DC1533A - LINEAR TECHNOLOGY

dc1533af

DEMO MANUAL DC1533A

DESCRIPTION

LTM8045

Inverting/SEPIC µModule Converter

with Up to 700mA Output

Demo circuit DC1533A features the LTM

8045, an inverting/

SEPIC Module converter delivering up to 700mA of output

current. DC1533A is configured as an inverting converter,

but can be easily changed to a SEPIC configuration for

non-inverting step-up or step-down functionality. The

user adjustable features of the LTM8045 such as output

voltage, switching frequency, soft-start period and under-

voltage lockout can be changed on DC1533A simply by L, LT, LTC, LTM, µModule, Linear Technology and the Linear logo are registered trademarks of

Linear Technology Corporation. All other trademarks are the property of their respective owners.

PERFORMANCE SUMMARY

BOARD PHOTO

modifying or installing the appropriate resistors or capaci-

tor. The LTM8045 data sheet must be read in conjunction

with this demo manual to properly use or modify demo

circuit DC1533A.

Design files for this circuit board are available at

http://www.linear.com/demo

(TA = 25°C)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Minimum Input Voltage, VIN 2.8 V

Maximum Input Voltage, VIN 18 V

Regulator Output Voltage, VOUT–R2 = 60.4k –4.83 –5.19 V

Maximum Output Current, IOUT–VIN = 5V

VIN = 12V

430

580

Efficiency VIN = 5V, IOUT– = 400mA 80 %

Switching Frequency R1 = 130k 700 kHz

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DEMO MANUAL DC1533A

QUICK START PROCEDURE

Figure 1. Proper Measurement Equipment Setup

Demo circuit DC1533A is an easy way to evaluate the

performance of the LTM8045. Refer to Figure 1 for the

proper measurement equipment setup and Figure 2 for

the maximum output current versus input voltage, then

follow the procedure below:

NOTE: Do not hot-plug the VIN terminal at high input volt-

ages. Hot-plugging a power supply through wire leads

to the demonstration circuit can cause the voltage on

the extremely low ESR ceramic input capacitor to ring to

twice its DC value. In order to protect the LTM8045, an

aluminum electrolytic capacitor with higher ESR is placed

at the input terminals. This may protect against some, but

not all, input transients due to a hot-plugged power supply.

See Application Note 88 for more details.

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 VIN or

VOUT and GND terminals. See Figure 3 for proper scope

probe technique.

1. Place JP1 in the ON position.

2. Connect the power supply (with power off), load, and

meters as shown in Figure 1.

3. After all connections are made, turn on the input power

and verify that the output voltage is –5V.

NOTE: If the output voltage is too low, temporarily discon-

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

4. Once the proper output voltage is established, adjust

the load within the operating range and observe the

output voltage regulation, ripple voltage, efficiency and

other parameters.

NOTE: See the section that follows for instructions to

convert DC1533A to a 5VOUT SEPIC with a positive VOUT.

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DEMO MANUAL DC1533A

QUICK START PROCEDURE

INPUT VOLTAGE (V)

300

600

550

650

350

400

500

450

DC1533A F02

OUTPUT CURRENT (mA)

28104 6 12 14 16 18

Figure 2. Maximum Output Current vs Input Voltage for VOUT = –5V

Figure 3. Proper Scope Probe Technique

DC1533A F03

GNDVIN OR VOUT

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DEMO MANUAL DC1533A

Instructions to Convert DC1533A to a 5VOUT SEPIC with a Positive VOUT

1. Start with DC1533A. Disconnect all supplies and loads.

2. Remove R2 and install R3 = 45.3k as shown in Figure 4. R3 MUST BE PRESENT BEFORE OPERATION OTHERWISE

THE LTM8045 MAY BE DAMAGED.

Figure 4

3. Make three cuts on the top copper to separate the terminal labeled GND from the ground plane, as shown in

Figure 5. The terminal labeled GND is now VOUT+.

Figure 5

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DEMO MANUAL DC1533A

4. Solder the exposed copper together with braid to connect the terminal labeled VOUT– to the ground plane, as shown

in Figure 6. The terminal labeled VOUT– is now GND.

5. Change C2 to 100µF 6.3V 1206 or 1210. Change R1 to 115k to optimize the switching frequency.

Figure 6

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DEMO MANUAL DC1533A

PARTS LIST

ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER

Required Circuit Components

1 1 C1 CAP., X7R, 4.7µF, 25V, 10%, 1206 NIC, NMC1206X7R475K25TRPLPF

2 1 C2 CAP., X5R, 22µF, 16V, 10%, 1206 AVX, 1206YD226KAT2A

3 1 C3 CAP., X7R, 10nF, 16V, 10%, 0603 AVX, 0603YC103KAT2A

4 1 R1 RES., CHIP, 130k, 1% ,0603 VIAHSY, CRCW0603130KFKEA

5 1 R2 RES., CHIP, 60.4k, 1% , 0603 VISHAY, CRCW060360K4FKED

6 1 U1 I.C., LTM8045EY#PBF, BGA LINEAR TECH., LTM8045EY#PBF

Optional Demo Circuit Components

1 0 CIN1 CAP., SMT, 47µF, 50V SUNCON, 50CE47BS

2 0 C4 CAP., X7R, 47µF, 16V, 20%, 1210

3 0 C5 CAP., X7R, 4.7µF, 25V, 10%, 1206

4 0 L1, L2 IND., 1.0µH, 20%,1812 MURATA, LQH43CN1R0M03

5 0 R3 RES., 0603

6 0 R4 RES., CHIP, 0, 0603 VISHAY, CRCW06030000Z0EA

7 0 R5, R6 RES., CHIP, 0603

Hardware

1 6 E1-E6 TESTPOINT, TURRET, .095" MILL-MAX, 2501-2-00-80-00-00-07-0

2 1 JP1 2MM SINGLE ROW HEADER, 3 PIN SAMTEC, TMM-103-02-L-S

3 1 XJP1 SHUNT, .079" CENTER SAMTEC, 2SN-BK-G

4 4 (STAND-OFF) STAND-OFF, NYLON 0.375" TALL KEYSTONE, 8832(SNAP ON)

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DEMO MANUAL DC1533A

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 representa-

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

SCHEMATIC DIAGRAM

0 Ohm

60.4k

SYNC

S EE F IGURE 2 FO R

JP1 12

VOUT-

LTM8045EY

VIN H5

VIN H4

VIN G5

VIN G4

SYNC

RUN

GND

GND H2

GND

VOUT+ B1

VOUT+ A2

VOUT+ A1

GND

GND H3

VOUT+ B2

FB A3

VOUT- A4

VOUT- A5

VOUT- B4

VOUT- B5

GND

CIN1

47uF

50V

1.0uH C4

47uF

16V

1210

LQH43CN1R0M03

10nF

0603

6.3mm DIA

RUN

CONTROL

130k

THE MAXI MUM O UT PUT CURRENT

OPT

VOUT-

V ERSUS VIN.

E5 -5V

700kHz

VIN

LQH43CN1R0M03

VOUT-

E2 GND

OFF

22uF

16V

OPT

GND

NOTE: UNLESS OTHERWISE SPECIFIED

1. ALL RESISTORS ARE 0603 1%.

2. AL L CAPACI T O RS ARE 1 20 6.

1.0uH

4.7uF

25V

OPT

4.7uF

25V

OPT

2.8V - 18V

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DEMO MANUAL DC1533A

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

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

LT 0113 • PRINTED IN USA

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

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ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.

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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 applica-

tion engineer.

Mailing Address:

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1630 McCarthy Blvd.

Milpitas, CA 95035