DC2297A-A - ANALOG DEVICES

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DEMO MANUAL DC2297A

DESCRIPTION

LT8570, LT8570-1

Boost/SEPIC/Inverting Regulator

Demonstration circuits 2297A-A and 2297A-B feature the

8570 and LT8570-1 in a boost configuration. These

demo circuits demonstrate small size and low component

count. Both converters are designed to convert a 5V to

10V source to 12V. Refer to Figures 3 and 4 for maximum

load current at different input voltage levels.

Both converters use only one feedback resistor to set the

output voltage.

The LT8570 can operate with inputs as high as 40V but

in these demo circuits, the input is limited by the voltage

rating of the input capacitors, and the magnitude of the

output voltage.

PERFORMANCE SUMMARY

The LT8570 and LT8570-1 include many other features

such as synchronization to external clock, user configurable

undervoltage lockout, soft-start, frequency foldback, and

other features that are easily configured as Boost, SEPIC

or Inverting Converters.

The data sheet gives a complete description of the device,

operation and application information. The data sheet must

be read in conjunction with this demo manual for DC2297A.

Design files for this circuit board are available at

http://www.linear.com/demo/DC2297A

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.

Specifications are at TA = 25°C

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

DC2297A-A

VIN Input Supply Range 5 10 V

VOUT Output Voltage VIN = 5V, ILOAD = 125mA 11.64 12 12.36 V

RIPPLE VIN = 5V, ILOAD = 125mA 25 mV

EFFICIENCY VIN = 5V, ILOAD = 125mA 86 %

SWITCHING FREQUENCY 1.5 MHz

DC2297A-B

VIN Input Supply Range 5 10 V

VOUT Output Voltage VIN = 5V, ILOAD = 60mA 11.64 12 12.36 V

RIPPLE VIN = 5V, ILOAD = 60mA 5 mV

EFFICIENCY VIN = 5V, ILOAD = 60mA 86 %

SWITCHING FREQUENCY 1.5 MHz

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DEMO MANUAL DC2297A

QUICK START PROCEDURE

Demo circuit 2297A is easy to set up to evaluate the per-

formance of the LT8570 and LT8570-1. 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 VIN or

VOUT and GND terminals. See Figure 2 for proper scope

probe technique.

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

and GND.

2. Turn on the power at the input.

NOTE: Make sure that the input voltage does not

exceed 10V.

3. Check for the proper output voltage.

NOTE: If there is no output, temporarily disconnect the

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

4. Once the proper output voltages are established, adjust

the load within the operating range and observe the

output voltage regulation, ripple voltage, efﬁciency and

other parameters.

Figure 1. Proper Measurement Equipment Setup

–

+–

–

LOAD

–

POWER

SUPPLY VIN VOUT

IOUT

IIN

GND

VIN

Figure 2. Measuring Input or Output Ripple

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DEMO MANUAL DC2297A

QUICK START PROCEDURE

INPUT (V)

LOAD (mA)

450

400

300

200

100

350

250

150

075 9

DC2297A F03

1064 83

Figure 3. DC2297A-A Max Load Current vs Input Voltage

INPUT (V)

LOAD (mA)

240

220

180

140

100

200

160

120

075 9

DC2297A F04

1064 83

Figure 4. DC2297A-B Max Load Current vs Input Voltage

INPUT (V)

EFFICIENCY (%)

50 8040 120

DC2297A F05

1406020 1000

Figure 5. DC2297A-A Efficiency at 5VIN

INPUT (V)

EFFICIENCY (%)

50 3010 50

DC2297A F06

6020 400

Figure 6. DC2297A-B Efficiency at 5VIN

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DEMO MANUAL DC2297A

PARTS LIST

ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER

DC2297A-A

Required Circuit Components for Boost Regulator

1 1 C1 CAP., CER., 4.7µF, X7R, 16V, 10%, 0805 MURATA, GRM21BR71C475KA73L

2 1 C2 CAP., CER., 0.1µF, X7R, 16V, 10%, 0402 MURATA, GRM155R71C104KA88D

3 1 C3 CAP., CER., 2.2nF, X7R, 16V, 10%, 0402 AVX, 0402YC222KAT2A

4 1 C4 CAP., CER., 47pF, C0G, 25V, 5%, 0402 AVX, 04023A470JAT2A

5 1 C6 CAP., CER., 4.7µF, X7R, 16V, 10%, 0805 MURATA, GRM21BR71C475KA73L

6 1 D1 DIODE, SCHOTTKY, 30V, 1A, DI123 DIODES INC., DFLS130-7

7 1 L1 IND., 33µH WÜRTH ELEKTRONIK, 744 042 330

8 1 R2 RES., 11.3k, 1/8W, 1%, 0805 VISHAY, CRCW080511K3FKEA

9 1 R3 RES., 10k, 1/8W, 1%, 0805 VISHAY, CRCW080510K0FKEA

10 1 R5 RES., 56.2k, 1/10W, 1%, 0603 VISHAY, CRCW060356K2FKEA

11 1 R6 RES., 6.04k, 1/10W, 1%, 0603 NIC, NRC06F6041TRF

12 1 R7 RES., 130k, 1/10W, 1%, 0603 VISHAY, CRCW0603130KFKEA

13 1 U1 I.C., LT8570EDD, 8DFN LINEAR TECH., LT8570EDD#PBF

Additional Demo Board Circuit Components

1 1 C5 CAP., CER., 0.1µF, X7R, 16V, 10%, 0603 TDK, C1608X7R1C104K

2 1 R4 RES., 100k, 1/8W, 1%, 0805 VISHAY, CRCW0805100KFKEA

Hardware: For Demo Board Only

1 6 E1–E6 TEST POINT, TURRET, 0.094" MTG HOLE MILL-MAX, 2501-2-00-80-00-00-07-0

DC2297A-B

Required Circuit Components for Boost Regulator

1 1 C1 CAP., CER., 4.7µF, X7R, 16V, 10%, 0805 MURATA, GRM21BR71C475KA73L

2 1 C2 CAP., CER., 0.1µF, X7R, 16V, 10%, 0402 MURATA, GRM155R71C104KA88D

3 1 C3 CAP., CER., 2.2nF, X7R, 16V, 10%, 0402 AVX, 0402YC222KAT2A

4 1 C4 CAP., CER., 47pF, C0G, 25V, 5%, 0402 AVX, 04023A470JAT2A

5 1 C6 CAP., CER., 2.2µF, X7R, 16V, 10%, 0805 MURATA, GRM21BR71C225KA12L

6 1 D1 DIODE, SCHOTTKY, 30V, 1A, DI123 DIODES INC., DFLS130-7

7 1 L1 IND., 68µH U ELEKTRONIK, 744 042 680

8 1 R2 RES., 11.3k, 1/8W, 1%, 0805 VISHAY, CRCW080511K3FKEA

9 1 R3 RES., 10k, 1/8W, 1%, 0805 VISHAY, CRCW080510K0FKEA

10 1 R5 RES., 56.2k, 1/10W, 1%, 0603 VISHAY, CRCW060356K2FKEA

11 1 R6 RES., 6.04k, 1/10W, 1%, 0603 NIC, NRC06F6041TRF

12 1 R7 RES., 130k, 1/10W, 1%, 0603 VISHAY, CRCW0603130KFKEA

13 1 U1 I.C., LT8570EDD-1, 8DFN LINEAR TECH., LT8570EDD-1#PBF

Additional Demo Board Circuit Components

1 1 C5 CAP., CER., 0.1µF, X7R, 16V, 10%, 0603 TDK, C1608X7R1C104K

2 1 R4 RES., 100k, 1/8W, 1%, 0805 VISHAY, CRCW0805100KFKEA

Hardware: For Demo Board Only

1 6 E–E6 TEST POINT, TURRET, 0.094" MTG HOLE MILL-MAX, 2501-2-00-80-00-00-07-0

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DEMO MANUAL DC2297A

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

C6*

16V

0805

0.1µF

16V

0603

VOUT*

L1*

DFLS130

VIN

5V TO 10V

VIN SW

3 4

6.19k

0603

10k

0805

11.3k

0805

130k

0603

56.2k

0603

100k

0805

SHDN SHDN

GND

E5 GND

SYNC

SYNC SYNC

RTSS

98 67

2.2nF

47pF

0.1µF

4.7µF

16V

0805

ASSEMBLY TYPE U1 C6 L1 VOUT

DC2297A-A LT8570EDD 4.7µF 33µF 12V/125mA

DC2297A-B LT8570-1EDD 2.2µF 66µH 12V/60mA

* VERSION TABLE

U1*

SHDN

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DEMO MANUAL DC2297A

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

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

 LINEAR TECHNOLOGY CORPORATION 2015

LT 0315 REV A • 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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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.).

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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-

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