MAX1773

Obsolete

Power Source Selector for Dual-Battery Systems

Power Source Selector Minimizes System Cost and Complexity

Data Sheet (Rev. 2) Product Selection Table

Viewing:

Overview

7-MOSFET Topology Offers Low-Cost Solution
Automatically Detects and Responds to:
- Low Battery Voltage Condition
- Battery Insertion and Removal
- AC Adapter Presence
Direct Drive of P-Channel MOSFETs
Simplifies Power Management µP Firmware
Extends Battery Life by Allowing Power Management µP to Enter Standby
4.75V to 28V AC Adapter Input Voltage Range
Integrated LDO with 1mA Drive Capability
Small Footprint 20-Pin TSSOP Package

The MAX1773/MAX1773A highly integrated ICs serve as the control logic for a system with multiple power sources. They directly drive external P-channel MOSFETs to select from an AC adapter and dual battery sources for charge and discharge. The selection is made based on the presence of the power sources and the state of the batteries. The MAX1773/MAX1773A detect low battery conditions using integrated analog comparators and check for the presence of a battery by using battery thermistor outputs.

The MAX1773/MAX1773A are designed for use with a buck topology charger. They provide a simple and easily controlled solution to a difficult analog power control problem. The MAX1773/MAX1773A provide most of the power source monitoring and selection, freeing the system power management microprocessor (µP) for other tasks. This not only simplifies development of the power management firmware for the µP but also allows the µP to enter standby, thereby reducing system power consumption.

The MAX1773A is recommended for new designs.

Applications

Dual-Battery Portable Equipment
Internet Tablets
Notebook and Subnotebook Computers
PDAs and Handy-Terminals

Documentation

Data Sheet 1

MAX1773-MAX1773A: Power Source Selector for Dual-Battery Systems Data Sheet (Rev.2) 05/15/2017

Reliability Data 1

MAX1773 Reliability Data 01/12/2023

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/Software

Hardware Ecosystem

Parts	Product Life Cycle	Description
Battery Charger ICs 2
MAX1772	PRODUCTION	Low-Cost, Multichemistry Battery-Charger Building Block
MAX1645A		Advanced-Chemistry-Independent, Level-2 Battery Chargers with Input Current Limiting

Evaluation Kits

Evaluation Kit for the MAX1773

Buy Now View Details

Features and Benefits

+4.75V to +28V AC-Adapter Input Range
Up to 5A Steering Capability
P-Channel MOSFET Steering Switches
Adjustable Battery Minimum Voltage Level
SMBus Multiplexer
AC-Present and Battery-Status LEDs
Interfaces to MAX1772EVKIT Battery Charger
Surface-Mount Components
Fully Assembled and Tested

Product Details

The MAX1773 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that routes charge and discharge currents between two battery packs, a buck step-down Battery Chargers, and an AC-adapter power source. The circuit uses a MAX1773 IC in a 20-pin TSSOP package and is configured for an AC-adapter input range of +4.75VDC to +28VDC.

The EV kit uses seven P-channel MOSFETs to steer current between the power sources and the load. The battery minimum voltage level sets the threshold for battery undervoltage conditions and can be adjusted from +4.65V to +13V.

The EV kit features an SMBus™ signal multiplexer that routes SMBus signals for the smart battery packs. LEDs are provided to indicate the status of the AC adapter and battery packs. The MAX1773 EV kit also demonstrates low-current usage with several options to reduce current usage.