参数资料
型号: MAX1879EUA+T
厂商: Maxim Integrated Products
文件页数: 10/11页
文件大小: 0K
描述: IC CHARGER LI+ PULSE 8UMAX
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
功能: 充电管理
电池化学: 锂离子(Li-Ion)
电源电压: 4.4 V ~ 22 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-uMAX
包装: 带卷 (TR)
Simple, Efficient, 1-Cell Li+ Pulse Charger
with current limiting. In most applications, this will be a
small “ wall cube ” switching converter with an output
voltage limit of about 5V or 6V, which is specified as
“ current-limited ” or “ constant current. ”
PMOS Switch
The PMOS FET switches the current-limited source on
and off. Because of the intentionally slow switching
times and limited slew rate, the MAX1879 is not particu-
lar about the power FET it drives. Specifications to con-
sider when choosing an appropriate FET are the
minimum drain-source breakdown voltage, the minimum
turn-on threshold voltage (V GS ), and current-handling
and power-dissipation qualities. The minimum break-
down voltage (BV DS ) must exceed the open-circuit volt-
age of the wall cube by at least 25%. Note that this
open-circuit voltage may be twice as high as the specified
output voltage, depending on the AC adapter type.
Thermistor
The intent of THERM is to inhibit fast-charging the cell
when it is too cold or too hot (+2.5 ° C ≤ T OK ≤ 47.5 ° C),
using an external thermistor. THERM time multiplexes
two sense currents to test for both hot and cold qualifi-
cation. The thermistor should be 10k ? at +25 ° C and
have a negative temperature coefficient (NTC); the
THERM pin expects 3.97k ? at +47.5 ° C and 28.7k ? at
+2.5 ° C. Connect the thermistor between THERM and
GND. If no temperature qualification is desired, replace
the thermistor with a 10k ? resistor. Thermistors by
Philips (22322-640-63103), Cornerstone Sensors
(T101D103-CA), and Fenwal Electronics (140-103LAG-
RB1) work well.
Bypass Capacitors
Bypass the ADJ pin with a 2000pF ceramic capacitor.
Bypass BATT with a capacitor with a value of at least
1.5μF per amp of charge current. The MAX1879 has a
built-in protection feature that prevents BATT from rising
above 5.5V. The device recognizes a rapid rise at BATT,
indicating that the cell is being removed with the FET on.
A capacitor from BATT to GND that ’ s too small does not
give the MAX1879 adequate time to shut off the FET.
BATT may then rise above 6V (towards the open-circuit
source voltage), violating the absolute maximum rating
and damaging the device.
In applications where the cell is removable, very large
capacitance values make it increasingly difficult to iden-
tify momentary cell removal events and may increase
transient currents when the cell is replaced. Therefore,
values in excess of 100μF should be avoided in those
cases. For best system performance, at least 0.47μF of
the total capacitance should be low-ESR ceramic.
Layout Guidelines
The MAX1879 controls the GATE slew rate. The layout is
not as sensitive to noise as a high-frequency switching
regulator. In addition, since the cell voltage is sensed
both during and between high-current pulses, the sys-
tem is insensitive to ground drops. However, Maxim rec-
ommends establishing good grounding areas and large
traces for high-current paths.
Chip Information
TRANSISTOR COUNT: 4692
SUBSTRATE CONNECTED TO GND
10
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相关代理商/技术参数
参数描述
MAX1879EVKIT 制造商:Maxim Integrated Products 功能描述:SMALLEST, SIMPLE 1-CELL LI- PULSE CHARGER WIT - Bulk
MAX187ACPA 功能描述:模数转换器 - ADC Integrated Circuits (ICs) 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
MAX187ACPA+ 功能描述:模数转换器 - ADC 12-Bit 75ksps 5.25V Precision 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
MAX187ACWE 功能描述:模数转换器 - ADC Integrated Circuits (ICs) 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
MAX187ACWE+ 功能描述:模数转换器 - ADC 12-Bit 75ksps 5.25V Precision 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