DC1568A - LINEAR TECHNOLOGY

dc1568afa

DEMO MANUAL DC1568A

Description

LT3652EDD

2A Monolithic Multichemistry

Battery Charger for Solar Power

Demonstration circuit 1568A is a 2A monolithic multi-

chemistry battery charger for solar power applications

featuring the LT3652EDD. The LT3652 is a complete

mid-power Li-Ion battery charger that can operate over

a wide input voltage range. The charger employs a 3.3V

ﬂoat voltage feedback reference that allows the battery

ﬂoat voltage to be adjusted up to 14.4V. The LT3652 has

an input voltage regulation loop which reduces charge

current if the input falls below a programmed level, set

with a resistor divider. The circuit provides CC/CV charging

with a 2A maximum charge current that is programmed 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.

PARAMETER CONDITIONS VALUE

Input Voltage Range 11.5V to 32V

VOUT 8.14V to 8.26V

Output Float Voltage Constant Voltage Mode 8.2V

Output Current Limit ILIM VIN_REG Greater Than 2.7V 2A

performance summary

a sense resistor. A precondition feature trickle charges a

low voltage battery, and bad battery detection provides a

signal if the battery does not respond to preconditioning.

The LT3652EDD is available in a 12-lead (3mm × 3mm)

DFN surface mount package with an exposed pad.

Design ﬁles for this circuit board are available at

http://www.linear.com/demo

(TA = 25°C)

operating principles

LT3652 is a complete monolithic mid-power Li-Ion battery

charger, addressing high input voltage applications with

solutions that require a minimum of external components.

The IC uses a 1MHz constant frequency, average-current

mode step-down architecture.

The LT3652 maximizes efﬁciency during charging cycles

by using a bootstrapped supply to drive the internal power

switch. When the output voltage is programmed to 8.2V,

the circuit provides full charge over a wide 11.5V to 32V

input range. A precision threshold shutdown pin allows

the incorporation of UVLO functionality using a simple

resistor divider. The IC can also be put into a low current

shutdown mode, in which the input supply bias is reduced

to only 15µA.

The LT3652 charge current control allows maximum

power point tracking (MPPT) use with solar panels. The

overall maximum charge current is set using an exter-

nal inductor current sense resistor. An input voltage

regulation pin allows the charger to reduce the battery

charge current if necessary so the solar panel produces

the most power.

The LT3652 automatically enters a battery precondition

mode if the sensed battery voltage is very low. In this

mode, the charging current is reduced to 15% of the

programmed maximum, as set by the inductor sense

resistor, RSENSE. Once the battery voltage increases to

the precondition threshold, the IC automatically increases

dc1568afa

DEMO MANUAL DC1568A

Quick start proceDure

DC1568A is easy to set up to evaluate the performance

of the LT3652EDD.

Using short twisted-pair leads for any power connections,

with all loads and power supplies off, refer to Figure 1 for

the proper measurement and equipment setup.

Follow the procedure below:

1. Jumper and power supply settings:

JP1 = 1 JP4 = 1

JP2 = 1 PS1 = OFF

JP3 = C/10 PS2 = OFF

2. Turn on PS2 and slowly increase the voltage until VBAT

is 5.4V while monitoring the current into the BAT pin.

If the current is less than 5mA, turn on PS1. Increase

PS1 until VIN is 12V while monitoring the input current.

3. Verify that the battery charging current, IBAT, is between

250mA and 350mA. The CHRG LED should be on and

the FAULT LED should be off.

4. Increase PS2 until VBAT is 7.2V. Verify that the input

current, IIN, is between 1.3A and 1.7A, the battery cur-

rent, IBAT, is between 1.775A and 2.225A and that the

CHRG LED is on.

5. Increase PS2 until VBAT is 8.5V. Verify that the battery

charging current, IBAT, is less than 5mA and that the

CHRG LED is off.

6. Decrease PS2 until VBAT is 7.8V. Verify that the battery

current, IBAT, is between 1.775A and 2.225A and that

the CHRG LED is on.

7. Set JP1 to 0. Verify that the charging current, IBAT, is

less than 5mA and that the FAULT LED and the CHRG

LED are off.

8. Set JP1 to 1. Connect a jumper from the NTC pin to

ground. Verify that the charging current, IBAT, is less

than 5mA and that the FAULT LED and the CHRG LED

are on.

maximum charging current to the full programmed value.

DC1568A programs the output voltage to be 8.2V, and the

5.7V precondition threshold is internally set as a fraction

of the programmed output voltage.

The LT3652 can use a charge current based C/10 ter-

mination scheme, which ends a charge cycle when the

battery charge current falls to one-tenth the programmed

maximum charge current. The LT3652 also contains an

internal charge cycle control timer, for timer-based termina-

tion. When using the internal timer, the IC combines C/10

detection with a programmable time constraint, during

which the charging cycle can continue beyond the C/10

level to “top off” a battery. The charge cycle terminates

when a speciﬁc time elapses, typically three hours. When

the timer based scheme is used, the IC also supports bad

battery detection, which triggers a system fault if a battery

stays in precondition mode for more than one-eighth of

the total charge cycle time.

Once charging is terminated and the LT3652 is not actively

charging, the IC automatically enters a low current standby

mode where supply bias currents are reduced to < 100µA.

If the battery voltage drops 2.5% from the full charge ﬂoat

voltage, the LT3652 engages an automatic charge cycle

restart. The IC also automatically restarts a new charge

cycle after a bad battery fault once the failed battery is

removed and replaced with another battery.

The LT3652 includes provisions for a battery tempera-

ture monitoring circuit. This feature monitors battery

temperature during the charging cycle using a thermistor,

and suspends charging and signals a fault condition if the

battery temperature moves outside a safe charging range

of 0°C to 50°C.

The LT3652 contains two digital open collector outputs,

which provide charger status and signal fault conditions.

These binary coded pins signal battery charging, standby

or shutdown modes, battery temperature faults and bad

battery faults.

operating principles

dc1568afa

DEMO MANUAL DC1568A

Quick start proceDure

Figure 1. Proper Measurement Equipment Setup for the DC1568A

9. Remove the jumper from NTC to ground. Verify that

the charging current, IBAT, is between 1.775A and

2.225A, that the FAULT LED is off and the CHRG LED

is on.

10. Turn on LOAD1 and set to 1A. Verify that the voltage,

VSYSTEM, on the SYSTEM LOAD turret is approx-

imately equal to VIN.

11. Set JP2 to 0. Verify that the battery charging current

is less than 5mA and that the CHRG LED is off.

12. Increase PS1 until VIN is 14V. Verify that the charging

current is between 1.775A and 2.225A and that the

CHRG LED is on. Set JP2 to 1.

13. Set JP4 to 0. Setting JP4 to 0 turns off the charge

current when VIN is less than 17.7V. Verify that the

battery charging current is less than 5mA and that

the CHRG LED is off.

14. Increase PS1 until VIN is 17.7V. Verify that the charging

current is between 1.775A and 2.225A and that the

CHRG LED is on. Set JP4 to 1.

15. Turn off PS1, PS2 and LOAD1.

NOTE: All connections from equipment should be Kelvin-

connected directly to the board pins which they are con-

nected to on the diagram in Figure 1, and any input or

output leads should be twisted pair.

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DEMO MANUAL DC1568A

parts list

ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER

Required Circuit Components

1 2 C2, C3 CAP., X7R, 4.7µF, 50V, 10%, 1210 MURATA, GRM32ER71H475KA88L

2 1 C4 CAP., X7R, 1µF, 50V, 10%, 0805 MURATA, GRM21BR71H105KA12B

3 1 C6 CAP., X5R, 100µF, 10V, 20%, 1210 TAIYO YUDEN, LMK325BJ107MM-T

4 1 C7 CAP., X7R, 10µF, 10V, 10%, 0805 MURATA, GRM21BR71A106KE51L

5 1 C10 CAP., X5R, 0.68µF, 10V, 10%, 0402 MURATA, GRM155R61A684KE15D

6 2 D1, D2 SMD, SCHOTTKY BARRIER RECTIFIER CENTRAL SEMI, CMSH3-40MA

7 1 D5 SMD, SCHOTTKY DIODE, SOT-23F CENTRAL SEMI, CMPSH1-4

8 1 L1 POWER INDUCTOR, 10µH, 20%, 3.5A VISHAY, IHLP2525CZER100M11

9 1 R1 RES., CHIP, 1M, 1/16W, 1%, 0402 VISHAY, CRCW04021M00FKED

10 1 R4 RES., CHIP, 536k, 1/16W, 1%, 0402 VISHAY, CRCW0402536KFKED

11 2 R5, R6 RES., CHIP, 100k, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED

12 1 R7 RES., CHIP, 0.05Ω, 1/2W, 1%, 1206 SUSUMU, RL1632R-R050-F

13 1 R10 RES., CHIP, 619k, 1/16W, 0.1%, 0603 NIC, NTR06B6193DTRF

14 1 R11 RES., CHIP, 417k, 1/16W, 0.1%, 0603 NIC, NTR06B4173DTRF

15 1 R12 RES., CHIP, 0.1Ω, 1/2W, 1%, 1206 SUSUMU, RL1632R-R100-F

16 1 U1 MULTICHEMISTRY 2A BATTERY CHARGER FOR

SOLAR POWER

LINEAR TECHNOLOGY, LT3652EDD

Optional Demo Board Circuit Components

1 1 C1 CAP., SMT, 390µF, 50V, 20% SUNCON, 50CE390BS

2 0 C5 CAP, OPT, 0402 CUSTOMER SELECTABLE

3 2 C8, C9 CAP, CHIP, X7R, 0.022µF, ±10%, 16V, 0402 AVX, 0402YC223KAT2A

4 1 D3 LED, RED PANASONIC, LNJ208R8ARA

5 1 D4 LED, GREEN LITE-ON, LTST-C190KGKT

6 0 D6 SMD, SCHOTTKY BARRIER RECTIFIER CENTRAL SEMI, CMSH3-40MA

7 2 R2, R3 RES., CHIP, 5.1k,1/4W, 1%, 1206 VISHAY, CRCW12065K10FKEA

8 1 R8 RES., CHIP, 20 ,1/16W, 5%, 0402 VISHAY, CRCW040220R0JNED

9 1 R9 RES., CHIP, 0 ,1/16W, 5%, 0402 VISHAY, CRCW04020000Z0ED

Hardware, for Demo Board Only

1 7 E1-E7 TESTPOINT, TURRET, 0.095" MILL-MAX, 2501-2-00-80-00-00-07-0

2 0 J1 HEADER, 3 PINS HIROSE ELECTRIC, DF3A-3P-2DSA

3 4 JP1-JP4 2MM SINGLE ROW HEADER, 3 PIN SAMTEC, TMM-103-02-L-S

4 4 JP1-JP4 SHUNT SAMTEC, 2SN-BK-G

5 4 STAND-OFF, NYLON, 0.625" TALL (SNAP ON) KEYSTONE, 8834 (SNAP ON)

dc1568afa

DEMO MANUAL DC1568A

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.

schematic Diagram

D D

C C

B B

A A

VIN

11.5V - 32V

TIMER

C/10

Unless noted:

Resistors: Ohms

0402

1/16W

Capacitors:

0402

10%

10V

8.2V

JP2

UVLO

1JP1

RUN

SHDN

OPT

0.1%

DC1568A

Monday, March 18, 2013

J.Drew 4/16/09

J.Drew 1/19/09

Multi-Chemistry 2A Battery Charger for Solar Power

LT3652EDD

SIZE

SCALE:

CAGE CODE DWG NO REV

SHEET OF

FILENAME:

TITLE

CONTRACT NO.

APPROVALS DATE

DRAWN

CHECKED

APPROVED

ENGINEER

DESIGNER

TECHNOLOGY

1630 McCarthy Blvd.

Milpitas, CA 95035

Phone: (408)432-1900

Fax: (408)434-0507

THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND

SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.

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.

CUSTOMER NOTICE

GND

10uF

10V

0805

10%

4.7uF

50V

1210

100K

CMPSH1-4

1 3

1uF

50V

0805

FAULT

RED

JP1

TP2

GND

R10

619K

0603

4.7uF

50V

1210

GND R2

5.1K

1206

JP4

R11

417K

0603

SYSTEM LOAD

R12

0.1

1206

1/2W

CMSH3-40MA

2 1

JP3

CMSH3-40MA

2 1

DF3-3P-2DSA

OPT

BAT

GND

NTC

5.1K

1206

LT3652EDD

VIN_REG

SHDN

BOOST

FAULT

VFB

CHRG

BAT

NTC

VIN

TIMER

SENSE

GND

L1 10uH

IHLP-2525CZ-11

1 2

390uF

50V

20%

NTC

536K

1.0Meg

5% C8

0.022uF

16V

0.05

1206

1/4W

OPT

100K

BAT

100uF

10V

1210

20%

CHRG

GRN

0.022uF

16V

CMSH3-40MA

2 1

JP2

TP1

C10

0.68uF

dc1568afa

DEMO MANUAL DC1568A

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

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

 LINEAR TECHNOLOGY CORPORATION 2011

LT 0313 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 direc-

tive 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.

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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:

Linear Technology

1630 McCarthy Blvd.

Milpitas, CA 95035