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BA3170 型埋离子电池泪流充电器 IC 及其应用
山东省临沂市计算机公司
张润领
北京智千里科贸有限公司
澜翩翩匾
司
,..
巾
摘
要:本文介绍了 2 节捏离子电池涓流充电器 BA3170 单片 IC 的功能、特点及其应用 O
关键词:捏离子电池
涓流充电器 BA3170
BA3170 是 2 节铿离子电池涓流充电器 IC ，其内
部结构主要包含充电控制电路、充电输出晶体管和
表 1
脚号
'J I 脚名利;
显示充电状态的 LED 驱动器等。
、 BA3170 的引脚功能及其主要特点
BA3170 引脚名称及功能
功
仁I
脉冲充电频率设定
?
CP
与地之间连接 4 只电容，以阻止振荡
3
。 CP
输出电流限制设定
BA3170 的内部结构及其应用电路如图 l 所
4
1\ .C
未连接
5
OLT
输出
BA3170 采用 12 脚 HSIP - B12 单列直插式小型
6
封装，可提供较大的功率耗散。 BA3170 的各引脚名
7
GLED
充电完成 LED 输出
称及功能如表 1 所列 O
8
RLED
充电 LED 输出
BA3170 涓流充电器 IC 的主要特点如下:
9
5TB
待机
1.输出电压可以通过外部电阻调整;
10
\rlU f
充也终止电压输出
11
I ref
充电终11::电压设定
12
G\D
刁 '0
2. 用低饱和压降的 PNP 晶体管输出;
zeι
SE.
,
能
电源
旦，
地
OUT
δUT
脉 ~I' 先电
F
王切问 99
电 i也核验
I负检测
调节器
5
3
币附
T J10μF
T71
因
BA3170 充电器 IC 的内部电路阁
29
BA3170 型但离子也也确坡，充电忌 IC 及其雇用
3. 内建输出电流限制电路，以防止电地过电流，
(>)
并防止因输出短路而使 IC 损坏;
1
4. 在满电压 99% 的情况下进行脉冲充电;
5. 内建过放电电池回复电路;
6. 内置充电故障保护电路;
J
7. 内建过电压电池操作电路;
iE
"二
5
Q
8. 内建两路输出 LED 充电显示电器;
fj
f叫
11
。
> 10
tE
w
....J
9. 内建温度保护电路，以防止 IC 因温度过高Tfrî
o
损坏。
50
100
充电 rt! 流
二、主要技术参数
图 2b
10
150
(mA)
200
充电电流与充电终止 LED 输出电压关系曲线
1.极限参数
BA3170 的极限参数见表 20
表 2
..111 脚
BA3170 的极限参数 (Ta
= 25 't:)
Vcc
23
V
功率耗散
Pd
2200
mW
工作温度
Topr
- 30 -
储存温度
Tslg
输出电流
10
- 55 - + 150
400
mA
LED 输出电流
lLO
200
mA
LED 输出电压
VLO
Vcc
V
备用电压
VSTB
Vcc
V
+ 85
电
气:
μ
汀川
施加电压
脉冲充电从 8 .4VXO.99 i'J8.4V
ιA
单位
电
限制值
崎恻
符号
参数名称
输，'jll 且 ùfL
主!色 LED
。N.
厂， nfl
"色 LED
。FF ‘
图 2c
BA3170 相关波形图
2. 主要电气特性
BA3170 的电源电压推荐值为 10 - 20V; 电路电
流为 0.8mA ，输出电路初始充电电流为 100mA ，充电
三、应用指南
电 i成为 300 :t 100mA ，充电终结电流为 85 :t 30mA; 充
电开始输出电压为 2.5 :t
O. 2V ，充电电流开关电压为
根据图 l 所示的应用电路框图，有关应用事项如 F
下:
6.4 :t o. 3V; 脉冲充电开始电压为 8.316V( 典型值) ,
1.充电终止电压的设定。在图 l 中，连结于脚
脉冲充电频率为1. 54kHz( 典型值) ;基准电压为
10 与脚 11 、脚 11 与脚 12 之间的电阻 RI 和凡的数
1. 22V (典型值) ;LED 输出电压为( Vcc - I) v ，输出峰
值，设定终止电压比ufo 在图 3(a) 所示的电路中，若
值电流最大值是 50μA;
设定比 uf= 8. 4V , r 列等式成立:
输入待机电压最大值为
O. 8V ，输入有源电压最小值是 2V ，输人高电平电流为
175μA( 典型值)。
3
•
1. 22= R1/(RI + R2) x8.4
电特性曲线
BA3170 的典型特性曲线及相关波形如图 2 所
ï]三
12
~
10
>
>
。
-"'
g
e
~
Vbuf
R,
Vref
,
8
6
4
』卢-
O
V∞=12V
Ta=2TC
2
100
Set for 300mA
200 300 400
元屯电流
图 2a
30
10 CmA)
充电电压与充电电流关系曲线
凶 3a
终止电压由 Rl 和 R2 设定
若取 R 2 二 IOkD ，那么 ， RI =58. 7H1c,
2. 输出电流限制。在图 3(b) 所示的电路中，通
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4于发应用、嘲
3. 输出电容 CI ，宜采用静态容差不大于:t
10%
的钮电容，且容值随温度变化要小;定时电容 CT 采
用薄膜电容，容差不大小土 10% ，在允许的工作温度
范围内，容量变化不超过额定值的:t 2% 。
4. 尽管 BA3170 含有过电流限制、过电压保护
和热关闭等保护电路，但为避免 IC 损坏，应注意 IC
不能超过安全工作区 (SOA) 工作。
5. 为正确应用 BA3170 ，图 4 给出了测量电路，
图 3b
以供参考 O
输出电流限制电路
过品和 R4 设定输出脚 OCP 上的电压，有关数据如
表 3 所列。
表 3
比与 R. 不同取值对应的输出电流和 OCP 电压
输出电流
R3
R,
200mA
56kO
20kO
300mA
56kO
43kO
表 3 列出的数据是在 Ta = 25 "C、 Vcc = 12V 、
图 4
内uf= 8. 4V 和 Vo=7.4V 条件下给出的。
测量电路
,
,
,
Regulator ICs
Trickle-charge IC for two-cell,
lithium-ion batteries
BA3170
The BA3170 is a trickle-charge IC developed for two-cell, lithium-ion batteries.The IC includes a charge control circuit,
a charge output transistor, and an LED driver for showing the charging status.
Applications
Lithium-ion (two cell) battery chargers, and charging circuits
Features
1) Output voltage can be varied using an external resistor.
2) The output pin is PNP output with low saturation voltage.
3) Built-in output current limiting circuit protects batteries from excessive current, and prevents destruction
of the IC due to output shorts.
The initial charge current is set to a low value (the current limit pin voltage can be used to vary the current
limit value).
4) Pulse charging at over 99% of the final voltage.
5)
6)
7)
8)
9)
Built-in over-discharge battery return circuit.
Built-in charge fault protection circuit.
Built-in over-voltage battery operation circuit.
Built-in LED output for charge display (two outputs).
12-pin power package provides large power dissipation in a compact package.
10) Temperature protection circuit prevents thermal destruction of the IC.
Absolute maximum ratings (Ta = 25C)
Recommended operating conditions (Ta = 25C)
395
Regulator ICs
Block diagram
396
BA3170
Regulator ICs
BA3170
Pin descriptions
Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 12V, R1 = 58.7kΩ, R2 = 10kΩ)
397
Regulator ICs
BA3170
Operation notes
(1) Do not use values other than CT = 0.022µF for the timing capacitor, and C1 = 10µF for the output capacitor.
(2) For the output capacitor C1, use a tantalum capacitor with low capacitance variation with temperature, and a static
capacitance tolerance of ±10% or less.
(3) For the timing capacitor CT, use a film capacitor with low capacitance variation with temperature, a static capacitance tolerance of ±10% or less, and a temperature variation rate of ±2% or less.
Measurement circuit
Fig.1
398
Regulator ICs
BA3170
Timing chart
Fig.2
External components
Setting the “end point voltage”
Set the “end point voltage” Vbuf using resistors R1 and
R2.
Example:
To set Vbuf to 8.4V:
1.22 = R2 / (R1 R2) 8.4
R1 = 5.88 . . . R2
If R2 = 10kΩ, then
R1 = 58.7kΩ
∗ For measurement of the electrical characteristics, Vref and Vbuf are
shorted.
Fig.3
399
Regulator ICs
BA3170
FReference data
S Output current limit value
Set the value for the OCP voltage using R3 and R4(Ta =
25_C, VCC = 12V, Vbuf = 8.4V, and Vo = 7.4V (Typ.))
Fig.4
S Charging current and charge complete current for when the “end point voltage” is set to 8.4V ±50mV (Ta = 25_C and
VCC = 12V)
S Charge “end point voltage” temperature characteristic (VCC = 12V, R1 = 58.7kΩ, R2 = 10kΩ, and CT = 2.2V)
FOperation notes
(1) Application circuit (in the block diagram)
We guarantee the application circuit design, but recommend that you thoroughly check its characteristics in actual use.
If you change any of the external component values,
check both the static and transient characteristics of the
circuit, and allow sufficient margin in your selections to
take into account variations in the components and ICs.
Note that Rohm has not fully investigated patent rights
regarding this product.
400
(2) Operating voltage range
Provided that the IC is operated within the recommended
operating voltage range, the operation of the circuit is
guaranteed within the allowed operating temperature
range.
With regard to the values for the characteristics, the rating values for electrical characteristics cannot be guaranteed, but within these ranges there will not be a dramatic
change in the values for the characteristics.
(3) Notes regarding power dissipation (Pd)
A derating characteristic is provided for power dissipation. Your design should not require the component to
dissipate more than its maximum allowed power dissipation over the operating temperature range.
Regulator ICs
(4) Over-voltage protection circuit
When the voltage between VCC (pin 6) and GND (pin 12)
exceeds about 27V (at normal temperature), the overvoltage protection circuit switches all outputs off.
Make sure to use the IC within this voltage limit.
(5) Capacitors to prevent oscillation of the outputs
Be certain to connect capacitors between OUT (pin 5)
and ground, and CP (pin 2) and ground to prevent oscillation. We recommend tantalum capacitors that have low
capacitance variation with temperature (particularly for
the OUT pin).
(6) Thermal shutdown circuit
A thermal shutdown circuit is provided on the IC to prevent it from being destroyed by high temperatures. When
this circuit operates, all outputs go off, and when the temperature drops to a certain level, operation resumes.
(7) Output circuit construction
The outputs use PNP power transistors. When the VCC
(pin 6) voltage drops, even if the external capacitor on the
output side causes the output-side voltage to exceed the
VCC-side voltage, the IC will not be destroyed.
BA3170
(8) Grounding
With regard to the ground connections shown in the application example circuit, make the PCB connections
from each earth to the GND pin (pin 12) reasonably short,
and design your pattern layout to avoid electrical interference between the pattern lines.
(9) ASO
This IC includes a variety of protection circuits, but depending on the operation conditions, it may be possible
to exceed the ASO.
Exceeding the ASO will result in destruction of the IC, so
take due care to ensure that the ASO conditions are never exceeded.
(10) Great care has been paid to the quality of this component. However, due to the nature of lithium-ion batteries, if there is a risk of danger due to failure of this component (e.g. fire or explosion), be certain to take appropriate
measures in your design (fuses etc.).
Electrical characteristics curves
401
Regulator ICs
External dimensions (Units: mm)
402
BA3170