* Question
What are the main features of the MAXl773/MAXl773A power-selector chip?
* Answer
The MAX1773/MAX1773A are advanced power-selector chips from Maxim Integrated, designed primarily for portable systems such as notebooks and handheld devices that require seamless power source transitions. Here are their main features:
Dual Power-Source Management
Automatic Power-Source Selection: These chips intelligently choose between an AC adapter and a battery based on availability and priority.
Ideal Diode Behavior: They emulate ideal diode operation to prevent reverse current and minimize voltage drops during source switchover.
Integrated High-Side MOSFET Control
Controls external N-channel MOSFETs, which are used as high-side switches for both the AC adapter and the battery paths.
Ensures low R_DS(ON) operation and efficient power flow.
Smart Control & Protection Features
Reverse-Current Protection: Prevents current from flowing back into the adapter or battery.
Input Overvoltage Protection: Shuts off power path if the adapter voltage exceeds a safe level.
Undervoltage Lockout (UVLO): Disables outputs if input voltage is too low, protecting system integrity.
Thermal Protection: Includes thermal shutdown for safety.
Programmability & Status Feedback
Adapter Detection Threshold: Can be configured via resistor divider.
ACOK (AC Adapter OK) Output: Open-drain status pin to indicate presence of a valid adapter.
Power-Path Prioritization: Automatically prioritizes adapter over battery to preserve battery life.
Compact & Efficient Design
Works in systems with:
Adapter voltages typically up to 26V
Battery voltages from 2.5V to 24V
Available in space-saving TQFN or QSOP packages, making them ideal for mobile designs.
Applications
Notebook and sub-notebook computers
Portable instrumentation
Battery-powered consumer electronics
Systems needing seamless transition between power sources
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