参数资料
| 型号： | LT1769CGN |
| 厂商： | Linear Technology |
| 文件页数： | 12/16页 |
| 文件大小： | 0K |
| 描述： | IC BATT CHARGER CONST I/V 28SSOP |
| 标准包装： | 49 |
| 功能： | 充电管理 |
| 电池化学： | 铅酸，锂离子，镍镉，镍氢 |
| 电源电压： | 8 V ~ 25 V |
| 工作温度： | 0°C ~ 70°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-SSOP（0.154"，3.90mm 宽） |
| 供应商设备封装： | 28-SSOP |
| 包装： | 管件 |
| 产品目录页面： | 1340 (CN2011-ZH PDF) |
LT1769
APPLICATIO N S I N FOR M ATIO N
charger may be turned on periodically to complete a short
float-voltage cycle.
Current trip level is determined by the battery voltage, R1
through R3 and the sense resistor (R S1 ). D2 generates
hysteresis in the trip level to avoid multiple comparator
transitions.
Nickel-Cadmium and Nickel-Metal-Hydride Charging
The 2A Lithium-Ion Battery Charger shown in Figure 1 can
be modified to charge NiCd or NiMH batteries. For ex-
ample, if a 2-level charge is needed; 1A when Q1 is on and
100mA when Q1 is off.
LT1769
PROG
is not nearly as pronounced. This makes it more difficult
to use – dV/dt as an indicator of full charge, and an
increase in battery temperature is more often used with a
temperature sensor in the battery pack. Secondly, con-
stant trickle charge may not be recommended. Instead, a
moderate level of current is used on a pulse basis ( ≈ 1%
to 5% duty cycle) with the time-averaged value substitut-
ing for a constant low trickle. Please contact the Linear
Technology Applications department about charge termi-
nation circuits.
If overvoltage protection is needed, R3 and R4 can be cal-
culated according to the procedure described in Lithium-
Ion Charging section. The OVP pin should be grounded if
not used.
When a microprocessor DAC output is used to control
charge current, it must be capable of sinking current at a
300 ?
1 μ F
R1
49.3k
Q1
R2
5.49k
compliance up to 2.5V if connected directly to the PROG pin.
Thermal Calculations
[ 7.5mA + ( 0.012 )( I BAT ) ]
( V BAT ) 2
( I BAT )( V BAT ) 2 ? 1 + V BAT ?
55 ( V IN )
( I BAT ) ( 2 R SW BAT ) + t V I f
( OL IN BAT )( )
)( )(
)( V
P SW =
V
1769 F05
Figure 6. 2-Level Charging
For 1A full current, the current sense resistor (R S1 ) should
be increased to 0.1 ? so that enough signal (10mV) will be
across R S1 at 0.1A trickle charge to keep charging current
accurate.
For a 2-level charger, R1 and R2 are found from:
R1 = ( 2.465 )( 2000 ) R2 = ( 2.465 )( 2000 )
I LOW I HI ? I LOW
All battery chargers with fast charge rates require some
means to detect full charge in the battery and terminate the
high charge current. NiCd batteries are typically charged at
high current until a temperature rise or battery voltage
decrease is detected as an indication of near full charge.
The charging current is then reduced to a much lower
value and maintained as a constant trickle charge. An
intermediate “top off” current may also be used for a fixed
time period to reduce total charge time.
NiMH batteries are similar in chemistry to NiCd but have
two differences related to charging. First, the inflection
characteristic in battery voltage as full charge is approached
If the LT1769 is used for charging currents above 1A, a
thermal calculation should be done to ensure that junction
temperature will not exceed 125 ° C. Power dissipation in
the IC is caused by bias and driver current, switch resis-
tance and switch transition losses. The GN package, with
a thermal resistance of 35 ° C/W, can provide a full 2A
charging current in many situations. A graph is shown in
the Typical Performance Characteristics section.
P BIAS = ( 3.5mA )( V IN ) + 1.5mA ( V BAT )
+
V IN
P DRIVER =
IN
R SW = Switch ON resistance ≈ 0.16 ?
t OL = Effective switch overlap time ≈ 10ns
f = 200kHz
1769fa
12
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相关代理商/技术参数 |
参数描述 |
|---|---|
| LT1769CGN#PBF | 功能描述:IC BATT CHARGER CONST I/V 28SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 其它有关文件:STC3100 View All Specifications 特色产品:STC3100 - Battery Monitor IC 标准包装:4,000 系列:- 功能:燃料，电量检测计/监控器 电池化学:锂离子（Li-Ion） 电源电压:2.7 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-MiniSO 包装:带卷 (TR) 其它名称:497-10526-2 |
| LT1769CGN#TR | 功能描述:IC CHARGER BATT CONST V/I 28SSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR) |
| LT1769CGN#TRPBF | 功能描述:IC BATT CHARGER CONST I/V 28SSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR) |
| LT1769IFE | 功能描述:IC BATT CHRGR CNSTNT I/V 20TSSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR) |
| LT1769IFE#PBF | 功能描述:IC BATT CHRGR CNSTNT I/V 20TSSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 电池管理 系列:- 产品培训模块:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 标准包装:2,500 系列:- 功能:电池监控器 电池化学:碱性，锂离子，镍镉，镍金属氢化物 电源电压:1 V ~ 5.5 V 工作温度:-40°C ~ 85°C 安装类型:表面贴装 封装/外壳:SOT-23-6 供应商设备封装:SOT-6 包装:带卷 (TR) |
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