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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

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) 1
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)
2.86
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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) 1
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)
2.86

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

Technical Docs

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