Linear Technology LT3015 Quick Start Manual

DESCRIPTION

DEMONSTRATION CIRCUIT

1728A QUICK START GUIDE

LT3015

1.5A, Low Noise, Negative Linear Regulator with Precision Current Limit

Demonstration circuit 1728A is an adjustable 1.5A negative linear regulator featuring the LT3015. This device supplies up to 1.5A of output current at a typical dropout voltage of 300mV. Operating quiescent current is typically 1.1mA and drops to < 1A in shutdown. Quiescent current is also well controlled in dropout. In addition to fast transient response, the LT3015 exhibits very low output noise,

Internal protection circuitry includes reverse output protection, precision current limit with foldback and thermal limit with hysteresis.

The LT3015 is available as an adjustable device with a –1.22V reference voltage. Packages include the 5-lead TO-220 and DD-Pak, a thermally enhanced 12-lead MSOP and the low profile 8-lead 0.75mm × 3mm × 3mm DFN.

making it ideal for noise-sensitive applications.

The LT3015 datasheet gives a complete description of the

A key feature of the LT3015 is the capability to supply a wide output voltage range. The DC1728A can be set to –1.22V, –2.5V, –5.0V, –12.0V, –15.0V, as well as a user

device, operation and application information. The datasheet should be read in conjunction with this quick start guide for working on or modifying the demo circuit 1728A.

select option. In addition, the DC1728A is capable of delivering up to –1.5A output current, and can be used as a high current negative linear regulator, post regulator for switching supply, variable voltage supply or low output voltage power supply.

PERFORMANCE SUMMARY

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

IN

V

OUT

V

OUT

V

OUT

V

OUT

V

OUT

Input Supply Range V

Output Voltage Shunt at 1, 2 for JP2 –1.183 –1.22 –1.257 V

Output Voltage Shunt at 3, 4 for JP2 –2.425 –2.5 –2.575 V

Output Voltage Shunt at 5, 6 for JP2 –4.85 –5.0 –5.15 V

Output Voltage Shunt at 7, 8 for JP2 –11.64 –12.0 –12.36 V

Output Voltage Shunt at 9, 10 for JP2 –14.55 –15.0 –15.45 V

(TA = 25°C)

= –1.22V, I

OUT

Design files for this circuit board are available at http://www.linear.com/demo

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

= –1mA –1.8 –30 V

OUT1

dc1728af

1

DEMONSTRATION CIRCUIT 1728A QUICK START GUIDE

QUICK START PROCEDURE

Demonstration circuit 1728A is easy to set up to evaluate the performance of the LT3015. Refer to Figure 1 for proper measurement equipment setup and follow the procedure below:

NOTE. When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the terminals of the input or output capacitors. See Figure 2 for proper scope probe technique.

1. Place JP1 on the ON position.

NOTE. Put JP1 = 1-2 for ON, JP1 = 1-4 for OFF, or JP1 = 1-3 for User Select.

2. Use JP2 to set the desired output voltage.

3. With power off, connect the input power supply to V and GND.

4. Turn on the power at the V

NOTE. Make sure that the V –30V.

5. Check for the proper output voltages.

NOTE. If there is no output, temporarily disconnect the load to make sure that the load is not set too high or is shorted.

6. Once the proper output voltages are established, adjust the loads within the operating range and observe the output voltage regulation, efficiency and other parameters.

NOTE. Make sure that the power dissipation is limited below the thermal limit.

.

IN

voltage does not exceed

IN

2

Figure 1. DC1728A Proper Equipment Setup

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QUICK START PROCEDURE

Thermal Image

An example thermal image (Figure 3) shows the temperature distribution on the board. The test is done in still air at room temperature with 1.96W power dissipation in the LT3015. This gives the IC case-to-ambient thermal resistance

= 23°C/W on the demo board.

θ

JA

DEMONSTRATION CIRCUIT

1728A QUICK START GUIDE

V

IN

Figure 2. Measuring Input or Output Ripple

GND

Figure 3. Temperature Rise at 1.96W Dissipation

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3

DEMONSTRATION CIRCUIT 1728A QUICK START GUIDE

PARTS LIST

ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER

Required Circuit Components

11C

21C

3 1 R1 RES., CHIP, 3.48k, 1/16W, 1% 0402 VISHAY, CRCW04023K48FKED

4 2 R2, RSD RES., CHIP, 0, 0402 VISHAY, CRCW04020000Z0ED

5 1 R3 RES., CHIP, 3.65k, 1/16W, 1% 0402 VISHAY, CRCW04023K65FKED

6 1 R4 RES., CHIP, 11.0k, 1/16W, 1% 0402 VISHAY, CRCW040211K0FKED

7 1 R5 RES., CHIP, 30.9k, 1/16W, 1% 0402 VISHAY, CRCW040230K9FKED

8 1 R6 RES., CHIP, 39.2k, 1/16W, 1% 0402 VISHAY, CRCW040239K2FKED

9 1 R9 RES., CHIP, 100k, 1/16W, 1% 0402 VISHAY, CRCW0402100KFKED

Additional Demo Board Circuit Components

1 1 C1 CAP., ALUM., 10µF 50V, CE-BSS SUNCON, 50CE10BSS

2 0 C2 CAP., 7343

3 0 R7, R8 RES., CHIP, 0402

Hardware-For Demo Board Only

1 5 E1-E5 TP, TURRET, 0.094" MILL-MAX, 2501-2-00-80-00-00-07-0

2 1 JP1 JMP, 4 PINS, 0.079" SAMTEC, ASP-157349-01

3 1 JP2

4 2 XJP1, XJP2 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G

IN

OUT

U1 I.C., LT3015EDD, DFN8DD LINEAR TECH., LT3015EDD

CAP., X7R, 10µF 50V, 10%, 1210 MURATA, GRM32ER71H106K

CAP., X7R, 10µF 25V, 10%, 1206 MURATA, GRM31CR71E106KA12L

JMP, 2 × 6, 0.079"

SAMTEC, TMM-106-02-L-D

4

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SCHEMATIC DIAGRAM

DEMONSTRATION CIRCUIT

1728A QUICK START GUIDE

04-20-11

1

2

3

EDWIN L.

REVISION HISTORY

DESCRIPTION DATEAPPROVEDECO REV

PRODUCTION

1

_

VOUT

E1E1

8

U1

LT3015EDD

U1

LT3015EDD

IN

9

1

-1.5A MAX

C2

COUT

7

OUT

IN

2

E3E3

7343

OPT+C2

7343

OPT

+

10uF

25V

10uF

25V

SELECT USER

-15.0V

-12.0V

-5.0V

-2.5V

-1.22V

GND

1206

10 8

4 2

6

3

JP2

HD2X6-079

ADJ

SHDN

9 7 5 6 3 1

GND GND

B

Milpitas, CA 95035

1630 McCarthy Blvd.

Milpitas, CA 95035

1630 McCarthy Blvd.

Milpitas, CA 95035

R7

OPTR7OPT

R6

39.2kR639.2k

R5

11 12

30.9kR530.9k

R4

11.0kR411.0k

R3

3.65kR33.65k

R20R2

0

R1

3.48kR13.48k

5 4

1630 McCarthy Blvd.

A

.VER.ON CI

111102 ,02 lirpA ,yadsendeW

1

www.linear.com

Phone: (408)432-1900

Fax: (408)434-0507

LTC Confidential-For Customer Use Only

Fax: (408)434-0507

LTC Confidential-For Customer Use Only

Fax: (408)434-0507

LTC Confidential-For Customer Use Only

TECHNOLOGY

KT

APPROVALS

PCB DES.

WITH PRECISION CURRENT LIMIT

1.5A, LOW NOISE, NEGATIVE REGULATOR

SCHEMATIC

TITLE:

EDWIN L.

APP ENG.

SHEET OF

LT3015EDD

DEMO CIRCUIT 1728A

N/A

SIZE

DATE:

SCALE = NONE

1

2

3

4

5

D D

VIN VOUT

E2E2

VIN

-1.9V TO -30V

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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

*

RSD0RSD

R8

CIN

C1

0

OPTR8OPT

10uF

+

E5E5

50V

GND

1210

JP1JP1

ON

2

13

SUNCON

50CE10BSS

OFF

4

USER

R9

SELECT

C C

100kR9100k

CUSTOMER NOTICE

4

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A

CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;

HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO

E4E4

SHDN

CAPACITOR C1 IS AN OPTIONAL PART. IT WAS INSERTED ON THE DC1728A TO

DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUE TO THE USE OF LONG INPUT

LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, THE CAPACITOR

IS NOT NEEDED. SEE APPLICATION NOTE AN88 FOR MORE DETAILS.

*

NOTES: UNLESS OTHERWISE SPECIFIED

B

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL

APPLICATION. COMPONENT SUBSTITUTION AND PRINTED

CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT

PERFORMANCE OR RELIABILITY. CONTACT LINEAR

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

ALL CAPACITORS ARE IN MICROFARADS.

2. INSTALL SHUNTS AS SHOWN.

1. ALL RESISTORS ARE IN OHMS, 0402.

A

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

5

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5

DEMONSTRATION CIRCUIT 1728A QUICK START GUIDE

DEMONSTRATION BOARD IMPORTANT NOTICE

Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:

This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.

If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.

The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or agency certified (FCC, UL, CE, etc.).

No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,

customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.

LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.

Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and

observe good laboratory practice standards. Common sense is encouraged.

This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC application engineer.

Mailing Address:

Linear Technology

1630 McCarthy Blvd.

Milpitas, CA 95035

Linear Technology Corporation

6

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com

dc1728af

LT 0611 • PRINTED IN USA

Mouser Electronics

Authorized Distributor

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