERWISE TO ANY OTHER TI INTELLECTUAL PROPERTY RIGHT AND NO LICENSE TO ANY TECHNOLOGY OR INTELLECTUAL PROPERTY RIGHT OF TI OR ANY THIRD PARTY IS GRANTED HEREIN including but not limited to any patent right copyright mask work right or other intellectual property right relating to any combination machine or process in which TI product...

Page 22: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Texas Instruments LMS3635MQEVM LMS3655AQEVM LMS3655NQEVM LMS3655MQEVM ...

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