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User's Guide

SNVA392A – June 2009 – Revised April 2013

AN-1955 LM5009A Evaluation Board

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Introduction

The LM5009AEVAL evaluation board provides the design engineer with a fully functional buck regulator,
employing the constant on-time (COT) operating principle. This evaluation board provides a 5V output
over an input range of 8V to 75V. The circuit delivers load currents to 150 mA, with current limit set at a
nominal 260 mA.

The board’s specification are:

Input Voltage: 8V to 75V

Output Voltage: 5V

Maximum load current: 150 mA

Minimum load current: 0A

Current Limit: 260 mA (nominal)

Measured Efficiency: 90.6% (V

IN

= 8V, I

OUT

= 100 mA)

Nominal Switching Frequency: 130 kHz

Size: 2.6 in. x 1.6 in.

Figure 1. Evaluation Board - Top Side

All trademarks are the property of their respective owners.

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SNVA392A – June 2009 – Revised April 2013

AN-1955 LM5009A Evaluation Board

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Copyright © 2009–2013, Texas Instruments Incorporated

Summary of Contents for AN-1955 LM5009A

Page 1: ...rents to 150 mA with current limit set at a nominal 260 mA The board s specification are Input Voltage 8V to 75V Output Voltage 5V Maximum load current 150 mA Minimum load current 0A Current Limit 260...

Page 2: ...maximum load current the wire size and length used to connect the load becomes important Ensure there is not a significant drop in the wires between this evaluation board and the load 4 Board Connect...

Page 3: ...Cff is calculated from 2 where tON max is the maximum on time at minimum VIN and R3 R4 is the parallel equivalent of the feedback resistors The ripple at VOUT ranges from 26 mVp p to 66 mVp p over th...

Page 4: ...Limit Off Time When current limit is detected the on time period is immediately terminated and the off time forced by the LM5009A must be greater than the maximum normal off time which occurs at maxi...

Page 5: ...tion Board Schematic As Supplied Table 1 Bill of Materials Item Description Mfg Part Number Package Value C1 Ceramic Capacitor TDK C3216X7R2A105M or Murata GRM31CR72A105KA01L 1206 1 F 100V C2 Ceramic...

Page 6: ...gure 6 Efficiency vs Load Current Figure 7 Efficiency vs Input Voltage Figure 8 Output Voltage Ripple 6 AN 1955 LM5009A Evaluation Board SNVA392A June 2009 Revised April 2013 Submit Documentation Feed...

Page 7: ...Frequency vs Input Voltage Figure 10 Current Limit vs Input Voltage Figure 11 Line Regulation 7 SNVA392A June 2009 Revised April 2013 AN 1955 LM5009A Evaluation Board Submit Documentation Feedback Co...

Page 8: ...it Performance www ti com Figure 12 Load Regulation 8 AN 1955 LM5009A Evaluation Board SNVA392A June 2009 Revised April 2013 Submit Documentation Feedback Copyright 2009 2013 Texas Instruments Incorpo...

Page 9: ...SW Pin Trace 3 VOUT Trace 4 Inductor Current Vin 12V Iout 0 mA Figure 14 Discontinuous Conduction Mode Trace 1 SW Pin Trace 3 VOUT Trace 4 Inductor Current Vin 12V Iout 0 mA Figure 15 Discontinuous Co...

Page 10: ...11 PC Board Layout Figure 16 Board Silkscreen Figure 17 Board Top Layer 10 AN 1955 LM5009A Evaluation Board SNVA392A June 2009 Revised April 2013 Submit Documentation Feedback Copyright 2009 2013 Texa...

Page 11: ...Board Layout Figure 18 Board Bottom Layer Viewed from Top 11 SNVA392A June 2009 Revised April 2013 AN 1955 LM5009A Evaluation Board Submit Documentation Feedback Copyright 2009 2013 Texas Instruments...

Page 12: ...sponsible for compliance with all legal regulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related inf...

Page 13: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Texas Instruments LM5009AEVAL NOPB...

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