Linear Technology DC1229B User manual

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dc1229bf
DEMO MANUAL DC1229B
Description
LT3650EDD-4.2/LT3650EDD-4.1
2A Monolithic Li-Ion
Battery Chargers
DC1229B is a 2A monolithic Li-Ion battery charger featur-
ing the LT
®
3650EDD-4.2/LT3650EDD-4.1. The LT3650 is a
complete mid-power Li-Ionbattery charger that canoperate
over a wide input voltage range. The circuit provides CC/CV
charging with a maximum charge current externally pro-
grammable up to 2A. A precondition feature trickle charges
a low-voltage battery and bad battery detection provides 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.
perForMAnce sUMMArY
operAting principles
a signal if the battery doesn’t respond to preconditioning.
The LT3650EDD 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)
PARAMETER CONDITIONS VALUE
Input Voltage Range 7.5V to 32V
VOUT 3.7V to 4.24V
Output Float Voltage Constant Voltage Mode 4.2V/4.1V
Output Current Limit ILIM RRNG = 20kΩ 2A
LT3650 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. Internal reverse voltage
protection allows direct connection to the input supply
without a blocking diode for single-cell applications
(LT3650-4.2/LT3650-4.1).
NOTE: A blocking diode on the input supply connection
is recommended to prevent the input from ringing below
ground with a battery on the output.
The LT3650 incorporates a 2A switch that is driven by a
bootstrapped supply to maximize efficiency during charg-
ing cycles. Wide inputrange allows operation to full charge
from 5V ±5% (single cell) to 36V. A precision-threshold
shutdown pin allows 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 LT3650 incorporates several degrees of chargecurrent
control freedom. The overall maximum charge current is
set using an external inductor current sense resistor. A
maximum charge currentprogramming pin allowsdynamic
manipulation of the battery charge current. The LT3650
also incorporates a system input-supply current limit
control feature that servos the battery charge current to
accommodate overall system load requirements.
The LT3650 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 climbs above an internally set
threshold of 2.9V/cell, the IC automatically increases
maximum charging current to the full programmed value.

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DEMO MANUAL DC1229B
operAting principles
TheLT3650canuseacharge-currentbased‘C/10’termina-
tion scheme, which ends a charge cycle when the battery
charge current falls to 1/10th the programmed maximum
charge current. TheLT3650 also contains aninternal charge
cycle controltimer, for timer-basedtermination. 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 3 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 1/8th of the total charge cycle time.
Once charging is terminated and the LT3650 is not actively
charging, the IC automatically entersa 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 LT3650 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 LT3650 contains provisions for a battery temperature
monitoring circuit. This feature monitors battery tem-
perature 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 LT3650 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.
qUick stArt proceDUre
DC1229 is easy to set up to evaluate the performance of
the LT3650EDD-4.2/LT3650EDD-4.1.
Use a blocking diode on the input supply connection, and
short twisted pair leads for the 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 Setting:
JP1 = 1 PS1 = OFF
JP2 = 1 PS2 = OFF
JP3 = C/10
2. Turn on PS2 and slowly increase the voltage until VBAT
is 2.7V while monitoring the current into the BAT pin.
If the current is less than 5mA, turn on PS1. Increase
PS1 until VIN is 5V while monitoring the input current.
If the current is less than 5mA, increase PS1 until VIN
is 12V.
3. Verifythat the batterycharging current, IBAT, is between
200mA and 300mA. The CHRG LED should be on and
the FAULT LED should be off.
4. Increase PS2 until VBAT is 3.6V. Verify the input cur-
rent, IIN, is between 700mA and 850mA, the battery
current, IBAT, is between 1.875A and 2.225A and that
the CHRG LED is on.
5. Increase PS2 until VBAT is 4.25V. Verify the battery
charging current, IBAT, is less than 5mA and that the
CHRG LED is off.
6. Decrease PS2 until VBAT is 3.9V. Verify the battery
current, IBAT, is between 1.875A and 2.225A and that
the CHRG LED is on.
7. Decrease PS2 until VBAT is 3.6V. Connect a 10k resistor
from the RNG/SS pin to ground. Verify the charging
current, IBAT, is between 850mA and 1.0A. Verify the
voltage, VRNG, on the RNG/SS turret is between 450mV
and 550mV and the voltage VNTC on the NTC turret is
between 1.8V and 1.9V. Remove the 10k resistor from
the RNG/SS pin to ground.
8. Set JP1 to SHDN. Verify the charging current, IBAT, is
less than 5mA and that the FAULT LED and the CHRG
LED are off.

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DEMO MANUAL DC1229B
qUick stArt proceDUre
Figure 1. Proper Measurement Equipment Setup
9. Set JP1 to RUN. Connect a jumper from the NTC pin to
ground. Verify the charging current, IBAT, is less than
5mA and that the FAULT LED and the CHRG LED are on.
10. Remove the jumper from NTC to ground. Verify the
charging current, IBAT, is between 1.875A and 2.225A
and that the FAULT LED is off and the CHRG LED is on.
11. Turn on LOAD1 and set to 1A. Verify the voltage,
VSYSTEM, on the system load turret is approximately
equal to VIN.
12. Turn off PS1, PS2 and LOAD1.
Note: Put a blocking diode between the input supply and the VIN terminal.
Kelvin connect the voltage meters directly to the board terminals as shown
on the diagram. Use twisted pair input and output leads.

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DEMO MANUAL DC1229B
pArts list
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 Capacitor, X7R, 1µF, 50V, 10%, 0805 Murata, GRM21BR71H105KA12B
2 2 C3, C6 Capacitor, X7R, 4.7µF, 50V, 10%, 1210 Murata, GRM32R71H475KA091B
3 1 C4 Capacitor, X7R, 10µF, 10V, 10%, 0805 Murata, GRM21BR71A106KE19B
4 2 C5, C8 Capacitor, Chip, X5R, 0.1µF, ±10%, 10V, 0402 AVX, 0402ZD104KAT2A
5 1 C7 Capacitor, X5R, 0.68µF, 10V, 10%, 0402 Murata, GRM155R61A684KE15D
6 1 C9 Capacitor, X5R, 100µF, 6.3V, 20%, 1206 Murata, GRM31CR60J107ME19L
7 1 D1 SMD, Schottky Barrier Rectifier Central Semi, CMSH3-40MA
8 1 D2 SMD, Schottky Diode, SOT-23F Central Semi, CMPSH1-4
9 1 L1 Power Inductor 6.8µH 20% 4.5A Vishay, IHLP2525CZER6R8M011
10 1 R4 Resistor, Chip, 0.05Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206-01-R050-F
11 1 R5 Resistor, Chip, 100k, 1/16W, 1%, 0402 Vishay, CRCW0402100KFKED
12 1 R7 Resistor, Chip, 1M, 1/16W, 1%, 0402 Vishay, CRCW04021M00FKED
13 1 R8 Resistor, Chip, 0.1Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206-01-R100-F
14 1 U1 (Option A)
U1 (Option B)
2A Monolithic Li-Ion Battery Charger Linear Technology, LT3650EDD-4.2
Linear Technology, LT3650EDD-4.1
Optional Demo Circuit Components
1 1 C2 Capacitor, SMT, 22µF, 50V, 20% Sanyo, 50CE22BS
2 2 C10, C11 Capacitor, Chip, X7R, 0.022µF, ±10%, 16V, 0402 AVX, 0402YC223KAT2A
3 0 R6 (Opt) Resistor, Chip, 0402 User Defined
4 1 D3 LED, Red Panasonic, LNJ208R8ARA
5 1 D4 LED, Green Lite-On, LTST-C190KGKT
6 1 R1 Resistor, Chip, 0 ,1/16W, 0805 Vishay, CRCW08050000Z0EA
7 2 R2, R3 Resistor, Chip, 5.1K,1/4W, 1%, 1206 Vishay, CRCW12065K10FKEA
8 0 C12 (Opt) Capacitor, Chip, X7R, 0.01µF, ±10%, 50V, 0603 AVX, 06035C103KAT2A
Hardware
1 8 E1-E8 Testpoint, Turret, .095" Mill-Max, 2501-2-00-80-00-00-07-0
2 1 J1 Header, 3 Pins Hirose Electric, DF3A-3P-2DSA
3 3 JP1, JP2, JP3 2MM Single Row Header, 3 Pin Samtec, TMM-103-02-L-S
4 3 JP1, JP2, JP3 Shunt Samtec, 2SN-BK-G
5 4 Stand-Off, Nylon 0.375" Tall (Snap-On) Keystone, 8832 (Snap On)

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DEMO MANUAL DC1229B
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
5 5
4 4
3 3
2 2
1 1
D D C C B B A A
VIN
7.5V - 32V
TIMER
C/10
2A
Unless noted: Resistors: Ohms 0402 1% 1/16W Capacitors: 0402 10% 10V
VFLOAT *
(OPT)
X
VERSION TABLE
JP2
Assembly Version
UVLO
VFLOAT *
DC1229B - A DC1229B - B
0
4.2V
U1
0
LT3650EDD - 4.2
1JP1
1
*
1
LT3650EDD - 4.1 4.1V
0
0
RUN
1
SHDN
1
*
B
DC1229B - A/B
Wednesday, April 01, 2009
11
J.Drew 1/19/09
J.Drew 1/19/09
2A Monolithic Li-Ion Battery Charger
LT3650EDD - 4.2 / LT3650EDD - 4.1
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: [phone] Fax: [phone]
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
E8
GND
C4
10uF 16V
0805
10%
C6 4.7uF 50V 1210
R5
100K
D2
CMPSH1-4
1 3
2
C1
1uF
50V
0805
D3
FAULT
RED
JP1
1
2
3
E7
RNG / SS
R6
(OPT)
C12 0.01uF 0603 50V
E5
GND
C3 4.7uF 50V 1210
E3
GND R2
5.1K 1206
E1
SYSTEM LOAD
E2
R8
0.1 1206
1/2W
JP3
1
2
3
D1
CMSH3-40MA
2 1
J1
DF3-3P-2DSA
(OPT)
1 2 3
BAT GND NTC
R3
5.1K 1206
LT3650EDD
U1
2 3
11
5
7
4
9 8
1 6
12
10
13
CLP SHDN
BOOST
FAULT
RNG/SS
CHRG
BAT
NTC
VIN
TIMER
SW
SENSE
GND
C8 0.1uF
L1 6.8uH
IHLP-2525CZ-01
1 2
+
C2 22uF
50V
20%
12
E6
NTC
R7 1.0Meg
C10
0.022uF
16V
R4 0.05 1206 1/4W
R1 0 0805
E4
BAT
C9 100uF
6.3V
1206
20%
D4
CHRG
GRN
C11 0.022uF 16V
JP2
1
2
3
C5
0.1uF
C7 0.68uF

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DEMO MANUAL DC1229B
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2011
LT 0711 • 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
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 applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation

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