- 您现在的位置：买卖IC网 > PDF目录13562 > MAX1817EUB+ (Maxim Integrated Products)IC REG BOOST 125MA DL 10UMAX PDF资料下载
参数资料
| 型号： | MAX1817EUB+ |
| 厂商： | Maxim Integrated Products |
| 文件页数： | 7/12页 |
| 文件大小： | 0K |
| 描述： | IC REG BOOST 125MA DL 10UMAX |
| 产品培训模块： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 标准包装： | 50 |
| 类型： | 升压（升压） |
| 输出类型： | 两者兼有 |
| 输出数： | 2 |
| 输出电压： | 3.3V 或可调主电源，-28 V ~ 28 V 或可调副电源 |
| 输入电压： | 1.5 V ~ 5.5 V |
| 频率 - 开关： | 500kHz |
| 电流 - 输出： | 125mA |
| 同步整流器： | 无 |
| 工作温度： | -40°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 10-TFSOP，10-MSOP（0.118"，3.00mm 宽） |
| 包装： | 管件 |
| 供应商设备封装： | 10-µMAX |
Compact, High-Efficiency, Dual-Output
Step-Up DC-DC Converter
Pin Description
PIN
1
2
3
4
5
6
7
8
9
10
NAME
FB
ON
ONLCD
FBLCD
AGND
N.C.
LXLCD
GND
LX
OUT
FUNCTION
Main Output Feedback Input. Connect FB to GND for fixed 3.3V main output. For other output
voltages, use a resistive voltage-divider to set the output voltage. The feedback regulation voltage
is 1.25V at FB.
Main Step-Up Converter On/Off Control. Connect ON to OUT for automatic startup. Connect ON to
GND to put the IC into shutdown mode.
LCD Output On/Off Control. Connect ONLCD to OUT to enable the LCD output. Connect ONLCD
to GND to disable the LCD output. The main output must be ≥ 2.4V to enable the LCD output.
LCD Output Feedback Input. Use a resistive voltage-divider from the LCD output to FBLCD to set
the voltage. The feedback regulation voltage is 1.25V at FBLCD.
Analog Ground. Connect AGND to GND as close to the IC as possible.
No Connection. Not internally connected.
LCD Output Switching Node. Drain of the internal N-channel MOSFET that drives the LCD output.
Connect an external inductor and rectifier to LXLCD.
Power Ground. Connect GND to AGND as close to the IC as possible.
Main Output Switching Node. Drain of the internal N-channel MOSFET that drives the main output.
Connect an external inductor and rectifier to LX.
Main Step-Up Converter Output. OUT is used to measure the output voltage in fixed mode (FB =
GND) and is the internal bias supply input to the IC. When shut down (ON = ONLCD = GND), OUT
is high impedance, drawing 1μA (max).
________________Detailed Description
The MAX1817 dual step-up converter is designed to
supply the main power and LCD bias for low-power,
hand-held devices. The MAX1817 ’ s main step-up con-
verter includes a 0.35 ? N-channel power MOSFET
switch and provides a fixed 3.3V or adjustable 2.5V to
5.5V output at up to 125mA from an input as low as
1.5V. The MAX1817 ’ s LCD bias step-up converter
includes a high-voltage 1.1 ? power MOSFET switch to
support as much as 5mA at 28V (Figure 1). During
startup, the MAX1817 extends the LCD MOSFET switch
minimum off-time, limiting surge current. Both convert-
ers require an inductor and external rectifier.
The MAX1817 runs in bootstrap mode, powering the IC
from the main step-up converter ’ s output. Independent
logic-controlled shutdown for the main and LCD step-
up converters reduces quiescent current to 0.1μA.
Main Step-Up Converter
The MAX1817 main step-up converter runs from a
+1.5V to +5.5V input voltage and produces a fixed 3.3V
or adjustable 2.5V to 5.5V output voltage as well as
biasing the internal control circuitry. The MAX1817
switches only as often as is required to supply sufficient
power to the load. This allows the converter to operate
at lower frequencies at light loads, improving efficiency.
The control scheme maintains regulation when the error
amplifier senses the output voltage is below the feed-
back threshold, turning on the internal N-channel MOS-
FET and initiating an on-time. The on-time is terminated
when the 0.75A current limit is reached or when the
maximum on-time is reached. The N-channel MOSFET
remains off until the inductor current drops to 0, forcing
discontinuous inductor current. At the end of a cycle,
the error comparator waits for the voltage at FB to drop
below the regulation threshold, at which time another
cycle is initiated.
The main step-up converter uses a startup oscillator to
allow it to start from an input voltage as low as +1.2V.
This is necessary since the control circuitry is powered
from the step-up converter output (OUT). When the
voltage at OUT is below the OUT undervoltage lockout,
a fixed 50% duty cycle drives the internal N-channel
MOSFET, forcing the main output voltage to rise. Once
_______________________________________________________________________________________
7
相关PDF资料 |
PDF描述 |
|---|---|
| 50THV47M10X10.5 | CAP ALUM 47UF 50V 20% SMD |
| UCW1V100MCL1GS | CAP ALUM 10UF 35V 20% SMD |
| VI-JNX-EX-F1 | CONVERTER MOD DC/DC 5.2V 75W |
| GBB40DHRD | CONN CARD EXTEND 80POS .050" SLD |
| SC63LCB-4R7 | INDUCTOR SMD 4.7UH 1.66A 100KHZ |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX1817EUB+ | 功能描述:直流/直流开关转换器 Dual-Output Step-Up DC/DC Converter 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 |
| MAX1817EUB+T | 功能描述:直流/直流开关转换器 Dual-Output Step-Up DC/DC Converter 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 |
| MAX1817EUB-T | 功能描述:直流/直流开关转换器 Dual-Output Step-Up DC/DC Converter 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 |
| MAX1817EVKIT | 制造商:Maxim Integrated Products 功能描述:COMPACT, HIGH-EFFICIENCY, DUAL-OUTPUT STEP-UP - Bulk |
| MAX1818ESA20 | 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述: |
发布紧急采购，3分钟左右您将得到回复。