L6571B

Overview

The L6571B is a high voltage half bridge driver with a built-in oscillator. It features a typical internal dead time of 0.72µs to prevent cross-conduction. The device supports n-channel power MOSFET and IGBT outputs with sink current of 270mA and source current of 170mA. Operating supply voltage ranges from 10V to 16.6V, with a high voltage rail up to 600V. It includes under voltage lockout with hysteresis, dV/dt immunity up to ±50V/ns, and a 15.6V Zener clamp on VSB.

Feature Summary

• Built-in programmable oscillator frequency controlled by external resistor and capacitor
• Internal logic ensures dead time to avoid cross-conduction of power devices
• High voltage rail capability up to 600V for robust operation
• Very low startup current of 150µA utilizing BCD off-line technology

Applications

• Driving n-channel power MOSFET in half-bridge topologies
• Driving IGBT in high voltage switching applications
• Electronic ballast designs for fluorescent lamps
• CFL and TL lamp control systems

Procurement Notes

Verify the specific suffix 'B' to confirm the 0.72µs typical dead time characteristic, as the 'A' variant offers 1.25µs. Confirm package availability matches the required 8-pin PDIP or MiniDIP form factor. Check component status as some distributors list this part as obsolete or end-of-life. Ensure input signal compatibility with RC input circuit requirements specified in the datasheet.

Selection Notes

Choose the L6571B over the L6571A when a shorter dead time of 0.72µs is required for higher frequency operation or efficiency. Select this device if the application demands a high voltage rail up to 600V. Consider the integrated oscillator feature if external clocking is not preferred. Verify that the 150µA startup current meets the system's power-up constraints.

Part Context

The L6571 series belongs to STMicroelectronics' portfolio of lighting control ICs and gate drivers. It is designed for compact and robust solutions in fluorescent lamp control and high-voltage driving applications. The device integrates gate driving, timing, and protection functions to reduce external component count. It complements other ballast controllers like the L6574 and L6382D in complete lighting system architectures.

Replacement Considerations

The L6571A is the primary alternative within the same family, differing only in the internal dead time specification (1.25µs vs 0.72µs). No other direct substitute part numbers are confirmed in the provided documentation.