AT1457M-GRE [GMT]
Power Management Circuit,;![AT1457M-GRE](http://pdffile.icpdf.com/pdf2/p00284/img/icpdf/AT1457AM-GRE_1690781_icpdf.jpg)
型号: | AT1457M-GRE |
厂家: | ![]() |
描述: | Power Management Circuit, |
文件: | 总12页 (文件大小:287K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Features
General Description
• Ideal for Single-Cell (4.1 V or 4.2 V) and Li-Ion The AT1457 series Lithium-Ion (Li-Ion) and
or Li-Pol Packs
Lithium-Polymer (Li-Pol) linear charge ICs are
designed for cost-sensitive and compact portable
electronics. They combine high-accuracy current
and voltage regulation, battery conditioning,
temperature monitoring, charge termination, and
charge-status indication in a single 8-pin IC.
MSOP package options are offered to fit a wide
range of end applications.
• Better Than ±1% Voltage Regulation Accuracy
With Preset Voltages
• Optional Cell-Temperature Monitoring Before
and During Charge
• Integrated Voltage and Current Regulation With
Programmable Charge-Current and High or
Low-Side Current Sensing
• Charge Status Output for Single or Dual Led or
Host Processor Interface
The AT1457 continuously measures battery
temperature using an external thermistor. For
safety, the AT1457 inhibits charge until the battery
temperature is within user-defined thresholds.
• Automatic Battery-Recharge Feature
• Charge Termination by Minimum Current
• Automatic Low-Power Sleep Mode When VCC
is Removed
The AT1457 then charges the battery in three
phases: conditioning, constant current, and
constant voltage. If the battery voltage is below the
low-voltage threshold, V(min), the AT1457
precharges using a low current to condition the
battery. The conditioning charge rate is
approximately 10% of the regulation current. After
conditioning, the AT1457 applies a constant
current to the battery. An external sense-resistor
sets the current. The sense-resistor can be on either
the high or low side of the battery without
additional components. The constant-current phase
continues until the battery reaches the charge-
regulation voltage. The AT1457 then begins the
constant-voltage phase. The accuracy of the
voltage regulation is better than ±1% over the
operating- temperature and supply-voltage ranges.
For single cells, the AT1457 is offered in two
fixed-voltage versions: 4.1 V, and 4.2 V. Charge
stops when the current tapers to the charge
termination threshold, I(TERM). The AT1457
automatically restarts the charge if the battery
voltage falls below the V(RCH) threshold.
•Requires Small Number of External Components
• Packaging: 8-Pin MSOP
Applications
•1-Cell Lithium-Ion And Lithium-Polymer
Charger
• DSC
Aimtron reserves the right without notice to change this circuitry and
specifications.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
1
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Block Diagram
Pin Configuration
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
2
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Ordering Information
Part number
AT1457M
Package
MSOP8(4.2V version)
Marking
1457
AT1457M_GRE MSOP8(4.2V version),Green
1457, date code with one bottom line
1457A
AT1457AM
MSOP8(4.1V version)
AT1457AM_GRE MSOP8(4.1V version),Green
1457A, date code with one bottom line
Pin Description
Pin No. Symbol
I/O
I
I
O
—
O
I
I
I
Description
1
2
3
4
5
6
7
8
VCC
Supply voltage
TS
Temperature sense input
Charge status output
Ground
STAT
VSS
CC
VCC1
SNS
BAT
Charge control output
Supply voltage
Current sense input
Voltage sense input
Absolute Maximum Ratings
Parameter
Power supply voltage
Input voltage
Symbol
Condition
Rated Value
Unit
Min.
-0.3
-0.3
-0.3
-0.3
—
—
—
—
Max.
VCC
V(BAT)
V(SNS)
—
—
—
—
+8
VCC+0.3
VCC+0.3
V
V
V
VCC+0.3
20
V(TS)
V
Sink current (STAT pin)
Source current (STAT pin)
Output current (CC pin)
Total power dissipation
Operating free-air temperature range
Storage temperature range
Lead temperature
IOL
not to exceed PD
not to exceed PD
not to exceed PD
at 25℃
mA
mA
mA
mW
℃
IOH
10
IO(CC)
PD
40
300
-20
-40
-
-
TA
Tstg
TL
+85
+125
300
-
℃
℃
soldering, 10 s
Recommended Operating Conditions
Parameter
Symbol
Values
Typ.
-
Unit
Min.
4.5
-20
Max.
7
+85
Power supply voltage
Operating free-air temperature range
VCC
TA
V
°C
-
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
3
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Electrical Characteristics
(VIN=4.5V to 7V, T =-20°C to +85°C unless otherwise noted. Typical value are at T =+25°C)
A
A
Parameter
Symbol
Condition
Values
Min. Typ. Max.
Unit
V
CC > VCC(min),
VCC Current
VCC Sleep current
I(VCC)
--
2
4
mA
Excluding external
loads
V
(BAT) ≥ V(min)
,
I(VCCS)
--
--
3
6
1
µA
µA
V(BAT) - VCC ≥0.8V
Entire device
Input bias current on
BAT pin
IIB(BAT) V(BAT) = V(REG)
--
Input bias current on
IIB(SNS) V(SNS) = 5 V
IIB(TS) V(TS) = 5 V
--
--
--
--
5
5
µA
µA
SNS pin
Input bias current on
TS pin
4.059 4.10 4.141
4.158 4.20 4.242
V
V
Battery Voltage
Regulation
Output voltage
VO(REG)
--
High-side current
95.4 105 115.5 mV
sensing configuration
Low-side current
Current regulation
threshold
Current Regulation
V(SNS)
100 110 121 mV
sensing configuration
Voltage at pin SNS,
relative to VCC for high-
side sensing, and to Vss
for low-side sensing, 0
Charge termination
current detect
threshold
Charge Termination
Detection
V(TERM)
4
14
24 mV
℃≤TA≤50℃
Lower temperature
threshold
V(TS1)
V(TS2)
V(min)
29.1 30 30.9 %Vcc
Temperature
Comparator
TS pin voltage
Upper temperature
threshold
%Vcc
58.3 60 61.8
2.94 3.06
3.04 3.1 3.16
3
V
V
Precharge
Precharge threshold
--
Comparator
Voltage at pin SNS,
relative to VCC for high-
side sensing, and to VSS
for low-side sensing, 0
--
3
13
13
--
mV
Precharge current
regulation
Precharge current
regulation
℃≤TA≤50℃
V( PRECHG)
Voltage at pin SNS,
relative to VCC for high-
side sensing,
22 mV
0℃≤TA≤50℃, VCC=5V
VRCH Comparator
(Battery Recharge
Threshold)
VO(REG) VO(REG)
Recharge
threshold
VO(REG)
-98mV
-
-
V(RCH)
--
V
100mV 102mV
Output (low) voltage
Output (high) voltage
VOL(STAT) IOL = 10 mA
VIOH = 5 mA
--
VCC-
0.5
--
--
0.7
--
V
V
STAT PIN
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
4
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Output low voltage
Sink current
VOL(CC) IO(CC) = 5 mA (sink)
--
5
--
--
1.5
V
CC PIN
Not to exceed power
IO(CC)
40 mA
rating specification (PD)
Figure 1: Typical Charge Profile
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
5
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Figure 2: AT1457 Operational Flow Chart
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
6
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Typical Application Circuit
Figure 3: 0.5A Charger Using P-Channel MOSFET
Figure 4: 0.5A Charger Using PNP Transistor
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
7
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Figure 5: 0.5A/0.1A Charger Using P-Channel MOSFET Switching
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
8
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Application Information
1. Charge Current Formula:
Precharge Current:
VPRECHG
RSNS
IPRECHG
=
Current Regulation Charging :
VSNS
RSNS
ICHG
=
Charge Termination Current:
VTERM
IT =
RSNS
2. High-Side And Low-Side Current Sensing
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
9
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
3. Battery Temperature Monitor
The AT1457 continuously monitors temperature by measuring the voltage between
the TS and VSS pins. A negative or a positive temperature coefficient thermistor
(NTC or PTC) and external voltage divider typically develop this voltage. The
AT1457 compares this voltage against its internal V
and V threshold to
TS1
TS2
determine if charging is allowed.
The resistor value of RT1 and RT2 ars calculated by the following equations:
For NTC Thermistor
5× RTH × RTC
RT1 =
3× (RTC − RTH )
5× RTH × RTC
RT 2
=
[(
2 × RTC
− 7 × RTH
) ( )]
For PTC Thermistor
5× RTH × RTC
3× (RTH − RTC )
5× RTH × RTC
RT1 =
RT 2
=
[
(
2 × RTH
is the cold temperature resistance and R
)
−
7 × RTC
( )]
R
is the hot temperature resistance of
TH
TC
thermistor.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
10
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
4.Reverse Current Blocking Diode
(A) Transistor Circuit Application
When using the AT1457 with a PNP Transistor, a reverse-blocking diode is not
required because there is no current path from BAT to VIN. However, it is
advisable to still place a diode to the circuit. In the event where the input supply is
interrupted or removed during the constant current or constant voltage phases, the
battery under charge will discharge through the circuit pass transistor rendering it
impossible to turn off. If the circuit is unable to turn off, the reverse leakage will
discharge the battery. A Blocking diode will prevent this undesirable effect.
(B) MOSFET Circuit Application
An reverse blocking diode is required for the circuit show in Figure 3. The blocking
diode gives the system protection from a shorted input. It also prevent the leakage
current of battery when the input power is interrupted or removed.
5.Input Capacitor
It is good design practice to place a decoupling capacitor between VCC and VSS
pins. An input capacitor in the range of 0.1µF to 10µF is recommended. A larger
input capacitor in application will minimize switching or power bounce effects
when the power supply is “hot plugged” in.
6.Input Capacitor
The AT1457 does not need an output capacitor for stability of the device itself,
However, a capacitor connected between BAT and VSS will control the output
voltage when the AT1457 is powered up when no battery is connected. If a high
impedance load is placed across the BAT pin to VSS, the AT1457 can become
unstable. Such a case is possible with aging Li-Ion battery cells. As cells age
through repeated charge and discharge cycles, the internal impedance can rise over
time. A 10µF or larger output capacitor will compensate for the adverse effects of a
high impedance load and assure device stability over all operating conditions.
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
11
AT1457
Preliminary Product Information
1-Cell Lithium-Ion And Lithium-Polymer
Charge Management IC
Package Outlines (units:mm): MSOP-8
INCHES
MILLIMETERS
SYMBOL
NOTES
MIN
MAX
MIN
MAX
A
A1
B
0.037
0.002
0.010
0.005
0.116
0.043
0.006
0.014
0.007
0.120
0.94
0.05
0.25
0.13
2.95
1.10
0.15
0.36
0.18
3.05
-
-
-
-
-
-
-
C
D
e
0.0256 BSC
0.65 BSC
E
0.116
0.120
0.198
0.026
6°
2.95
4.78
0.41
0°
3.05
5.03
0.66
6°
H
L
0.188
0.016
0°
-
-
α
S
0.207 BSC
0.525 BSC
2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: 886-3-563-0878
Fax: 886-3-563-0879
WWW: http://www.aimtron.com.tw
Email: service@aimtron.com.tw
12
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