Battery rectifiers' are devices that are used to charge and maintain batteries, especially in industrial or power applications. A rectifier is a device that converts alternating current (AC) to direct current (DC) by periodically changing the direction of the current.
Battery rectifiers are essential for charging batteries, as most batteries require direct current to charge effectively. In the context of battery charging, rectifiers are used in combination with chargers to provide the DC current needed to charge batteries.
The voltage of a rectified alternator output can contain AC voltage ripple superimposed on the battery voltage during the entire life time of the vehicle, depending on the operating conditions.
Active rectification of AC ripple results in lower power dissipation in MOSFET and output electrolytic capacitors. Efficient active rectification of AC ripple superimposed on DC voltage leads to a reduced RMS ripple current and improved power supply rejection ratio (PSRR).
The reverse battery protection circuit is verified for stable operation with AC voltage ripple superimposed on the battery supply line. This is done according to different automotive test standards.
Rectification of AC voltage ripple is important in automotive ECU designs for applications such as Sensor Fusion, which can have capacitance in the order of a few milli-Farads. This rectification at the input helps improve the PSRR of the supply, which is beneficial for the Audio Amplifier sub-system.