Philips
Semiconductors
NE57606
2 to 4 cell redundant Lithium-ion
overcharge monitor
Product data
2002 Oct 10
INTEGRATED CIRCUITS
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2
2002 Oct 10
853-2296 27198
GENERAL DESCRIPTION
The NE57606 is a redundant overcharge detection IC for
use within 2-4 cell Li-ion battery packs. It detects the voltage
of each Li-ion cell and issues an overcharge signal which
then can be used to alert the portable host or be used to
turn-off a series charge MOSFET within the battery pack. Its
purpose is to act as a back-up protection circuit to a primary
Li-ion protection circuits such as the NE57605 and
NE57607. The overcharge signal is an open collector output
which can be wire-ORed with other safety functions.
FEATURES
Consumption current (V
CEL
= 3.8 V) 3.0
A typical
Consumption current (V
CEL
= 2.3 V) 0.3
A typical
Input current between cell pins (V
CEL
= 3.8 V)
0.3
A max
Overcharge detection voltage = threshold voltage
50 mV
Overcharge detection delay time (CT = 0.22
F) 1.5 s typical
Four voltage ranges available
APPLICATIONS
Li-ion Battery pack protection
SIMPLIFIED DEVICE DIAGRAM
SL01558
OV REF
V
C4
GND
OUT
OV REF
V
C3
OV REF
V
C2
OV REF
V
C1
0.7 V
V
CC
C
T
Voltage options
The device has 4 voltage options.
Part Number
Detection voltage
Hysteresis
NE57606Y
4.350 V
250 mV
NE57606C
4.225 V
None
NE57606D
4.130 V
None
NE57606E
4.450 V
100 mV
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
3
ORDERING INFORMATION
TYPE NUMBER
PACKAGE
TYPE NUMBER
NAME
DESCRIPTION
TEMPERATURE RANGE
NE57606YD
SO8
Small outline plastic, surface mount 8-pin
20 to +80
C
NE57606CD
SO8
Small outline plastic, surface mount 8-pin
20 to +80
C
NE57606DD
SO8
Small outline plastic, surface mount 8-pin
20 to +80
C
NE57606ED
SO8
Small outline plastic, surface mount 8-pin
20 to +80
C
PIN CONFIGURATION
SL01559
2
3
1
5
4
6
7
8
OUT
CT
GND
VC1
VC2
VC3
VC4
V
CC
PIN DESCRIPTION
Pin
No
Pin
Name
Function
1
OUT
Reset output pin
2
C
T
Delay capacitance pin
3
GND
Ground pin
4
VC1
Cell 1 power supply
5
VC2
Cell 2 power supply
6
VC3
Cell 3 power supply
7
VC4
Cell 4 power supply
8
V
CC
Voltage supply to IC
MAXIMUM RATINGS
Symbol
Parameter
Min
Max
Unit
V
CC
V
CC
input voltage
0.3
+24
V
VC2
V4 input voltage (Note1)
0.3
+24
V
VC3
V3 input voltage (Note1)
0.3
+24
V
VC4
V2 input voltage (Note1)
0.3
+24
V
VC1
V1 input voltage (Note1)
0.3
+24
V
V
CT
CT pin voltage
0.3
+24
V
OUT
V
OUT
pin voltage
0.3
+24
T
STG
Storage Temperature
40
+125
C
T
amb
Operating temperature
20
+80
C
Pd
Power dissipation
300
mW
NOTES:
1. V
CC
= >V4 = > V3 = > V2 = > V1 = > 0.3
2. A current no greater than 100
A should be passed through pin Ct.
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
4
ELECTRICAL CHARACTERISTICS
T
amb
= 25
C, V
CEL
= V4V3 = V3V2 = V2V1 = V1GND, V
CC
= 4V
CEL
, except where noted otherwise
Symbol
Parameter
Conditions
Min
Typ
Max
Units
I1
Consumption current 1
V
CEL
= 3.8 V
3.0
6.0
A
I2
Consumption current 2
V
CEL
= 2.3 V
0.3
0.5
A
I3
Pin I/O current between cells
V
CEL
= 3.8 V (V4, V3, V2, V1 side)
0.0
0.3
A
V
S
Overcharge detection voltage
V
CEL
= L
H, Ta = 20~+70
C
NE57606Y
4.30
4.350
4.40
V
NE57606C
4.175
4.225
4.174
NE57606D
4.080
4.130
4.180
NE57606E
4.400
4.450
4.500
HSY
Hysteresis voltage
V
CEL
= L
H
L
0.20
0.25
0.30
V
T
PLH
Overcharge detection delay time
C
T
= 0.22
F
1.0
1.5
2.0
S
V
OL
Output voltage L
I
L
= 100
A
0.4
V
I
LEAK
Output leakage current
V
CEL
= 3.8 V, V
OUT
= 24 V
0.1
A
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
5
TECHNICAL DISCUSSION
The NE57606 is typically used in conjunction with a Li-ion protection
IC as redundant protection for a 2, 3, or 4-cell lithium-ion battery
pack. Lithium-ion cells can present a safety hazard if they become
overcharged, therefore careful monitoring of each cell's operating
point is necessary. For very safety-sensitive applications, a back-up
protection circuit using a device such as the NE57606 is advisable.
The NE57606 monitors each cell within a 2-4 Li-ion cell battery
pack. If any cell within the battery pack exceeds the full-charge
threshold voltage, the overvoltage fault status output assumes a low
state. This output signal should be used to alert other parts of the
system that an overcharged state has been reached. This output
could also be used to open a MOSFET placed in series with the
positive battery terminal to interrupt the charging current from the
battery charger.
Redundant Protection of a Lithium-ion Battery
Pack
Within a typical Li-ion battery system, there are two or three major
circuits responsible for the monitoring and maintenance of the Li-ion
cells: the Li-ion battery charger, the Li-ion protection circuit, and
sometimes the redundant Li-ion overcharge detector. This type of
system is called a triple-redundant protected system. If any one of
the protection circuits fail, then there will be two other independent
systems to assume the protection function. If the product is
designed properly, that is, component de-rating, non-cascading
failure modes, ESD, packaging, etc, having two or more
simultaneous failures within the protection system is virtually
impossible.
During normal operation of the Li-ion system, the battery charger
should be the circuit that terminates the charge. The Lithium-ion
protection circuit should never be used for routine termination of the
charging function. It should be viewed as a back-up protection
system in the event of a charger failure. The redundant overcharge
detection IC should disconnect the pack from the charger in the
event that both other systems have failed.
Setting the trip-point voltages are key to the system's operation.
First, the trip point tolerances should not overlap, or the systems will
not become active in the proper order over large production. The trip
points should be typically set in the following fashion:
1. The battery charger should be set to terminate its charge at a
point just below the cell's full charge voltage (1%)
2. The Li-ion protection circuit is set to open the series charge
MOSFET switch at the rated full charge voltage of any of the
cell(s). (
1%)
3. The redundant overcharge detector is set to issue an alert and/or
disconnect a series charge MOSFET switch when any cell
voltage exceeds the rated full charge voltage (+1%)
With trip-points set as described above, the charger will taper its
charging current until the charging current falls below a certain
current level, after which the charger turns off. Only if the charger
does not or cannot terminate the charging, the protection IC will
open a series MOSFET switch, thus cutting off any charge current.
Lastly, if both the charger and the protection IC were to fail, the
NE57606 will open another series MOSFET.
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
6
APPLICATION INFORMATION
The NE57606 can be used within 2, 3, or 4-cell battery packs. This
can be done by electrically creating a short-circuit across the pins
that would have been connected to the ends of the cells. For a 3-cell
pack pin VC1 should be connected to ground (pins 3 to 4). All of the
combinations are shown in Table 1.
Table 1.
Cells
VC1
VC2
VC3
VC4
4-cell
VC1
VC2
VC3
VC4
3-cell
VC1
VC1
VC2
VC3
2-cell
VC1
VC1
VC1
VC2
The schematics for a 3-cell and a 4-cell monitoring circuit are shown
in Figures 1 and 2 respectively.
C3
C2
C1
OVERVOLTAGE
FAULT (OPEN
COLLECTOR)
SL01560
V
CC
NE57606
C
DLY
0.1
F
1 k
0.1
F
10 k
0.1
F
10 k
V
C4
V
C3
V
C2
V
C1
100
V+
V
0.1
F
OUT
GND
1
2
3
4
5
6
7
8
0.22
F
Figure 1. 3-cell monitoring circuit
SL01561
C4
C3
C2
OVERVOLTAGE
FAULT (OPEN
COLLECTOR)
V
CC
C
DLY
0.1
F
1 K
0.1
F
10 K
0.1
F
10 K
V
C4
V
C3
V
C2
V
C1
100
V+
V
0.1
F
OUT
GND
1
2
3
5
6
7
8
0.22
F
C1
0.1
F
10 K
4
NE57606
Figure 2. 4-cell monitoring circuit
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
7
Using the NE57606 within a Li-ion battery system
A Li-ion and Li-polymer 4-cell battery system using the NE57605
and the NE57606 is shown in Figures 3 and 4.
The circuit in Figure 3 shares the charge MOSFET between the ICs.
This is sometimes not acceptable since a failure of the charge
MOSFET or its associated drive circuitry can disable protection
provided by the second circuit.
SL01562
C4
C3
C2
V
CC
C
DLY
0.1
F
1 k
0.1
F
10 k
0.1
F
10 k
V
C4
V
C3
V
C2
V
C1
100
0.1
F
OUT
GND
1
2
3
5
6
7
8
0.22
F
C1
0.1
F
10 k
4
DISCHARGE
FET
CHARGE
FET
47 k
10 k
10 k
V+
330
V
CC
DF
CS
CF
910 k
NE57605
C
DLY(UV)
C
DLY(OV)
C
DLY(OC)
V
CON
GND
0.1
F
V
C3
0.1
F
1 k
0.1
F
1 k
0.1
F
1 k
V
C2
V
C1
SYSTEM GROUND
0.1
F
330
NE57606
SEL
V
C4
1
7
9
8
13
10
15
16
17
18
11
20
5
3
Figure 3. Shared charge MOSFET
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
8
SL01862
C4
C3
C2
V
CC
C
DLY
0.1
F
1 k
0.1
F
10 k
0.1
F
10 k
V
C4
V
C3
V
C2
V
C1
100
0.1
F
OUT
GND
1
2
3
5
6
7
8
0.22
F
C1
0.1
F
10 k
4
DISCHARGE
FET
CHARGE
FET
47 k
10 k
10 k
V+
330
V
CC
DF
CS
CF
910 k
NE57605
C
DLY(UV)
C
DLY(OV)
C
DLY(OC)
V
CON
GND
0.1
F
V
C3
0.1
F
1 k
0.1
F
1 k
0.1
F
1 k
V
C2
V
C1
SYSTEM GROUND
0.1
F
330
NE57606
SEL
V
C4
1
7
9
8
13
10
15
16
17
18
11
20
5
3
REDUNDANT
CHARGE
FET
10 k
10 k
910 k
CHARGE SHUTDOWN
Figure 4. Double-redundantly protected 4-cell Li-ion battery pack (completely redundant system)
The circuit in Figure 4 shows how to implement a completely
isolated design. None of the components are shared and a failure in
any part of one circuit will not affect the operation of the other. By
also not sharing input noise filter components, the failure of the IC
due to an input failure or an open circuit will not affect the protection
provided by the other circuit.
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
9
PACKING METHOD
SL01305
TAPE DETAIL
COVER TAPE
CARRIER TAPE
REEL
ASSEMBLY
TAPE
GUARD
BAND
BARCODE
LABEL
BOX
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
10
SO8:
plastic small outline package; 8 leads; body width 3.9 mm
1.73
0.068
0.51
0.33
0.013
0.020
B
2
4.95
4.80
0.189
0.195
1.27
0.38
0.050
0.015
0.076
0.003
SO8
pin 1 index
4.95
4.80
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
11
REVISION HISTORY
Rev
Date
Description
_1
20021010
Product data; initial version.
Engineering Change Notice 853-2296 27198 (date: 20021003).
Philips Semiconductors
Product data
NE57606
2 to 4 cell redundant Lithium-ion overcharge monitor
2002 Oct 10
12
Purchase of Philips I
2
C components conveys a license under the Philips' I
2
C patent
to use the components in the I
2
C system provided the system conforms to the
I
2
C specifications defined by Philips. This specification can be ordered using the
code 9398 393 40011.
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.
Limiting values definition -- 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
via a Customer Product/Process Change Notification (CPCN). Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys
no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent,
copyright, or mask work right infringement, unless otherwise specified.
Contact information
For additional information please visit
http://www.semiconductors.philips.com.
Fax: +31 40 27 24825
For sales offices addresses send e-mail to:
sales.addresses@www.semiconductors.philips.com.
Koninklijke Philips Electronics N.V. 2002
All rights reserved. Printed in U.S.A.
Date of release: 10-02
Document order number:
9397 750 08992
Philips
Semiconductors
Data sheet status
[1]
Objective data
Preliminary data
Product data
Product
status
[2] [3]
Development
Qualification
Production
Definitions
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.
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.
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).
Data sheet status
[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.
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I
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