The L6382D5 is suitable for microcontrolled electronic ballasts embedding a PFC stage and a half-bridge stage. The L6382D5 includes 4 MOSFET driving stages (for the PFC, for the half bridge, for the preheating MOSFET) plus a power management unit (PMU) featuring also a reference able to supply the microcontroller in any condition.
Besides increasing the application efficiency, the L6382D5 reduces the bill of materials because different tasks (regarding drivers and power management) are performed by a single IC, which improves the application reliability.
Designed in High-voltage BCD Off-line technology, the L6382D5 is provided with 4 inputs pin and a high voltage start-up generator conceived for applications managed by a microcontroller. It allows the designer to use the same ballast circuit for different lamp wattage/type by simply changing the μC software.
The digital input pins - able to receive signals up to 400KHz - are connected to level shifters that provide the control signals to their relevant drivers; in particular the L6382D5 embeds one driver for the PFC pre-regulator stage, two drivers for the ballast half-bridge stage (High Voltage, including also the bootstrap function) and the last one to provide supplementary features like preheating of filaments supplied through isolated filaments in dimmable applications.
A precise reference voltage (+5V±2%) able to provide up to 30mA is available to supply the μC in operating mode. Instead, during start-up and save mode the current available at VREF is up to 10mA and it is provided by the internal high voltage start-up generator.
The chip has been conceived with advanced power management logic to minimize power losses and increase the application reliability.
In the half-bridge section, a patented integrated bootstrap section replaces the external bootstrap diode.
The L6382D5 integrates also a function that regulates the IC supply voltage (without the need of any external charge pump) and optimizes the current consumption.
ST L6382D5TR