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Setup

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6

SLVUAS6A – March 2017 – Revised January 2018

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Copyright © 2017–2018, Texas Instruments Incorporated

LP2951EVM

3

Setup

These sections describe the jumpers and connectors on the EVM as well as how to properly connect,
setup, and use the LP2951EVM.

3.1

Input/Output Connectors and Jumper Description

NOTE:

Connectors J1-J3 and J12-J14 are blank SMB connectors. These can be populated, or wires

can be soldered directly to them. The middle connection of the connector is the signal, while
the four edge connections are all ground.

3.1.1

J5 - Input

Input for power. Connect supply to this connector.

3.1.2

J6- Feedback

Determines the output voltage. Connected to V

TAP

through R

1

with standard setup.

3.1.3

J7 - ERROR

Error output connector. This active low output determines if the output voltage is within 6% of its expected
value.

3.1.4

J4/J8 - GND

Return path connectors.

3.1.5

J9 - Output

Regulated output voltage connectors.

3.1.6

J10 - Sense

Output voltage sensing connectors.

3.1.7

J11 - Shutdown

Device shutdown connectors. By shorting the middle pin of J11 to the pin labeled as N, the device
remains active. If the middle pin of J11 is shorted to the pin labeled Y, the device will shutdown. See

Table 2

for shutdown jumper position connection.

Table 2. Shutdown Jumper Position Versus Output

Jumper Position

Output

N

Enabled

Y

Disabled

Summary of Contents for LP2951EVM

Page 1: ...hematic 10 7 Bill of Materials 11 List of Figures 1 EVM With SON Package and SOIC Pads 2 2 Input Capacitors C1 C3 3 3 Output Capacitors C4 C7 3 4 Location for Bypass Capacitor C8 4 5 R1 and R2 Used to Set Fixed Voltage Mode on EVM 4 6 Resistors R3 R6 Used to Set Output Voltage in Adjustable Voltage Mode 5 7 LP2951 Adjustable Output Voltage Block Diagram 7 8 EVM With Adjustable Mode Resistors Popul...

Page 2: ...951EVM 2 1 LP2951 Device The LP2951EVM comes populated with LP2951 50 Q1 in the SON package However this EVM can be used to evaluate the SOIC package LP2951 device as well Figure 1 shows the EVM populated with the SON package and the pads for the SOIC package on the board Table 1 shows all LP2951 part numbers and packages that are compatible with the LP2951EVM Figure 1 EVM With SON Package and SOI...

Page 3: ...outed in series with a 1 Ω resistor R7 from the output to ground This series resistance helps stabilize the internal amplifier of the LP2951 device See the LP2951 or LP2951 N data sheet for the recommended series resistance when using a ceramic output capacitor C5 comes populated on the board and has a value of 2 2 µF C4 and C6 are pads that allow for additional output capacitors to be put on the ...

Page 4: ...s may especially be a problem when using high value external resistors to set the output voltage To fix this problem populate C8 with a 100 pF capacitor and increase the output capacitor to at least 3 3 µF See the LP2951 and LP2951 N data sheets for more information regarding the Cbypass Figure 4 Location for Bypass Capacitor C8 2 5 Fixed Output Voltage Resistors Resistors R1 and R2 are 0 Ω resist...

Page 5: ...so resistors R1 and R2 must first be removed Resistors R4 R6 form a voltage divider and can be populated with values based on the desired output voltage by following the equation on the EVM R3 must be populated with a 0 Ω resistor to short the Feedback pin of the device to the voltage divider of R4 R6 See Section 3 2 2 for additional information regarding setting an adjustable output voltage Figur...

Page 6: ...ut Input for power Connect supply to this connector 3 1 2 J6 Feedback Determines the output voltage Connected to VTAP through R1 with standard setup 3 1 3 J7 ERROR Error output connector This active low output determines if the output voltage is within 6 of its expected value 3 1 4 J4 J8 GND Return path connectors 3 1 5 J9 Output Regulated output voltage connectors 3 1 6 J10 Sense Output voltage s...

Page 7: ...ut of 5 V 3 2 2 Adjustable Output Voltage Mode To enable the adjustable voltage mode the resistors R1 and R2 must be removed Resistors R4 R6 must be populated with specific values based on the desired output voltage while R3 is populated with a 0 Ω resistor The complete equation for the output voltage is where VREF is the nominal 1 235 V reference voltage and IFB is the Feedback pin bias current n...

Page 8: ...put voltage as necessary for test purposes 4 Thermal Guidelines and Layout Recommendations Thermal management is a key component in the design of any power converter and is especially important when the power dissipation in the LDO is high Use Equation 2 to approximate the maximum power dissipation for the particular ambient temperature where Where T J is the junction temperature TA is the ambient...

Page 9: ...ww ti com Board Layout 9 SLVUAS6A March 2017 Revised January 2018 Submit Documentation Feedback Copyright 2017 2018 Texas Instruments Incorporated LP2951EVM 5 Board Layout Figure 9 LP2951EVM Board Layout ...

Page 10: ...CK 0 1 80 k 39 0 k R5 R6 47 F 2 2 F 2 2 F 2 2 F 1 0 R7 C6 C5 C4 C7 1 2 1 2 1 2 J9 1 2 J8 1 2 J10 SENSE 1 2 J11 3 INPUT SHUTDOWN 1 2 FEEDBACK J6 1 2 ERROR OUTPUT 2 3 4 5 1 2 3 4 5 1 J1 J2 J3 J12 SENSE J13 SHUTDOWN J14 INPUT SHUTDOWN OUTPUT SENSE VTAP ERROR FEEDBACK SHUTDOWN R3 Copyright 2017 Texas Instruments Incorporated EVM Schematic www ti com 10 SLVUAS6A March 2017 Revised January 2018 Submit D...

Page 11: ...o 125 degC 8 Pin SON DRG Green RoHS no Sb Br DRG0008A LP2951 50QDRGRQ1 Texas Instruments C1 0 1 µF CAP CERM 1 µF 50 V 10 X7R 1206 1206 C3216X7R1H105K TDK C3 0 1 µF CAP CERM 1 µF 35 V 10 X7R 0603 0603 C1608X7R1V105K0 80AC TDK C4 0 2 2 µF CAP CERM 2 2 µF 35 V 10 X5R 0603 0603 GRM188R6YA225K A12D MuRata C6 0 2 2 µF CAP CERM 2 2 µF 50 V 10 X7R 1206 1206 GRM31CR71H225K A88L MuRata C7 0 47 µF CAP AL 47 ...

Page 12: ...ck Copyright 2017 2018 Texas Instruments Incorporated Revision History Revision History NOTE Page numbers for previous revisions may differ from page numbers in the current version Changes from Original March 2017 to A Revision Page Changed C7 value from 4 7 µF to 47 µF in Bill of Materials table 11 ...

Page 13: ...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 14: ...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 15: ...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 16: ...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 17: ... 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...

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