MAX849
LAST TIME BUY1-Cell-to-3-Cell, High-Power, Low-Noise, Step-Up DC-DC Converters
Integrated 2-Channel ADC Allows Accurate Battery Voltage Monitoring
- Part Models
- 2
- 1ku List Price
- Starting From $3.52
Overview
- 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
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.
Applications
- Cell Phones
- Digital Cordless Phones
- Handheld Instruments (PDAs, Palmtops)
- Local 3.3V to 5V Supplies
- Palmtop Computers
- PCS Phones
- Personal Communicators
Documentation
Data Sheet 1
Technical Articles 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| MAX849ESE+ | Small-Outline IC Narrow (0.15in) | ||
| MAX849ESE+T | Small-Outline IC Narrow (0.15in) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Mar 13, 2023 - 2361N WAFER FAB |
||
| MAX849ESE+ | ||
| MAX849ESE+T | Obsolete | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
Can't find the software or driver you need?
Request a Driver/SoftwareHardware Ecosystem
| Parts | Product Life Cycle | Description |
|---|---|---|
| Battery Charger ICs 1 | ||
| MAX847 | PRODUCTION | 1 Cell, Step-Up Two-Way Pager System IC |
Evaluation Kits
Evaluation Kit for the MAX848, MAX849
Features and Benefits
- 250mA to 850mA Output Current!
- 90% Efficiency
- Proven PC Board Layout
- Fully Assembled and Tested
- 2-Channel Analog-to-Digital Converter (ADC) with Serial Output for Voltage Monitoring
Product Details
The MAX849 evaluation kit (EV kit) is an assembled and tested PC board that implements a complete, one-cell to three-cell, high-power, low-noise, step-up DC-DC power converter that's ideal for portable phones and other battery-operated equipment. With a 3.3V output voltage, use one or two cells to get a 250mA to 700mA output current. With a 5V output voltage, use three cells or one lithium-ion (Li-Ion) battery to get an 850mA output current.
The board includes clips for a standard AA-size battery, and provides a 10-pin header for user interfacing.
To evaluate the MAX848, order a free sample of the MAX848ESE along with the MAX849 EV kit.
Applications
- Cell Phones
- Digital Cordless Phones
- Handheld Instruments (PDAs, Palmtops)
- Local 3.3V to 5V Supplies
- Palmtop Computers
- PCS Phones
- Personal Communicators
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