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1节至3节电池、大功率、低噪声、升压型DC-DC转换器

集成2路ADC,提供精确的电池电压监测

产品详情

主要特征

应用/用途

Parametric specs for Step-Up Switching Regulators
VIN (V) (min) 0.7
VIN (V) (max) 5.5
VOUT1 (V) (min) 2.7
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 0.3
Switch Type Internal
Preset VOUT (V) 3.3
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
ICC (mA) (typ) 0.035
Shutdown Mode Supply Current (µA) (typ) 4
Shutdown Mode Supply Current (µA) (max) 20
# DC-DC Outputs 1
Switching Frequency (kHz) 400
Package/Pins SOIC (N)/16
Budgetary
Price (See Notes)
2.5
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参量

Parametric specs for Step-Up Switching Regulators
VIN (V) (min) 0.7
VIN (V) (max) 5.5
VOUT1 (V) (min) 2.7
VOUT1 (V) (max) 5.5
IOUT1 (A) (max) 0.3
Switch Type Internal
Preset VOUT (V) 3.3
Output Adjust. Method Preset
Resistor
Synchronous Switching? Yes
ICC (mA) (typ) 0.035
Shutdown Mode Supply Current (µA) (typ) 4
Shutdown Mode Supply Current (µA) (max) 20
# DC-DC Outputs 1
Switching Frequency (kHz) 400
Package/Pins SOIC (N)/16
Budgetary
Price (See Notes)
2.5

主要特征

  • Up to 95% Efficiency
  • 3.3V Dual Mode™ or 2.7V to 5.5V Adj. Output
  • 0.7V to 5.5V Input Range
  • 0.15mW Standby Mode
  • 300kHz PWM Mode or Synchronizable
  • Two-Channel ADC with Serial Output
  • Power-Good Function

应用/用途

  • 蜂窝电话
  • 数字无绳电话
  • 手持式仪表(PDA、掌上电脑)
  • 本地3.3V至5V转换电源
  • 掌上电脑
  • PCS电话
  • 个人通信装置

描述

The MAX848/MAX849 boost converters set a new standard of high efficiency and high integration for noise-sensitive power-supply applications, such as portable phones and small systems with RF data links. The heart of the these devices is a synchronous boost-topology regulator that generates a fixed 3.3V output (or 2.7V to 5.5V adjustable output) from one to three NiCd/NiMH cells or one Li-Ion cell.

Synchronous rectification provides a 5% efficiency improvement over similar nonsynchronous boost regulators. In standby mode, pulse-skipping PFM operation keeps the output voltage alive with only 150µW quiescent power consumption. Fixed-frequency PWM operation ensures that the switching noise spectrum is limited to the 300kHz fundamental and its harmonics, allowing easy post-filtering noise reduction. For even tighter noise spectrum control, synchronize to a 200kHz to 400kHz external clock.

Battery monitoring is provided by a two-channel, voltage-to-frequency analog-to-digital converter (ADC). One channel is intended for a single-cell battery input (0.625V to 1.875V range), while the other channel is for monitoring higher voltages (0V to 2.5V range).

Two control inputs are provided for push-on, push-off control via a momentary pushbutton switch. Upon power-up, an internal comparator monitors the output voltage to generate a power-good output (POK).

The devices differ only in the current limit of the N-channel MOSFET power switch: 0.8A for the MAX848, and 1.4A for the MAX849.

简化框图

MAX848、MAX849:典型工作电路 MAX848、MAX849:典型工作电路 Zoom icon

技术文档

支持和培训

在Maxim的知识库中搜索技术问题的答案

过滤搜索

Maxim的专业工程师团队也会为您解答相应的技术问题,请访问Maxim的 支持中心