Applications powered by lithium ion (Li+), alkaline, NiMH, and lead-acid chemistries use step-up (boost), step-down (buck), or step-up/step-down switching regulators to efficiently convert battery power to the regulated voltages needed for the system. The battery configuration, single- or multi-cell, is selected by the designer. Multi-cell configurations consist of cells connected in series, parallel, or some combination. The selected switching regulator type depends on the battery configuration and the required input voltage range for the design.
Coin cell powered applications that require multiple power rails can benefit from a PMIC (power management IC). These multi-function ICs usually feature step-up/step-down regulators, step-up regulators and low-dropout (LDO) regulator outputs.
Here are some recommended Maxim switching regulators and PMICs for use with different battery configurations.
Devices powered from a single Li+ cell can use either step-up or step-up/step-down converters to generate stable voltage rails. The voltage output of a single -cell Li+ battery typically ranges from 2.7V to 4.2V. If the desired voltage rail falls within this range (e.g., 3.3V), then a step-up/step-down converter typically provides the best solution. If the desired voltage rail is above this range(e.g., 5V), then a step-up converter provides the best solution.
Multi-rail applications powered by single cell Li+ batteries, can benefit from an integrated PMIC to achieve high conversion efficiency and space savings.
Alkaline or NiMH single-cell powered devices generally use one or more step-up (boost) regulators. This applies to standard AA-type batteries and small coin cells that have output voltages in the range of 0.8V to 1.8V.
Battery applications that have higher power needs often connect batteries in parallel or series to provide the increased total energy need. These battery configurations usually provide higher output voltages than the application rail. In these applications, step-down (buck) regulators convert the high variable input voltage into lower regulated output voltage rails.
High capacity, 12V sealed gel batteries are popular in many applications because they are cost effective and can be easily recharged.
If you're looking for switching regulators for battery-powered applications and want extra features like an integrated battery charger, view our PMIC Applications page. If you're looking for a standalone battery-charger IC, see our Battery Management page.
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