NE57610EDH [NXP]
Li-ion battery charger control with adjustable thresholds; 锂离子电池充电器控制与调节的阈值
| 型号： | NE57610EDH |
| 厂家： | 
NXP |
| 描述： | Li-ion battery charger control with adjustable thresholds |
| 文件： | 总16页 (文件大小：188K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
INTEGRATED CIRCUITS
NE57610
Li-ion battery charger control
with adjustable thresholds
Product data
2002 Nov 05
Philips
Semiconductors
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
DESCRIPTION
The NE57610 is a one- or two-cell, Li-ion battery charger controller
which includes: constant-current and constant-voltage charging, a
precise charge termination, pre-charging of undervoltage cells,
overcharge timer, and under- and over-temperature detection.
The NE57610 is available in the very small TSOP-24A package.
FEATURES
APPLICATIONS
• 30 mV per cell charging accuracy from 0 °C to +50 °C
• Controls charging of Lithium-ion batteries
• Low quiescent current
• Undervoltage pre-charge conditioning and timer
• Battery overtemperature detection and protection
• Input voltage OK detection
• Self-discharge maintenance charging
• Overcharge timer
• LED drivers
SIMPLIFIED SYSTEM DIAGRAM
PBYR
240CT
BATTERY PACK
R
V+
CS
BCP51
+V
in
150 Ω
18
17
DRV
15
CS
V
RED
GRN
CC
13
BAT1
BAT2
14
CELL 2
CDLL 1
22
21
3
4
RED
GRN
TP1
TP2
TP1
TP2
10 µF
NE57610
23
5
V
REF
OSC1
R
OSC
24
12
THERM
OSC2
TMP
ON/OFF RESET GND PGND
2
1
6
7
C
T
–V
in
V–
SL01863
Figure 1. Simplified system diagram.
2
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
ORDERING INFORMATION
PACKAGE
TEMPERATURE
RANGE
TYPE NUMBER
NAME
DESCRIPTION
NE57610BDH
NE57610EDH
NE57610YDH
TSOP24A
TSOP24A
TSOP24A
24-pin thin small outline
24-pin thin small outline
24-pin thin small outline
–20 °C to +70 °C
–20 °C to +70 °C
–20 °C to +70 °C
Voltage options
Part number
Output voltage
Over-voltage detection threshold
Cells
2-cell
1-cell
1-cell
NE57610BDH
NE57610EDH
NE57610YDH
8.4 V
4.2 V
4.1 V
8.7 V
4.35 V
4.35 V
MAXIMUM RATINGS
SYMBOL
PARAMETER
Min.
Max.
UNIT
V
V
Power supply voltage
Ambient temperature
Storage temperature
Power dissipation
–0.3
–20
–40
–
15
+70
+125
250
CC(max)
T
°C
amb
T
stg
°C
P
D
mW
PIN CONFIGURATION
ON/OFF
RESET
TP1
1
2
3
4
5
6
7
8
9
24 OSC2
23 OSC1
22 R_LED
21 G_LED
20 VINOK
19 ADJ5
TP2
V
REF
GND1
GND2
ADJ1
ADJ2
NE57610
18
V
CC
17 DRV
16 COMP
15 CS
ADJ3 10
ADJ4 11
TEMP 12
14 BAT2
13 BAT1
SL01846
Figure 2. Pin configuration.
3
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
PIN DESCRIPTION
PIN
1
SYMBOL
ON/OFF
RESET
I/O
DESCRIPTION
I
I
ON/OFF: When LOW, the charger operates. When HIGH, it inhibits all functions of the charger.
2
RESET: In a LOW state all charger functions are enabled. When the pin is brought HIGH, all of the charger
functions are inhibited and when brought to a LOW state again, all of the timers are initialized and the start-up
functions are enabled.
3
4
5
TP1
TP2
O
O
O
Test Point 1: This pin is the output of the center counter of the pre-charger timer counter. This pin will slowly
toggle between a HIGH state and a LOW state during the pre-charge period.
Test Point 2: This pin is the output of the center counter in the high-rate charger counter. This pin will slowly
toggle between a HIGH state and a LOW state during the high-rate charging period.
V
REF
Reference voltage: This is an output of a temperature stabilized 1.2 V reference. It is used in the bias of the
thermocouple and for adjustment of the ADJ1–ADJ4 pins.
6
7
8
GND1
GND2
ADJ1
–
–
I
Ground.
Ground.
Overcurrent threshold adjustment pin: This pin is internally set to 1.16 V. The overvoltage trip point is set
too high at this voltage to become active. This is useful where the input power source is a current-limited wall
transformer. It may be adjusted by referring to ‘Use of the ADJ1–ADJ4 pins’.
9
ADJ2
I
Charge termination current threshold adjustment pin: At the top-of-charge, when the charge current falls
below this level, the charging cycle is terminated. This pin is internally set to 62 mV. It may be adjusted by
referring to ‘Use of the ADJ1–ADJ4 Pins’.
10
11
ADJ3
ADJ4
I
I
Pre-charge current adjustment pin: This adjusts the amount of current entering the battery during the
pre-charge period. It is internally set to 120 mV. It may be adjusted by referring to ‘Use of the ADJ1–ADJ4 Pins’.
High-rate current adjustment pin: This pin controls the amount of charge current during the high-rate of
charge period. The pin is internally set to 89 mV. It may be adjusted by referring to ‘Use of the ADJ1–ADJ4
Pins’.
12
TEMP
I
Battery temperature sensing pin: This pin inhibits the charging process if the voltage presented to this pin
falls outside an acceptable temperature range. The external voltage is created by resistor network that includes
a thermocouple.
13
14
BAT1
BAT2
I
I
Battery voltage sensing pin: This pin senses the battery voltage.
Battery voltage and current sensing pin: This pin senses battery voltage but also is one of the two leads
for sensing charging current. (CS is the other current sensing pin.)
15
16
CS
I
I
Current sensing pin: This pin is one of the two current sensing pins. (BAT2 is the other pin.)
COMP
Current regulation amplifier compensation pin: It is recommended that around 100 pF be connected
between this pin and the DRV pin. This capacitor improves the phase margin of the system.
17
DRV
O
External PNP transistor base drive pin: This pin directly drives the base of an external PNP bipolar
transistor.
18
19
V
I
I
The positive voltage supply pin.
CC
ADJ5
Full charge termination voltage adjust pin: This pin, when grounded will increase the termination voltage
by 15 mV.
20
21
22
23
24
VINOK
G_LED
R_LED
OSC1
OSC2
I
Input voltage overvoltage indicator: This pin is LOW if the input voltage is over the maximum input voltage.
The pin is HIGH when the input voltage is not above the maximum input voltage.
O
O
O
I
Green LED driver pin. This is an open collector output which is connected to a green LED though a series
resistor to limit the current to less than 20 mA to the input voltage.
Red LED driver pin. This is an open collector output which is connected to a red LED though a series resistor
to limit the current to less than 20 mA to the input voltage.
Oscillator out pin: This pin is connected through a timing resistor to the OSC2 pin to set the frequency of the
oscillator and the period of the timers.
Oscillator in pin: This pin is connected through a timing resistor to the OSC1 pin and a timing capacitor to
V
SS
. This sets the frequency of the oscillator and the period of the timers.
4
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
DC ELECTRICAL CHARACTERISTICS
Characteristic of the NE57610Y.
SYMBOL
PARAMETER
Supply current
CONDITIONS
Pin
Min.
Typ.
5.0
Max.
7.0
UNIT
mA
V
I
18
5
–
–
CC
V
REF
Reference voltage
1.207
2.45
100
–
V
ADPL
AC Adaptor detection voltage L
V
V
: H → L
20
20
2.35
50
2.55
150
V
CC
V
AC Adaptor detection voltage L
Hysteresis voltage
mV
ADPL(hys)
V
ADPH
AC Adaptor detection voltage H
: L → H
20
20
6.1
50
6.3
6.5
V
CC
V
AC Adaptor detection voltage H
Hysteresis voltage
100
150
mV
ADPH(hys)
Z
Impedance for AC Adaptor detection
output L
20
–
–
30
–
–
1
kΩ
µA
ADPL
I
BAT pin leakage current
13, 14,
15
BAT
V
V
BAT pin output voltage
DRV pin output voltage
ON/OFF pin input current
ON/OFF pin input voltage H
ON/OFF pin input voltage L
RESET pin input current
RESET pin input voltage H
RESET pin input voltage L
Current limit 1
T
= 0 +50 °C
13
4.070
–
4.100
–
4.130
0.5
V
BAT
amb
I
= 20 mA
17
V
DRV
DRV
ION
1
40
60
–
80
µA
V
/OFF
ON/OFF
ON/OFF
reset
V
V
ON/OFF: OFF
ON/OFF: ON
1
0.6
–
1.20
0.25
80
1
–
V
I
2
40
60
µA
V
V
V
V
V
V
V
V
Charge control circuit: OFF
Charge control circuit: ON
Quick charge
2
0.6
1.20
0.25
0.24
31
reset(high)
2
V
reset(low)
14, 15
14, 15
14, 15
13
0.20
21
0.22
26
V
L1
Current limit 2
Pre-charge
mV
mV
V
L2
Full charge detection
R
I
CS charge
13
18
23
F
Undervoltage voltage detection voltage
V : L → H
BAT
1.90
25
2.00
50
2.10
100
LV
Low voltage detection voltage Hysteresis
voltage
13
mV
LV(hys)
V
V
Pre-charge detection voltage
V : L → H
BAT
13
13
2.80
25
2.90
50
3.00
100
V
P
Pre-charge detection voltage Hysteresis
voltage
mV
P(hys)
V
V
V
Re-charge detection voltage
Overvoltage detection voltage
V
: H → L
BAT
13
13
12
3.85
4.30
0.835
3.90
4.35
0.860
3.95
4.40
0.885
V
V
V
R
V : L → H
BAT
OV
TH
Battery temperature detection voltage H Low temperature 3 °C ± 3 °C
detection
V
TL1
V
TL2
Battery temperature detection voltage L1 High temperature 43 °C ± 3 °C 12
0.390
0.335
0.413
0.353
0.435
0.370
V
V
detection (charging start)
Battery temperature detection voltage L2 High temperature 50 °C ± 3 °C 12
detection (during charging)
IT
TDET input bias current
R_LED pin output voltage
G_LED pin output voltage
Timer error time
12
–
30
–
150
0.4
0.4
10
nA
V
V
LEDR
V
LEDG
ILEDR = 10 mA
ILEDG = 10 mA
22
–
21
–
–
V
∆T
Not including external
deviation (Note 2)
21, 22
–10
–
%
NOTES:
1. Current limits 1 and 2 and full charge detection are specified as current detection resistor voltage drop.
2. Use a capacitor with good temperature characteristics in the oscillator. Capacitor deviation will contribute to timer error.
5
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
TIMING DIAGRAMS
Typical timing for the NE57610Y.
5.5 V
V
CC
0 V
5.5 V
0 V
V
CC
4.1 V
BAT PIN
VOLTAGE
3.9 V
2.9 V
2 V
BAT PIN
4.35 V
VOLTAGE
VOLTAGE AT BAT PIN
OVERVOLTAGE
CHARGING
CURRENT
FOR 0.5 s OR LONGER
CHARGING
CURRENT
0 A
PRE–
CHARGE
SUSTAINING
CHARGE
CHARGING
FULLY
CHARGED
R_LED
R_LED
G_LED
ON
OFF
ON
ON
G_LED
OFF
SL01848
OFF
OFF
SL01847
Figure 3. Normal charging.
Figure 4. Battery overcharge detection.
5.5 V
0 V
5.5 V
0 V
V
CC
V
CC
BATTERY VOLTAGE BATTERY VOLTAGE
NO BATTERY
2.9 V OR MORE
BELOW FULL CHARGE
VOLTAGE CHANGE
BAT PIN
VOLTAGE
2 V OR LESS
14 s
BAT PIN
VOLTAGE
0 V
0 A
4 HOURS
CHARGING
CURRENT
CHARGING
CURRENT
FULL CHARGE
0 A
1 mA CHARGING
R_LED
G_LED
R_LED
G_LED
ON
ON/OFF 0.57 Hz
OFF
ON/OFF0.57 Hz
OFF
SL01849
SL01850
Figure 5. Battery overdischarge detection.
Figure 6. Battery charge time-out.
6
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
TIMING DIAGRAMS (continued)
Typical timing for the NE57610Y.
5.5 V
0 V
5.5 V
0 V
V
V
CC
CC
BATTERY VOLTAGE BATTERY VOLTAGE
2 V OR LESS 2.9 V OR LESS
BAT PIN
VOLTAGE
4.1 V
BAT PIN
VOLTAGE
15 MINUTES
0.11 SECONDS
CHARGING
CURRENT
CHARGING
CURRENT
12% OF
FULL CHARGE
0 A
0 A
ON
OFF
ON
R_LED
G_LED
ON
R_LED
G_LED
ON/OFF0.57 Hz
OFF
OFF
SL01851
SL01852
Figure 7. Conditioning charge failure.
Figure 8. Battery full charge detection.
7 V
5.5 V
V
CC
V
CC
0 V
0 V
3 V
BAT PIN
VOLTAGE
3.9 V
BAT PIN
VOLTAGE
56 ms
CHARGING
CURRENT
FULL CHARGE
0 A
CHARGING
CURRENT
0 A
OFF
ON
ON
R_LED
G_LED
OFF
OFF
R_LED
G_LED
OFF
SL01854
SL01853
Figure 9. Battery topping-off charge.
Figure 10. Supply (adaptor) overvoltage detection.
5 V
V
CC
0 V
3 V
BAT PIN
VOLTAGE
CHARGING
CURRENT
0 A
R_LED
G_LED
OFF
OFF
SL01855
Figure 11. Temperature detection pin open.
7
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
TYPICAL PERFORMANCE CURVES
4.15
4.14
4.13
3.95
3.94
3.93
4.12
3.92
4.11
4.10
4.09
3.91
3.90
3.89
4.08
4.07
4.06
4.05
3.88
3.87
3.86
3.85
–25
0
25
50
(°C)
75
–25
0
25
50
(°C)
75
AMBIENT TEMPERATURE, T
AMBIENT TEMPERATURE, T
amb
amb
SL01856
SL01857
Figure 12. BAT output voltage versus temperature.
Figure 13. Re-charge detection voltage versus temperature.
0.5
0.5
T
amb
= 25 °C
T
amb
= 25 °C
0.4
0.4
0.3
0.2
0.1
0
0.3
0.2
0.1
0
G
R
1
10
100
1
10
LED CURRENT (mA)
100
DRV CURRENT (mA)
SL01858
SL01859
Figure 14. DRV voltage versus DRV current.
Figure 15. LED voltage versus LED current.
8
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
TECHNICAL DISCUSSION
If charging begins with the cell voltage below the overdischarged
Lithium-ion cells: general information
voltage rating of the cell (V ), it is very important to slowly raise the
UV
Lithium-ion and polymer cells have higher voltage than nickel
cadmium (NiCd) or nickel metal hydride (NiMH) rechargeable cells.
The average operating voltage of a lithium-ion or polymer cell is
3.6 V compared to the 1.2 V of NiCd and NiMH cells. The internal
resistances of the various types of lithium cells are 50 mΩ to
300 mΩ, compared to the 5 mΩ to 50 mΩ of the nickel chemistries.
This makes Lithium-ion and polymer cells better for lower battery
current applications, less than 1 ampere, such as cellular and
wireless telephones, palmtop and laptop computers, etc.
cell voltage up to this overdischarged voltage level. This is done with
a reconditioning charge. A small amount of current is allowed into
the cell, and the cell voltage is allowed, for a pre-set period of time,
to rise to the overdischarged voltage (V ). If the cell voltage
UV
recovers, a normal charging sequence can begin as described
above. If the cell does not reach the overdischarged voltage level,
then the cell is considered too damaged to charge and the charge is
discontinued.
It is important to allow enough time to charge the cell to take
advantage of the higher energy density of the lithium cells. When the
charger switches from constant current charge to constant voltage
charge (Point B, Figure 16) the cell only contains about 80 percent
of its full-rated capacity. When the cell is 100 mV less than its full
rated charge voltage, the capacity contained within the cell is about
95 percent. Allowing the cell to slowly complete its charge takes
advantage of the larger capacity of the lithium cells. The complete
charging curve can be seen in Figure 16.
Lithium-ion and polymer cells are safe as long as the cell is
maintained within a particular set of operating boundaries. The cells
have a porous carbon, or graphite anode where individual lithium
ions can lodge themselves within the pores. This keeps the lithium
ions separated, and any hazardous condition is avoided, if the cell is
kept within the safe operating boundaries.
A lithium cell protection circuit is placed within the battery pack. It
monitors the level of voltage across each cell for overcharge and
overdischarge conditions, and the discharge current in the event of
an overcurrent or short-circuit condition. If the lithium cell is
overcharged, pure metallic lithium plates out onto the surface of the
anode. Also volatile gas is generated within the cell. This creates a
1.0
hazard. Conversely, if the cell were allowed to over-discharge (V
cell
less than typically 2.3 V), the chemistry of the cell changes and the
copper metal used in its construction enters the electrolyte solution.
This severely shortens the cycle life of the cell, but presents no
future safety hazard. When the cell experiences high charge or
discharge currents, then the internal series resistance of the cell
creates heating and generation of the volatile gas which could again
present a hazard.
0.5
CONSTANT
CURRENT
CONSTANT
VOLTAGE
1.0
2.0
Charging lithium cells
TIME (HOURS)
An integral part of any Li-ion battery system is a battery charger
specifically designed for the lithium cell being used, with its
particular over and undercharge limits, capacity, etc. The battery
charger should be viewed as a part of the entire lithium battery
system so that safe cell operation can be ensured.
Vov
4.0
Lithium cells must be charged with a dedicated charging controller
such as the NE57610. The charging ICs, in general, can be
Point B
described as performing: a current-limited, constant-voltage charge
process. When the cell is very discharged, the charger IC outputs a
constant current into the battery, which limits the internal heating of
the cells. The maximum charge rate is typically the capacity rating of
the cell. That is, the maximum charge current is the mAHr rating of
the cell(s), that is, a 1000 mAHr cell will be charge with a maximum
of 1000 mA. When the cell voltage approaches its full-charged
3.0
1.0
2.0
voltage rating (V ), the current entering the cell begins to
OV
TIME (HOURS)
SL01554
decrease, and the charger IC provides a constant voltage-mode of
charge. The charge current begins to exponentially decrease over a
long period of time (approximately 1.5 – 2.0 hours). When the
charge current falls below a preset amount, the charge current is
discontinued.
Figure 16. Lithium-ion charging curves.
9
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
2.3V (V ) < V
< 2.9 V (V ): A charge current of approximately
NE57610 OPERATION
UV
batt
P
1
th
/
8
the normal charge current (pre-charge) is placed into the
The typical application schematic is given in Figure 17. Because in
a multiple-cell battery pack, the battery charger cannot access the
connection(s) between the cells within a battery pack, the following
discussion is based upon the calculated value of each cell’s voltage
battery pack. This continues until the cell voltage reaches 2.9 V. If
the pre-charge timer, times out prior to the cell reaching 2.9 V, the
pre-charge is terminated. The charger can be restarted by bringing
RESET momentarily high, or by turning-OFF and then ON the input
voltage.
(V /number of series cells).
batt
Start of charging
The start of the charging process is only permitted when all of the
following conditions are met:
2.9 V (V ) < V
< 4.35 V (V ): The high-rate charge current is
OV
P
batt
placed into the battery pack until the cell reaches a full-charge
condition by either reaching V or V . If the cell does not reach the
OV
F
• The DC input voltage is greater than V
, which indicates there
full-charge level within the period of the charge timer, the charge is
terminated.
ADPH
is sufficient input voltage.
• The battery voltage is less than the overcharged voltage (V
• The reset and ON/OFF pins are both LOW.
V
> 4.35 V (V ) (fully charged): The charge current is
OV
ov)
batt
completely cut off. If the battery pack is allowed to remain on the
charger for an extended period, and if the pack voltage falls to 3.9 V
per cell due to self-discharge, charging begins again at the full rate
of charge until V or V is reached again. This process repeats as
long as the battery is in the charger.
• The battery temperature voltage falls within its recommended
OV
F
operating range.
The charging behavior depends on the voltage of the battery. If the
initial cell voltage is:
Overriding conditions
If, under any of the above conditions, the following conditions are
encountered, the charging process will be immediately terminated.
< 2.0 V (V ) (overdischarged): A 1 mA charge current is sent
into the battery pack and the undervoltage charge timer is set. If the
LV
• If the temperature sensing input is lower than V or higher than
TH
battery pack voltage does not reach 2.3 V (or V ) in this preset
UV
V
TL
voltages. (remember, a thermocouple’s voltage goes down
period of time, the pack is assumed to be damaged and the
charging process is terminated. The charger can be restarted by
bringing RESET momentarily high, or by turning-OFF and then ON
the input voltage.
with higher temperatures)
• If the timer associated with the presently active function times out.
A State diagram of the various modes of the charger can be seen in
Figure 18.
PBYR
240CT
BATTERY PACK
R
V+
CS
BCP51
+V
in
150 Ω
18
17
DRV
15
CS
V
RED
GRN
CC
13
BAT1
BAT2
14
CELL 2
CDLL 1
22
21
3
4
RED
GRN
TP1
TP2
TP1
TP2
10 µF
NE57610
23
5
V
REF
OSC1
R
OSC
24
12
THERM
OSC2
TMP
ON/OFF RESET GND PGND
2
1
6
7
C
T
–V
in
V–
SL01863
Figure 17. Typical application circuit (2-cell).
10
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
1 mA CHARGE
TIMER TIME-OUT
1 mA
CHARGE
RATE
PACK VOLTAGE
> V
UV
PREPARATORY
CHARGE
PACK
PREP
VOLTAGE
TIMER
TIME-OUT
< V
UV
PACK
VOLTAGE
PACK
VOLTAGE
> V
UV
> V
P
CHARGE
AT NORMAL
RATE
V
V
HYSTERESIS
OV
< V – V
pack
OV
OV(hys)
START
CHARGE
PACK VOLTAGE
> V , < V
UV
OV
V
> V
OV
pack
TERMINATE
CHARGE
V
> V
OV
pack
SL01860
Figure 18. State diagram of charging process.
Charge-mode indicators
Programming the total charge timer
Determining which state the battery charger is operating is easily
done by viewing the red and green LEDs which should be wired
between pins 22 and 21, respectively, and the input voltage source.
Each LED should have a 150 Ω resistor in series. Table 1 shows the
states of these LEDs and the two test pins (TP1 (pin3) and TP2
(pin4)).
To set the total charge time, place a timing capacitor (C ) between
T
pin 24 and the ground pins (pins 6 and 7) and a resistor (R
)
OSC
between pins 23 and 24. The typical Li-ion cell requires 3 hours to
totally recharge from V and V so a charge period of greater
UV
OV,
than or equal to 3 hours should be allowed. The total charge time
can be set by referring to Figure 19.
Table 1. Charge mode indicators versus charger activity
OSCILLATOR CAPACITOR
0.01 µF
200 k
100 k
Condition
Pin 22
(Red)
Pin 21
(Green)
Pin 3
TP1
Pin 4
TP2
0.0047 µF
Reconditioning
charge
Blink
OFF
OFF
OFF
Blink
OFF
OFF
Low
Low
Low
Hi Low
Hi Low
Preparatory
charge
ON
0.022 µF
Normal charge
ON
Hi Low
Low
Charge done
OFF
Blink
OFF
1
2
3
4
5
6
Hi Low
Low
CHARGE TIME-OUT (HOURS)
Charge timer
time-out
Low
Low
5
10
15
20
PRECHARGE TIME-OUT (MINUTES)
Fault: V , V
Low
OV LV
V , V
LV IN(min)
5
10
15
20
1 mA TIME-OUT (SECONDS)
SL01864
Figure 19. Total charge time versus C .
T
11
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
Setting the charge currents and detection
thresholds
CS
BAT1
A = 4
The NE57610 has a preset charge termination voltage which is set
during manufacture. The remaining charge currents and detection
thresholds involved during the charging process must be set with
the value of certain resistors and optionally by using the ADJ pins 1
through 4. Setting the thresholds is very important because the
charge termination voltage alone is a state of overcharge for the
lithium cell. If ignored, this can be very hazardous.
V
REF
Figure 16 shows some of the terms and charging periods.
R1
R2
ADJ1
OR
ADJ2
Setting the high-rate charge current
The second most important parameter is the adjustable high-rate
charge current. First, determine the highest rate of charge of the
chosen lithium cell from the cell’s datasheet. This rate must not be
exceeded because it would cause excessive heating of the cell
during charging. The maximum charge rate will typically charge a
completely discharged cell in under 3 hours.
HYST
CS
BAT1
A = 4
Then, calculate the required value of the current sensing resistor
(R ). This resistor also controls the rate of the other charge
CS
currents (pre-charge and reconditioning charge). All of these charge
rates can be individually lowered by adding adjustment resistors to
the ADJ1–ADJ4 pins. (See ‘Using the ADJ1–ADJ4 pins’.)
COMP
The high-rate charging current is set by the value of R and can be
found by the following equation:
CS
V
REF
0.22V
Ichg(high*rate)
R1
R2
RCS
+
Eqn. (1)
ADJ3
OR
ADJ4
The typical value is around 0.3 Ω, which yields a 660 mA for the
high-rate charge. If a current-limited wall transformer is used, this
current may never be reached.
SL01861
The pre-charge rate is set internally at around 1/8th of the high-rate
of charge. This value may also be lowered by adding a resistor to
Figure 20. Equivalent circuits for ADJ1–ADJ4.
V
SS
from the ADJ3 pin. (See ‘Using the ADJ1- ADJ4 pins’.)
Table 2. ADJ1–ADJ4 internal resistor divider values
Using the ADJ1–ADJ5 pins
Using the ADJ1–ADJ5 pins is optional. The NE57610 will operate as
specified when the pins are left unconnected.
Pin
Pin
Pin
voltage
R1
R2
V
OS
name
ADJ1
ADJ2
ADJ3
ADJ4
8
1.16 V
62 mV
120 mV
0.89 V
5.8 kΩ
128 kΩ
146 kΩ
20 kΩ
105 kΩ
10.5 kΩ
16 Ω
–
The ADJ pins are the center-node voltage of an internal resistor
divider which are preset to the values given in the datasheet. Each
of the parameters may be modified by placing an external resistor to
9
4.5 mV
3.1 mV
–
10
11
ground or to V . The ADJx voltages are directly related to the
ref
58 Ω
voltage measured across the current sense resistor (R ) between
CS
CS and the BAT1 & BAT2 pins.
The equation relating the values of ADJ pins to the voltage between
the CS pin and the BAT1 and BAT2 pins is given by Equation (2):
The ADJ5 pin will increase the full-charge voltage (V ) by 15 mV if
the pin is connected to ground.
OV
Eqn. (2)
VADJx + 4(Ix (RCS) ) VOS
)
ADJ1 through ADJ4 are ground-referenced voltages which can
lower the preset values of the overcurrent cutoff (ADJ1), the
top-off-charge minimum current threshold (ADJ2), the pre-charge
charge current (ADJ3), and the high-rate charging current (ADJ4).
The V term is the input offset voltage of the current-sense
OS
amplifier, which varies with the battery voltage. The offset term is
only significant while low levels of current are being sensed, such as
during the pre-charge period and the end-of-charge current
threshold. During the high-rate charge and overcurrent conditions
the contribution of the input offset voltage is negligible.
The overcurrent cutoff current is normally not used because there is
usually a current-limited wall transformer providing the input power
for the charger, and the transformer’s current limit is usually within
the safe range of the cell(s). This cutoff voltage can be lowered by
lowering the ADJ1 voltage.
The equivalent circuits for the ADJ1–ADJ4 circuits are shown in
Figure 20.
12
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
Adjusting current levels with ADJ1–ADJ4
First, calculate the desired voltage of the ADJ pin in question. This is
done by executing Equation (2), and using the value of the input
2
offset voltage (V ) if applicable. It becomes a matter of solving a
OS
D2PAK (SOT404)
resistor divider problem with a parallel resistor on the lower branch.
The equation becomes (referring to the resistor designators in
Figure 16 and the values from Table 2):
ǒ
Ǔ
VADJx(R1R2)
VREF R2 * VADJx (R1 ) R2)
where R is the external resistor from the respective ADJ pin to
DPAK (SOT428)
Eqn. (3)
Rext
+
1
ǒ
Ǔ
ext
V
SS
.
SOT223 (SC-73)
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:
SOT23 (SST3)
50
25
75
100
MAXIMUM AMBIENT TEMPERATURE (°C)
• 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 1.6 V which would make the minimum input
voltage about 5.6 V. This requirement also includes the troughs of
any ripple voltage riding atop the DC input voltage from a poorly
filtered wall transformer.
SL01865
Figure 21. Maximum power dissipation versus ambient
temperature versus package.
This chart gives the package to use the minimum recommended pad
size is used under the power part. Making the pad size larger can
increase the power handling capacity of the part without sacrificing
its reliability. Table 3 shows how to dissipate more power in a
smaller package.
• The maximum input voltage must not exceed the voltage ratings
of the components contained within the charging circuit.
• The power rating and the thermal design of the linear pass
transistor must be able to withstand the maximum experienced
headroom voltage at the high-rate charge current. The worst case
condition can be calculated by assuming the cell is at its lowest
typical voltage (2.9 V) and the input voltage is at its highest point
in its range (typically the DC voltage created at the highest AC
input) times the high-rate charge current. The power can then be
calculated by Equation (4):
Table 3.
Pad size
2X
R
Power increase
th(j–a)
0.88 °C/W
0.80 °C/W
0.74 °C/W
0.70 °C/W
14%
25%
35%
43%
3X
4X
ǒ
Ǔ ǒ
Ǔ
Eqn. (4)
P
D(max) + Vin(max) * Vcell(min) Icharge
5X
The criteria for the selection of the PNP power transistor should be:
NOTES:
V
CEO
>
1.5 V
in(max)
1. Going beyond five times the minimum recommended footprint
yields diminishing improvements to the thermal performance.
2. Given for an F4 fiberglass PCB with 2 oz. copper
I
> 1.5 I
charge
C
h
> 50 @ 1 Amp
FE
P
D
> P
D(max)
The choice of power transistor package should be done with the
highest possible power dissipation and at the highest expected
ambient temperature. Choose a surface mount package by referring
to Figure 21 and drawing two intersecting lines from the appropriate
points on the X and Y axis.
13
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
dealt with by examining how the circuit powers-up and making sure
there are no power-up sequences that can lead to a component
failure or hazardous operating conditions.
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.
A common adverse operating condition at the input is
lightning-caused transients. A simple 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 entering the zener diode
and will distribute the energy over a longer period.
Some of the user-related issues are: plugging the battery pack into
the charger backwards, inserting of the battery into the live charger,
and plugging the charger into an unexpected input voltage source.
A series diode is typically used for reversed battery protection. This
prevents reverse currents from flowing into the device, protecting
the functionality of the charger. Protecting against live insertion of
the battery and the wrong type of input power to the charger must be
PACKING METHOD
The NE57610 is packed in reels, as shown in Figure 22.
GUARD
BAND
TAPE
TAPE DETAIL
REEL
ASSEMBLY
COVER TAPE
CARRIER TAPE
BARCODE
LABEL
BOX
SL01305
Figure 22. Tape and reel packing method
14
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
TSOP-24: plastic thin shrink small outline package; 24 leads; body width 4.4 mm
0.2
0.1
0.25
0.1
6.8
6.37
6.7
6.1
0.8
0.2
10°
0°
0.5
15
2002 Nov 05
Philips Semiconductors
Product data
Li-ion battery charger control
with adjustable thresholds
NE57610
REVISION HISTORY
Rev
Date
Description
_1
20021105
Product data; initial version.
Engineering Change Notice 853–2351 28505 (date: 20020620).
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. 2002
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: 11-02
9397 750 10465
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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