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DESCRIPTION
DEMO MANUAL DC1362A-A/-B
LT3651EUHE-4.2/-4.1
4A High Voltage Li-Ion
Battery Charger
Demonstration circuit 1362A-A/1362A-B is a 4A high voltage
®
Li-Ion battery charger featuring the LT
LT3651EUHE-4.1. The LT3651 is a complete, high power
Li-Ion battery charger that can operate over a wide input
voltage range. The charger is a constant-current, constantvoltage type with a maximum charge current of
be externally set. A precondition feature trickle charges a
low voltage battery and bad battery detection provides a
PERFORMANCE SUMMARY
Input Voltage Range 6.5V to 32V
VOUT 2.9V to 4.24V (–A)/2.7V to 4.14V (–B)
Output Float Voltage (Constant Voltage Mode) 4.2V (–A)/4.1V (–B)
Output Current Limit ILIM 4A
3651EUHE-4.2/
4A that can
Specifications are at TA = 25°C
signal if the battery doesn’t respond to preconditioning. The
LT3651EUHE is available in a 36-lead (5mm × 6mm) QFN
surface mount package with two exposed thermal pads.
Design files for this circuit board are available at
http://www.linear.com/demo
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.
OPERATING PRINCIPLE
LT3651 is a complete Li-Ion battery charger, addressing
wide input voltage (6.5V to 32V) and high charge current
(up to 4A). High charging efficiency, as shown in Figure 1,
is produced with a constant frequency, average current
mode synchronous step-down switcher architecture.
The charger includes the necessary circuitry to allow for
programming and control of constant-current, constantvoltage (CC/CV) charging with
timer termination. High charging efficiency is achieved
by using a bootstrapped supply for low switch drop on
the high side driver and a MOSFET for the low side (synchronous) switch.
both current only and
Maximum charge current is set with an external sense
resistor in series with the inductor and is adjusted through
the RNG/SS pin. The total system input current is monitored with
constant input current by regulating battery charge current.
It is adjusted through the I
If the battery voltage is low, charge current automatically
reduces to 15% of the programmed current to provide
safe battery preconditioning. Once the battery voltage
climbs above the battery precondition threshold, the IC
automatically increases the maximum charging current
to the full programmed value
an input sense resistor and is used to maintain
pin.
LIM
.
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DEMO MANUAL DC1362A-A/-B
EFFICIENCY (%)
POWER LOSS (W)
86
4.4
OPERATING PRINCIPLE
Charge termination can occur when charge current decreases to one-tenth of the programmed maximum charge
current (C/10 termination). Alternately, termination can
be timer based through the use of an internal programmable charge cycle control timer. When using the timer
termination, charging continues beyond the C/10 level
to top off a battery. Charging typically terminates three
hours after
initiation. When the timer-based scheme is
used, bad battery detection is also supported. A system
fault is triggered if a battery stays in precondition mode
for more than one-eighth of the total charge cycle time.
Once charging is terminated and the LT3651 is not actively charging, the IC automatically enters a low current
standby mode in which supply bias currents are reduced
to <85µA
. If the battery voltage drops below 2.5% from the
full charge float voltage, the LT3651 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.
After charging is complete, the input bias current lines
connected to the battery are reduced to minimize battery
discharge.
The LT3651
contains provisions for a battery temperature
monitoring circuit. Battery temperature is monitored by
using an NTC thermistor located with the battery. If the
battery temperature moves outside the safe charging range
of 0°C to 40°C the charging cycle suspends and signals
a fault condition.
The LT3651 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.
A precision undervoltage lockout is possible by using a
resistor
divider on the shutdown pin (SHDN). The input
supply current is 17µA when the IC is in shutdown.
V
= 3.9
E
85
84
83
82
81
80
5
Figure 1. Efficiency and Power Loss vs V
FF
P
LOSS
10
20
15 25
VIN (V)
BAT
DC1362ab F01
30 32
4.0
3.6
3.2
2.8
2.4
2.0
IN
QUICK START PROCEDURE
Demonstration circuit 1362A-A/1362A-B is easy to set
up to evaluate the performance of the LT3651EUHE-4.2/
LT3651EUHE-4.1.
Using short twisted pair leads for any power connections,
with all loads and power supplies off
, refer to Figure 2 for
the proper measurement and equipment setup.
Follow the procedure below:
1. Jumper and power supply setting:
JP1 = RUN PS1 = OFF
JP2 = C/10 PS2 = OFF
2
2. Turn on PS2 and slowly increase the voltage to 2.7V while
monitoring the current into the BAT pin. If the current
is less than 5mA, turn on PS1. Increase the voltage on
PS1 to 4V while monitoring the input current. If the
current is less than 5mA, increase PS1 to 12V.
3. Verify that the battery charging current, IBAT is between
400mA and 600mA. The CHRG LED and ACPR LED
should be on and the FAULT LED should be off.
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QUICK START PROCEDURE
DEMO MANUAL DC1362A-A/-B
4. Increase PS2 until VBAT is 3.6V. Verify the input current IIN is between 1.4A and 1.7A, the battery current
IBAT is between 3.75A and 4.45A and that the CHRG
LED and ACPR LED are on.
5. Increase PS2 until VBAT is 4.25V. Verify the battery
charging current IBAT is less than 5mA and that the
CHRG LED and ACPR LED are off.
6. Decrease PS2 until VBAT is 3.9V. Verify the battery current IBAT is between 3.75A and 4.45A that the CHRG
LED and ACPR LED are 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 1.7A and 2.0A. Verify the voltage VNTC on the NTC turret is between 1.6V and 1.9V
and the voltage VRNG on the RNG/SS turret is between
450mV and 700mV. 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, CHRG LED and
ACPR LED are off.
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, CHRG LED and ACPR
LED are on.
10. Remove the jumper from NTC to ground. Verify the
charging current IBAT is between 3.75A and 4.45A
and that the FAULT LED is off and the CHRG LED and
ACPR LED are on.
11. Turn on LOAD1 and set to 1A. Verify the voltage V
SYSTEM
on the system voltage turret is approximately equal
.
to V
IN
12. Turn off PS1, PS2 and LOAD1.
NOTE: ALL CONNECTIONS FROM EQUIPMENT SHOULD BE KELVIN CONNECTED DIRECTLY TO THE BOARD PINS WHICH
THEY ARE CONNECTED TO ON THIS DIAGRAM AND ANY INPUT, OR OUTPUT, LEADS SHOULD BE TWISTED PAIR.
Figure 2. Proper Measurement Equipment Setup
DC1362ab F02
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DEMO MANUAL DC1362A-A/-B
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 C1 CAP, X7R, 1µF, 50V, 10%, 0805 MURATA, GRM21BR71H105KA12L
2 4 C3, C6, C11, C12 CAP, X7S, 10µF, 50V, 20%, 1210 TDK, C3225X7S1H106M
3 1 C4 CAP, X7R, 10µF, 10V, 10%, 0805 MURATA, GRM21BR71A106KE51L
4 3 C5, C7, C13 CAP, X5R, 0.68µF, 10V, 10%, 0402 MURATA, GRM155R61A684KE15D
5 1 C8 CAP, X5
6 1 D2 SMD, SCHOTTKY DIODE, SOT-23 CENTRAL SEMI, CMPSH1-4 TR
7 1 D6 DIODE, ZENER, 10V SOD-123 CENTRAL SEMI, CMHZ4697
8 1 L1 POWER INDUCTOR 3.3µH 20% 8.0A, 9mΩ 7mm × 7mm WURTH, 744314330
9 1 Q1 MOSFET, PCHANNEL, 40V, 25mΩ 1212-8 VISHAY, Si7611DN
10 1 R1 RES, CHIP, 0.015Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206LF-01-R015-F
11 1 R4 RES, CHIP, 0.024Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206LF-01-R024-F
12 2 R5, R12 RES, CHIP, 10k, 1/16W, 1%, 0402 VISHAY, CRCW040210K0FKED
13 1 R7 RES, CHIP, 44.2k, 1/16W, 1%, 0402 VISHAY, CRCW040244K2FKED
14 1 R8 RES, CHIP, 0.05Ω, 1/2W, 1%, 1206 IRC, LRC-LR1206LF-01-R050-F
15 1 R9 RES, CHIP, 147k, 1/16W, 1%, 0402 VISHAY, CRCW0402147KFKED
16 1 R13 RES, CHIP, 100k, 1/16W, 1%, 0402 VISHAY, CRCW0402100KFKED
17 1 U1 (-A VERSION)
U1 (-B VERSION)
Optional Electrical Components
1 1 C2 CAP, SMT, 22µF, 50V 20% SUNCON, 50CE22BS
2 2 C9, C10 CAP, CHIP, X7R, 0.022µF, ±10%, 16V, 0402 AVX, 0402YC223K AT2A
3 0 D1 SMD, SCHOTTKY, 5A, 40V DIODES INC, PDS540-13
4 1 D3 LED, RED PANASONIC, LNJ208R8ARA
5 2 D4, D5 LED, GREEN LITE-ON, LTST-C190KGKT
6 0 J1 HEADER, 3 PINS HIROSE ELECTRIC, DF3A-3P-2DSA
7 3 R2, R3, R10 RES, CHIP, 5.1k
8 0 R6, R11 RES, CHIP, 20k, 1/16W, 1%, 0402 VISHAY, CRCW040220K0FKED
Hardware for Demo Circuit
1 8 E1 TO E8 TESTPOINT, TURRET 0.095" MILL-MAX, 2501-2-00-80-00-00-07-0
2 2 JP1, JP2 2MM SINGLE ROW HEADER 3 PIN SAMTEC, TMM-103-02-L-S
3 2 JP1, JP2 SHUNT SAMTEC, 2SN-BK-G
4 4 MH1 TO MH4 STAND-OFF, NYLON 0.375" TALL (SNAP ON) KEYSTONE, 8832 (SNAP ON)
R, 100µF, 6.3V, 20%, 1210 TAIYO YUDEN, LMK325BJ107MM-T
4A HIGH VOLTAGE Li-ION BATTERY CHARGER LINEAR TECHNOLOGY, LT3651EUHE-4.2
TECHNOLOGY, LT3651EUHE-4.1
LINEAR
,1/4W, 5%, 1206 VISHAY, CRCW12065K10JNED
4
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SCHEMATIC DIAGRAM
DEMO MANUAL DC1362A-A/-B
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.
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DEMO MANUAL DC1362A-A/-B
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C ) 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 LT C 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 LT C 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.
LT C 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
Copyright © 2004, Linear Technology Corporation
6
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
dc1362aabfa
LT 0213 REV A • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 2012
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Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Analog Devices Inc.:
DC1362A-A DC1362A-B
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