Linear Technology LT8494 Demo Manual

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Page 1

Description

DC2242A F01

DEMO MANUAL DC2242A

LT8494

SEPIC/Boost DC/DC Converter with 2A,

70V Switch, and 7µA Quiescent Current

Demonstration circuit 2242A is a monolithic SEPIC con-

verter featuring LT

8494. The demo board is designed for

5V output from a 3V to 60V input at 450kHz switching frequency. The max output current is 1A when the input voltage is above 12V, and is reduced with lower input volt age. The quiescent current of LT8494 operating. Dual supply pins (V

is less than 7μA when

and BIAS) allow the part

to automatically operate from the most efficient supply.

Low ripple Burst Mode

operation increases the efficiency at the light load while keeping the output ripple below 10mV. Figure 1 shows the demo board efficiency at 12V input voltage. Figure 2 shows the maximum load current with different input voltages of the demo board.

EFFICIENCY (%)

The LT8494 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo manual for DC2242A. The LT8494 is assembled in 20-lead QFN and 20-lead plastic TSSOP packages. Proper board layout is essential for maximum thermal and electrical performance. See the data sheet sections for details.

Design files for this circuit board are available at

http://www.

L, LT , LT C , LT M, Linear Technology, the Linear logo and Burst Mode are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

linear.com/demo/DC2242A

2.5

2.0

1.5

1.0

0.4

LOAD CURRENT (A)

VIN = 12V V

OUT

= 450kHz

Figure 1. LT8494 Efficiency Figure 2. LT8494 Maximum Load Current

performance summary

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

OUT

EFE Efficiency at DC V

Input Supply Range 3 60 V

Output Voltage 4.86 5.04 5.24 V

Switching Frequency RT = 169kΩ 414 450 477 kHz

Max Output Current VIN = 12V 1 A

= 5V

10.20 0.6 0.8

Specifications are at TA = 25°C

= 12V, I

= 1A 80.3 %

OUT

0.5

MAXIMUM LOAD CURRENT (A)

INPUT VOLTAGE (V)

(Typical) vs Input Voltage

60100 30 5040

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DEMO MANUAL DC2242A

Quick start proceDure

DC2242A is easy to set up to evaluate the performance of the LT8494. Refer to Figure 3 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 V or V scope technique.

1. With power off, connect the input power supply to V

and GND terminals. See Figure 4 for the proper

OUT

and GND. Make sure that the input voltage does not exceed 60V.

2. With power off, connect loads from V

3. Turn on the power at the input.

4. Check for the proper output voltages (V

NOTE: If there is no output, temporarily disconnect the

load to make sure that the load is not set too high or is shorted.

5. Once the proper output voltage is established, adjust the load within the operating ranges and observe the output voltage regulation, ripple voltage, efficiency and other parameters.

to GND.

OUT

= 5V).

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Quick start proceDure

DEMO MANUAL DC2242A

Figure 3. Proper Measurement Equipment Setup

OUT

Figure 4. Measuring Input or Output Ripple

GND

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DEMO MANUAL DC2242A

parts List

ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER

Required Circuit Components

1 2 C2, C8 CAP., X7R, 2.2µF, 100V, 10%, 1210 MURATA, GRM32ER72A225KA35L

2 2 C3, C4 CAP., X7R, 47µF, 10V, 10%, 1210 MURATA, GRM32ER71A476KE15L

3 2 C5, C7 CAP., X7R, 1µF, 10V, 10%, 0603 MURATA, GRM188R71A105KA61D

4 1 C6 CAP., NP0, 4.7pF, 50V, ±0.25pF, 0603 MURATA, GRM1885C1H4R7CA01D

5 1 D1 DIODE, SCHOTTKY 100V, 2A, SMA ON SEMI., MBRA2H100T3G

6 1 L1 INDUCTOR, 15µH VISHAY, IHCL4040DZER150M5A

7 2 R1, R10 RES., CHIP, 1M, 1/10W, 0603 VISHAY, CRCW06031M00FKEA

8 1 R2 RES., CHIP, 316K, 1/10W, 1%, 0603 VISHAY, CRCW0603316KFKEA

9 1 R4 RES., CHIP, 100k, 1/10W, 1%, 0603 VISHAY, CRCW0603100KFKEA

10 1 R6 RES., CHIP, 169k, 1/10W, 1%, 0603 VISHAY, CRCW0603169KFKEA

11 1 R9 RES., CHIP, 0, 1/10W, 0603 VISHAY, CRCW06030000Z0EA

12 1 U1 I.C., , LT8494, TSSOP-20-4.4mm LINEAR TECH., LT8494EFE#PBF

Additional Demo Board Circuit Components

1 1 C1 CAP., ALUM, 10µF, 63V, 20% SUN ELECTRONIC, 63CE10BS

2 0 C10 (OPT) CAP., OPTION, 0603 OPT

3 0 R11 (OPT) RES., OPTION, 0603 OPT

Hardware

: For Demo Board Only

1 6 E1-E6 TESTPOINT, TURRET, .094" PBF MILL-MAX, 2501-2-00-80-00-00-07-0

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DEMO MANUAL DC2242A

schematic Diagram

LT8494EFE

SEPIC CONVERTER WITH LOW IQ

IC NO. REV.

SIZE

SHEET OF

DEMO CIRCUIT 2242A

Tuesday, May 05, 2015

N/A

DATE:

VOUT

5V / 1A

MBRA2H100T3G

R11M1%

1uF

47uF

4.7pF

10V

0603

1210

C10

GND

OPT

www.linear.com

100K

316K

www.linear.com

Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

Fax: (408)434-0507

Milpitas, CA 95035

Phone: (408)432-1900

1630 McCarthy Blvd.

LTC Confidential-For Customer Use Only

TECHNOLOGY

SCHEMATIC

TITLE:

15uH

IHCL4040DZ-5A

1 3

1210

2.2uF

100V

LT8494EFE

BIAS

VIN

3V - 60V

SWEN

2.2uF

100V

10uF

63V

NC5NC

1210

63CE10BS

GND

R10

SS8RT

1uF

SWEN

GND

169K

R11

(450kHz)

OPT

CUSTOMER NOTICE

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;

THE MAX LOAD CURRENT IS REDUCED WHEN THE

INPUT VOLTAGE IS LESS THAN 12V. PLEASE SEE

DEMO MANUAL FOR DETAILS.

TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.

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.

NOTES: UNLESS OTHERWISE SPECIFIED

1. ALL RESISTORS ARE IN OHMS, 0603.

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.

ALL CAPACITORS ARE IN MICROFARADS, 0603.

D D

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.

C C

B B

A A

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DEMO MANUAL DC2242A

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

1630 McCarthy Blvd., Milpitas, CA 95035-7417

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

dc2242af

LT 0715 • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 2015