- 您现在的位置：买卖IC网 > PDF目录16238 > MAX1538ETI+ (Maxim Integrated Products)IC PWR SOURCE SELECTOR 28-TQFN PDF资料下载
参数资料
| 型号： | MAX1538ETI+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 15/22页 |
| 文件大小： | 0K |
| 描述： | IC PWR SOURCE SELECTOR 28-TQFN |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 60 |
| 功能： | 双电池控制器 |
| 电池化学： | 所有电池类型 |
| 电源电压： | 4.75 V ~ 28 V |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-WFQFN 裸露焊盘 |
| 供应商设备封装： | 28-TQFN-EP（5x5） |
| 包装： | 托盘 |
Power-Source Selector for
Dual-Battery Systems
not allowed until the battery is removed or the charge
ADAPTER
ADAPTER
ADAPTER
path to the battery is selected. Battery removal is
detected when V BAT_ falls below 2V. For correct detec-
tion of battery removal, ensure that the leakage current
ADAPTER
SWITCH
SYSTEM
ADAPTER
SWITCH
SYSTEM
ADAPTER
SWITCH
SYSTEM
into BAT_ is lower than the leakage current out of BAT_
so that BAT_ falls below 2V when the battery is
removed. The contributors to leakage current into BAT_
are D1, D2, P6, and P7.
BATTERY
BATTERY
BATTERY
CHARGER
SWITCH
CHARGER
SWITCH
CHARGER
SWITCH
Battery Relearn Mode
The MAX1538 implements a battery relearn mode,
"A"
SWITCH
"B" "A"
SWITCH SWITCH
"B" "A"
SWITCH SWITCH
"B"
SWITCH
which allows for host-device manufacturers to imple-
ment a mode for coulomb-counting fuel gauges (such
as the MAX1781) to measure battery capacity without
user intervention. In battery relearn mode, the AC
adapter is switched off and battery discharge is select-
ed. In this implementation, the host system could
CHARGE
DISCHARGE/
RELEARN
AC/AIR
prompt users when their battery capacity becomes
inaccurate, use the host system as a load to discharge
the battery, and then recharge the battery fully.
Figure 4. MAX1538 Selection States
Battery Presence and
Undervoltage Detection
The MAX1538 determines battery absence and under-
voltage and does not allow discharge from an under-
voltage battery. A battery is considered undervoltage
when V BAT_ < 5 x V MINV_ , and remains classified as
undervoltage until V BAT_ falls below 2V and again rises
above 5 x V MINV . The undervoltage latch is also
cleared when the charge path is enabled. Set the bat-
tery undervoltage threshold using resistive voltage-
dividers R10, R11, R12, and R13, as shown in Figure 1.
The corresponding undervoltage threshold is:
Coulomb-counting fuel-gauge accuracy is increased
after a relearning cycle.
Battery relearn mode requires the addition of MOSFET
P1, which blocks current from the adapter to the sys-
tem. To enable relearn mode, drive RELRN high and
drive BATSEL low to relearn battery A or high to relearn
battery B. Relearn mode overrides the functionality of
the CHG pin. Battery relearn mode does not occur
when the selected battery ’s undervoltage latch has
been set, or when the selector is in airline mode (see
the Airline Mode and AC Adapter section . ) The RELRN
pin only applies when an AC adapter is present. If the
AC adapter is absent and RELRN is ignored, OUT[2:1]
= 10 when the MAX1538 is in battery relearn mode. If
V BATA _ Undervoltage = 5 × V DD ×
V BATB _ Undervoltage = 5 × V DD ×
R 11
R 10 + R 11
R 13
R 12 + R 13
CHG = 0, only OUT2 is needed to indicate that the
MAX1538 was properly placed in relearn mode.
If the selected battery trips the undervoltage latch when
in relearn mode, the AC adapter is switched in without
causing a crash to the system. OUT2 can indicate that
the relearn cycle is terminated due to battery undervolt-
age. Typically, after the host system performs a battery
relearn cycle, it either charges the discharged battery
To minimize error, use 1% or better accuracy divider
resistors, and ensure that the impedance of the divider
results in a current about 100 times the MINV_ input
bias current at the MINV_ threshold voltage. To opti-
mize error due to 50nA input bias current at MINV_ and
minimize current consumption, typically choose resis-
tors (R10 + R11) or (R12 + R13) smaller than 600k ? .
Since batteries often exhibit large changes in their ter-
minal voltage when a load current is removed, further
discharge after the undervoltage latch has been set is
or begins a relearn cycle on the other battery. To switch
to charge mode, drive RELRN low and CHG high.
Since RELRN overrides CHG, in many applications it is
best to permanently keep CHG high and reduce the IO
needed to control the selector.
When the AC adapter is available, it is used as the
power source for EXTLD unless the RELRN pin is high.
In this state, the charger can be enabled and a
battery charged.
______________________________________________________________________________________
15
相关PDF资料 |
PDF描述 |
|---|---|
| UBT1E222MHD | CAP ALUM 2200UF 25V 20% RADIAL |
| ECO-S2GA391EA | CAP ALUM 390UF 400V 20% SNAP |
| SLP391M180A3P3 | CAP ALUM 390UF 180V 20% SNAP |
| DS2781E+ | IC FUEL GAUGE BATT 8TSSOP |
| EBM15DSEF-S243 | CONN EDGECARD 30POS .156 EYELET |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1538ETI+ | 功能描述:电池管理 Power-Source Select for Dual-Bat System RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| MAX1538ETI+T | 功能描述:电池管理 Power-Source Select for Dual-Bat System RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| MAX1538ETI-T | 功能描述:电池管理 RoHS:否 制造商:Texas Instruments 电池类型:Li-Ion 输出电压:5 V 输出电流:4.5 A 工作电源电压:3.9 V to 17 V 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:VQFN-24 封装:Reel |
| MAX1538EVKIT | 功能描述:电源管理IC开发工具 MAX1538EVKIT RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| MAX153C/D | 功能描述:模数转换器 - ADC RoHS:否 制造商:Texas Instruments 通道数量:2 结构:Sigma-Delta 转换速率:125 SPs to 8 KSPs 分辨率:24 bit 输入类型:Differential 信噪比:107 dB 接口类型:SPI 工作电源电压:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:VQFN-32 |
发布紧急采购，3分钟左右您将得到回复。