参数资料
型号: MAX1688ESA+T
厂商: Maxim Integrated Products
文件页数: 8/12页
文件大小: 0K
描述: IC REG BOOST SYNC ADJ 2.5A 8SOIC
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
类型: 升压(升压)
输出类型: 可调式
输出数: 1
输出电压: 1.25 V ~ 6 V
输入电压: 2.7 V ~ 6 V
PWM 型: 电流模式
频率 - 开关: 1MHz
电流 - 输出: 2.5A
同步整流器:
工作温度: -40°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 8-SOIC(0.154",3.90mm 宽)
包装: 带卷 (TR)
供应商设备封装: 8-SOIC
Step-Up DC-DC Converters with
Precise, Adaptive Current Limit for GSM
I PEAK
SET BY
V LIM (V CHG )
I PEAK - 200mA
TIME
( ) ARE FOR MAX1688
Figure 2. Hysteretic Inductor Current
OUT
HYSTERESIS
BAND
V OUT
I LOAD
V OUT
“ON”
CONTROL INPUT
TIME
Figure 4. Timing Diagram of “ON”
Applications Information
Adjusting the Output Voltage
Adjust the MAX1687/MAX1688 output voltage with two
external resistors (Figure 3). Choose R2 to be between
10k ? to 100k ? . Calculate R1 as follows:
MAX1687
MAX1688
FB
R1
R1 = R2 · (V OUT - V FB ) / V FB
where V FB is the feedback threshold voltage, 1.25V
nominal.
R2
Adjusting Current Limit (MAX1687)
The MAX1687 has an adjustable current limit for appli-
cations requiring limited supply current, such as PC
( V FB FB )
R1 = R2
V OUT -V
card sockets or applications with variable burst loads.
For single Li-Ion battery cell applications, the high peak
Figure 3. Setting the Output Voltage
Synchronized ON Pin
If desired, drive ON low during periods of high current
demand to eliminate switching noise from affecting
sensitive RF circuitry. During the periods when ON is
low, the output reservoir capacitor provides current to
the load (Figure 4).
Buck Capability
Although the IC is not intended for this application, the
MAX1687/MAX1688 operate as a buck converter when
the input voltage is higher than the output voltage. The
MAX1687/MAX1688 are not optimally efficient in this
mode (see Typical Operating Characteristics for
efficiencies at 2.7V, 3.3V, 5V, and 6V input supply volt-
ages).
current demands of the RF transmitter power amplifier
can pull the battery very low as the battery impedance
increases toward the end of discharge. The reservoir
capacitor at the output supplies power during load-cur-
rent bursts; this allows for a lower input current limit.
With this feature, the life of the Li-Ion battery versus the
reservoir capacitor size trade-off can be optimized for
each application.
8
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相关代理商/技术参数
参数描述
MAX1688EUE 功能描述:直流/直流开关转换器 StepUp w/Prec Adapt Crnt Limit for GSM RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1688EUE+ 功能描述:直流/直流开关转换器 StepUp w/Prec Adapt Crnt Limit for GSM RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1688EUE+T 功能描述:直流/直流开关转换器 StepUp w/Prec Adapt Crnt Limit for GSM RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1688EUE-T 功能描述:直流/直流开关转换器 StepUp w/Prec Adapt Crnt Limit for GSM RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT
MAX1688EUE-T 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: