NE57611 [NXP]
Single cell Li-ion battery charger; 单节锂离子电池充电器型号: | NE57611 |
厂家: | NXP |
描述: | Single cell Li-ion battery charger |
文件: | 总12页 (文件大小:130K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
INTEGRATED CIRCUITS
NE57611
Single cell Li-ion battery charger
Product data
2003 Oct 15
Supersedes data of 2002 Dec 10
Philips
Semiconductors
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
DESCRIPTION
The NE57611 is a one-cell, Li-ion battery charger controller which
includes constant-current and constant voltage charging, a precise
charge termination, and precharging of undervoltage cells.
It contains the minimum circuitry needed to safely charge a
lithium-ion or lithium-polymer cell. This makes it good for very
compact, portable applications.
FEATURES
APPLICATIONS
• 30 mV per cell charging accuracy from 0 °C to +50 °C
• Cellular telephones
• Low quiescent current (250 µA – ON; 2 µA – OFF)
• Undervoltage precharge detector
• Personal Digital Assistants
• Other 1-cell Li-ion portable applications
• Self-discharge maintenance charging
SIMPLIFIED SYSTEM DIAGRAM
R
UV
BC807
BAL74
10 kΩ
PBYR
240CT
BATTERY PACK
V+
BCP51
+V
IN
1 kΩ
150 Ω
3
7
6
LV
DRV
V
CELL
8
1
V
CC
Li-ION
CELL
10 µF
10 µF
NE57611
ON/OFF
V
LVEN
2
CS
SS
4
5
–V
IN
R
V–
CS
SL01661
Figure 1. Simplified system diagram.
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
ORDERING INFORMATION
PACKAGE
TEMPERATURE
RANGE
TYPE NUMBER
NAME
DESCRIPTION
NE57611BDH
VSOP-8A (TSSOP)
plastic thin shrink small outline package; 8 leads; body width 4.4 mm
–20 to +70 °C
PIN CONFIGURATION
PIN DESCRIPTION
PIN SYMBOL
DESCRIPTION
ON/OFF control input pin for the IC.
TOP VIEW
ON/OFF
LVEN
LV
1
2
3
4
8
7
6
5
V
1
2
3
ON/OFF
LVEN
LV
CC
ON/OFF = V : OFF
CC
DRV
ON/OFF = GND: ON
V
CELL
Low voltage detection circuit ON/OFF control.
V
CS
SS
LVEN = V : OFF
CC
SL01660
LVEN = GND: ON
Figure 2. Pin configuration.
Low cell voltage detection circuit output pin.
Open collector; Active-LOW.
4
5
V
Connect to negative pole of battery.
Current detection pin.
SS
CS
Detects current by drop in external resistor
voltage and controls rated current.
Current value can be set at 0.1 V/R1 typ.
Battery voltage input pin.
6
V
CELL
Detects battery voltage and controls rated
voltage to the prescribed voltage value.
7
8
DRV
Charging control output pin drives external
PNP-Transistor to control charging.
V
CC
Power supply input pin.
MAXIMUM RATINGS
SYMBOL
PARAMETER
MIN.
–0.3
–0.3
–0.3
–0.3
–20
–40
–
MAX.
+18
UNIT
V
V
V
V
V
Power supply voltage
Maximum cell voltage
LVEN input voltage
ON/OFF input voltage
CC(max)
CEL(max)
LVEN
+13
V
V
V
+ 0.3
V
CC
CC
+ 0.3
V
ON/OFF
T
opr
Operating ambient temperature
Storage temperature
+70
°C
°C
mW
T
stg
+125
300
P
D
Power dissipation
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
ELECTRICAL CHARACTERISTICS
T
amb
= 25 °C, V = 5 V, unless otherwise specified.
IN
SYMBOL
PARAMETER
Consumption current 1
CONDITIONS
MIN.
–
TYP.
250
2
MAX.
400
UNIT
µA
µA
V
I
I
ON/OFF = LVEN = 0 V (Charge: ON)
CC1
CC2
Consumption current 2
Output voltage 1
Output voltage 2
Current limit
ON/OFF = LVEN = V
(Charge: OFF)
–
10
CC
V
OV1
V
OV2
V
CL
T
= 25 °C
4.100
4.095
90
4.125
4.125
100
5.0
4.150
4.155
110
amb
T
amb
= 0 °C to 50 °C
V
mV
µA
I
Leakage current between V
during operation
-CS
CELL
3.0
7.0
CEL1
I
I
Leak current between V
ON/OFF input current
ON/OFF input voltage L
-CS
V = 0 V or OPEN
CC
–
–
0.01
20
–
1
µA
µA
V
CEL2
CELL
30
2.0
ON/OFF
V
V
V
Charge: ON
Charge: OFF
–0.3
L1
ON/OFF input voltage H
V
V
– 1.0
–
V
+ 0.3
CC
V
H1
CC
Low voltage detection voltage
LVEN input current
2.0
2.15
20
–
2.3
V
UV(CELL)
LVEN
I
–
30
µA
V
V
V
LVEN input voltage L
LVEN input voltage H
Low voltage detection
Low voltage detection circuit: ON
Low voltage detection circuit: OFF
–0.3
2.0
L2
– 1.0
–
V
+ 0.3
CC
V
H2
CC
I
LV
–
–
–
0.5
0.4
µA
V
V
output leak current Low voltage
detection
I
= 1 mA
0.2
LV
SINK
I
output saturation voltage DRV pin
inflow current
10
20
–
–
mA
V
DRV
V
DRV pin output voltage
For no load
0.3
V
CC
– 0.3
DRV
NOTES:
1. Please insert a capacitor of several µF between power supply and ground when using.
2. Be sure that CS pin potential does not fall below –0.5 V.
3. If the IC is damaged and control is no longer possible, its safety cannot be guaranteed. Please protect with something other than this IC.
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
as that provided by the NE57611. This provides two levels of
TECHNICAL DISCUSSION
overcharge protection, with the primary protection of the external
charge control circuit and the back-up protection from the battery
pack’s protection circuit. The charge termination circuit will be set to
stop charging at a level around 50 mV less than the overvoltage
threshold voltage of the battery pack’s own protection circuit.
Lithium cell safety
Lithium-ion and lithium-polymer cells have a higher energy density
than that of nickel-cadmium or nickel metal hydride cells and have a
much lighter weight. This makes the lithium cells attractive for use in
portable products. However, lithium cells require a protection circuit
within the battery pack because certain operating conditions can be
hazardous to the battery or the operator, if allowed to continue.
Lithium cell operating characteristics
The internal resistance of lithium cells is in the 100 mΩ range,
compared to the 5–20 mΩ of the nickel-based batteries. This makes
the Lithium-ion and polymer cells better for lower battery current
applications (less than 1 ampere) as found in cellular and wireless
telephones, palmtop and laptop computers, etc.
Lithium cells have a porous carbon or graphite anode where lithium
ions can lodge themselves in the pores. The lithium ions are
separated, which avoids the hazards of metallic lithium.
If the lithium cell is allowed to become overcharged, metallic lithium
plates out onto the surface of the anode and volatile gas is
generated within the cell. This creates a rapid-disassembly hazard
The average operating voltage of a lithium-ion or polymer cell is
3.6 V as compared to the 1.2 V of NiCd and NiMH cells. The typical
discharge curve for Lithium cell is shown in Figure 3.
(the battery ruptures). If the cell is allowed to over-discharge (V
less than approximately 2.3 V), then the copper metal from the
CELL
cathode goes into the electrolyte solution. This shortens the cycle
life of the cell, but presents no safety hazard. If the cell experiences
excessive charge or discharge currents, as happens if the wrong
charger is used, or if the terminals short circuit, the internal series
resistance of the cell creates heating and generates the volatile gas
which could rupture the battery.
V
4.0
3.0
OV
The protection circuit continuously monitors the cell voltage for an
overcharged condition or an overdischarged condition. It also
continuously monitors the output for an overcurrent condition. If
any of these conditions are encountered, the protection circuit opens
a series MOSFET switch to terminate the abnormal condition. The
lithium cell protection circuit is placed within the battery pack very
close to the cell.
V
UV
2.0
50
NORMALIZED CELL CAPACITY (%)
100
Charging control versus battery protection
The battery pack industry does not recommend using the pack’s
internal protection circuit to end the charging process. The external
battery charger should have a charge termination circuit in it, such
SL01662
Figure 3. Lithium discharge curve.
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
The charger IC begins charging with a current that is typically the
rating of the cell (1C) or the milliampere rating of the cell. As the cell
Charging Lithium cells
The lithium cells must be charged with a dedicated charging IC such
as the NE57600. These dedicated charging ICs perform a
current-limited, constant-voltage charge, as shown in Figure 4.
approaches its full-charge voltage rating (V ), the current entering
OV
the cell decreases, and the charger IC provides a constant voltage.
When the charge current falls below a preset amount, 50 mA for
example, the charge is discontinued.
If charging is begun below the overdischarged voltage rating of the
cell, it is important to slowly raise the cell voltage up to this
overdischarged voltage level. This is done by a reconditioning
charge. A small amount of current is provided to the cell (50 mA for
example), and the cell voltage is allowed a period of time to rise to
the overdischarged voltage. If the cell voltage recovers, then a
normal charging sequence can begin. If the cell does not reach the
overdischarged voltage level, then the cell is too damaged to charge
and the charge is discontinued.
1.0
0.5
CONSTANT
CURRENT
CONSTANT
VOLTAGE
To take advantage of the larger energy density of lithium cells it is
important to allow enough time to completely charge the cell. When
the charger switches from constant current to constant voltage
charge (Point B, Figure 4) the cell only contains about 80 percent of
its full capacity. When the cell is 100 mV less than its full rated
charge voltage the capacity contained within the cell is 95 percent.
Allowing the cell to slowly complete its charge takes advantage of
the larger capacity of the lithium cells.
1.0
2.0
TIME (HOURS)
V
OV
4.0
3.0
Point B
2.0
1.0
TIME (HOURS)
SL01663
Figure 4. Lithium cell charging curves.
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
The charger circuit then responds in the following manner if the
battery pack voltage is:
NE57611 CHARACTERISTICS
The NE57611 is a precise linear-mode battery charger with a cell
undervoltage detector. It contains the minimum circuitry needed to
safely charge a lithium-ion or lithium-polymer cell. This makes it
good for very compact, portable applications.
1. <2.15 V (V ): The LV pin (open collector) assumes a LOW state
LV
which enables an external precharge circuit. The precharge
circuit then charges the undervoltage cell with a very low current
(1 – 5 mA) to bring the cell voltage up to a voltage greater than
The charging process is permitted to start when the DC input
V . This may take a long time depending upon the depth of the
LV
voltage is greater than V , the battery voltage is less than the
IN(min)
overdischarge.
overvoltage point (V ), and the ON/OFF pin is LOW. The cell
OV
voltage is continuously monitored by the charge controller and will
fall into one of three voltage ranges:
2. 2.15 V < V
< 4.35 V (V ): The normal charge current is
CELL
OV
placed into the battery pack. During this time, the charge
controller charges the cell with a constant current as set by the
1. If the cell has been severely discharged or allowed to sit on the
shelf for a long period of time, the cell will be in the undervoltage
range, which is less than 2.3 V.
value of R . When the cell voltage approaches the overvoltage
CS
threshold, the charging current begins to decrease until the
cell voltage reaches the overvoltage termination voltage. This
portion of the charge process is called constant voltage charge.
2. If the cell has only been partially discharged then the voltage will
fall into the normal range.
3. V
> 4.35 V (V ): The charge current tapers down to zero
OV
CELL
3. If the cell has inadvertently been overcharged and is being
reconnected to the charger, the cell is in the overcharged range.
and the charging is discontinued. Some small current will
continue to flow into the cell to replace any self-discharge losses
within the cell, but will not overcharge the cell.
V
DRV
7
LV
LVEN
V
CELL
CC
8
3
2
6
V
CELL
UNVERVOLTAGE
COMPARATOR
1
ON/OFF
CHARGE
TERMINATION
COMPARATOR
V
CC
UNVERVOLTAGE
DETECTOR
1.2 V
CHARGE
CURRENT
COMPARATOR
5
4
CS
GND
SL01664
Figure 5. Functional diagram.
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
APPLICATION INFORMATION
R
UV
BC807
BAL74
10 kΩ
PBYR
240CT
BATTERY PACK
V+
BCP51
+V
IN
1 kΩ
150 Ω
3
7
6
LV
DRV
V
CELL
8
V
CC
Li-ION
CELL
10 µF
10 µF
NE57611
1
ON/OFF
V
LVEN
2
CS
SS
4
5
–V
IN
R
V–
CS
SL01661
Figure 6. Typical charger circuit.
Figure 6 shows the typical implementation of a single-cell
Lithium-ion battery charger using the NE57611.
maximum. This requirement would also include the troughs of
any ripple voltage riding atop the DC input voltage from a poorly
filtered wall transformer.
Setting the reconditioning charge current
2. The maximum input voltage must not exceed the voltage ratings
of the components in the charging circuit.
This charging current is needed when the cell voltage is less than
2.15 V. The current is limited by R and its approximate value
UV
should be calculated by:
3. The power rating and the thermal design of the linear pass
transistor must be able to withstand the maximum experienced
headroom voltage at the rated normal charge current. The worst
case condition can be calculated by assuming the cell is at its
lowest voltage (typically 2.3 V) and the input voltage is at its
highest point in its range (typically the DC voltage created at the
highest AC input).
R
= [V
– V
] / I
CELL(min) chg(recond)
UV
in(max)
The reconditioning current should be 1 to 5 mA.
To set the normal maximum charging current, first determine the
desired charge rate for the particular lithium cell in use within the
battery pack. The cell’s datasheet should provide the recommended
maximum rate of charge. Charging at this rate should completely
charge the cell in under 3 hours.
The power can then be calculated by:
P
= (V
– V
) (I
charge
)
D(max)
IN(max)
CELL(min)
The value of R that regulates the normal charging current can be
found by:
CS
The criteria for the selection of the PNP power transistor should be:
> 1.5 V
V
CEO
IN(max)
charge
R
= 0.1 V / I
chg(normal)
CS
I > 1.5 I
c
h
P
> 50 @ 1 Amp
> P
D(max)
FE
Designing the power section of the battery charger
There are several factors that are important to the design of a
reliable Li-ion battery charger system. These major factors are:
D
The choice of power package should be done with the highest
possible power dissipation and at the highest expected ambient
temperature. One can choose a package by referring to Figure 7
and drawing two intersecting lines from the appropriate points on the
X and Y axis.
1. The input voltage must not fall below the cell voltage plus the
headroom voltage of the charger circuit. The headroom voltage
for the charger circuit is 0.6 V, which would make the minimum
input voltage about 5.0 V for a Li-ion cell rated at 4.3 V
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
Placing the overvoltage thresholds
For safety and reliability, the lithium-ion protection circuit inside the
battery pack should not be used to terminate the charging process
routinely. The protection circuit should only activate when the
charger has failed. Therefore, the full-charge termination voltage
should be set lower than the overvoltage trip threshold of the
protection circuit. To assure that the protection circuit never trips
routinely, the charger termination voltage should be set below the
sum of the two voltage accuracy tolerances of the protection circuit
and the charger. This would be about 50 – 55 mV below.
2
D2PAK
DPAK
1
SOT223
SOT23
Design-related safety issues
In designing charging circuits for lithium-ion and polymer cells, the
designer should provide for user mishandling, common
environmental hazards and for random component failures. Some of
the user-related issues are plugging the battery pack into the
charger backwards, live insertion of the battery into the charger and
the charger into the input voltage source. A reverse biased diode is
typically provided for the reversed battery. This shunts the reverse
currents away from the IC thus protecting the functionality of the
charger. To protect against live insertion of battery and input power
source, check the sequence of how the circuit powers-up to make
sure that there are no sequences that can lead to a failure or
hazardous condition.
25
50
75
100
MAXIMUM AMBIENT TEMPERATURE (°C)
SL01665
Figure 7. Pass transistor surface mount packages using the
minimum recommended footprint.
This chart gives the power transistor package one can use if the
minimum recommended pad size is used under the power part. If a
larger copper pad is provided under the power device, the power
handling capability of the part can be increased without sacrificing its
reliability. Table 1 shows how to dissipate more power in a smaller
part.
A common adverse operating condition is lightning caused
transients. A 500 mW zener diode across the input terminals
handles positive and negative transients caused by lightning. The
zener will fail short-circuited, if the energy exceeds its surge energy
ratings. To help protect the protection zener, place a small inductor
or low value resistor in series from the input source. This will lower
the peak voltage and energy and distribute it over a longer period.
Table 1. Power handling capability
Given for F4 fiberglass PCB with 2 oz. copper
Pad Size
2X
R
Power increase (%)
th(j-a)
0.88 K/W
0.80 K/W
0.74 K/W
0.70 K/W
14%
25%
35%
43%
3X
4X
5X
NOTE:
Going beyond five times the minimum recommended footprint yields
diminishing improvements to the thermal performance.
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2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
PACKING METHOD
The NE57611 is packed in reels, as shown in Figure 8.
GUARD
BAND
TAPE
TAPE DETAIL
REEL
ASSEMBLY
COVER TAPE
CARRIER TAPE
BARCODE
LABEL
BOX
SL01305
Figure 8. Tape and reel packing method.
10
2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
VSOP-8A: plastic small outline package; 8 leads; body width 4.4 mm
A
1.35
1.15
0.23 0.16
0.21 0.10
3.4
2.8
4.6
4.2
6.7
6.1
0.7
0.3
0.875
max.
10°
0°
1.15
0.12
VSOP-8A
11
2003 Oct 15
Philips Semiconductors
Product data
Single cell Li-ion battery charger
NE57611
REVISION HISTORY
Rev
Date
Description
_2
20031015
Product data (9397 750 12181). ECN 853–2330 30445 of 14 October 2003.
Supersedes data of 2002 Dec 10 (9397 750 10171).
Modifications:
• Pin numbering corrected in Figures 1, 2, 5, and 6 and ‘Pin description’ table on page 3.
_1
20021210
Product data (9397 750 10171); initial version. ECN 853–2330 27919 of 25 March 2002.
Data sheet status
Product
status
Definitions
[1]
Level
Data sheet status
[2] [3]
I
Objective data
Development
This data sheet contains data from the objective specification for product development.
Philips Semiconductors reserves the right to change the specification in any manner without notice.
II
Preliminary data
Qualification
Production
This data sheet contains data from the preliminary specification. Supplementary data will be published
at a later date. Philips Semiconductors reserves the right to change the specification without notice, in
order to improve the design and supply the best possible product.
III
Product data
This data sheet contains data from the product specification. Philips Semiconductors reserves the
right to make changes at any time in order to improve the design, manufacturing and supply. Relevant
changes will be communicated via a Customer Product/Process Change Notification (CPCN).
[1] Please consult the most recently issued data sheet before initiating or completing a design.
[2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL
http://www.semiconductors.philips.com.
[3] For data sheets describing multiple type numbers, the highest-level product status determines the data sheet status.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see
the relevant data sheet or data handbook.
Limitingvaluesdefinition— Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one or more of the limiting
values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given
in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no
representation or warranty that such applications will be suitable for the specified use without further testing or modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be
expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree
to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes in the products—including circuits, standard cells, and/or software—described
or contained herein in order to improve design and/or performance. When the product is in full production (status ‘Production’), relevant changes will be communicated
viaaCustomerProduct/ProcessChangeNotification(CPCN).PhilipsSemiconductorsassumesnoresponsibilityorliabilityfortheuseofanyoftheseproducts,conveys
nolicenseortitleunderanypatent, copyright, ormaskworkrighttotheseproducts, andmakesnorepresentationsorwarrantiesthattheseproductsarefreefrompatent,
copyright, or mask work right infringement, unless otherwise specified.
Koninklijke Philips Electronics N.V. 2003
Contact information
All rights reserved. Printed in U.S.A.
For additional information please visit
http://www.semiconductors.philips.com.
Fax: +31 40 27 24825
Date of release: 10-03
9397 750 12181
For sales offices addresses send e-mail to:
sales.addresses@www.semiconductors.philips.com.
Document order number:
Philips
Semiconductors
相关型号:
NE576D-T
IC COMPANDER, PDSO14, 3.90 MM, PLASTIC, MS-012AB, SOT-108-1, SOP-14, Analog Computational Function
NXP
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