L6571A

Overview

The L6571A is a high-voltage half-bridge gate driver IC manufactured by STMicroelectronics, designed for driving external N-channel power MOSFETs and IGBTs. It features a built-in programmable oscillator with frequency set by external RC components, or it can be driven by an external logic signal. The device provides synchronous drive outputs with a fixed internal dead time of 1.25µs to prevent cross-conduction. Key electrical parameters include a supply voltage range of 10V to 16.6V, a maximum high-side bootstrap voltage of 600V, and peak output currents of 170mA (source) and 270mA (sink). It operates within a junction temperature range of -40°C to 150°C.

Feature Summary

• Integrated high-voltage half-bridge driver capable of supporting up to 600V self-bootstrapped operation.
• Built-in programmable oscillator allows frequency customization via external resistor and capacitor, or accepts direct logic input.
• Fixed internal dead time of 1.25µs ensures safe switching by preventing simultaneous conduction of high-side and low-side devices.
• High dV/dt immunity up to ±50V/ns protects against false triggering in noisy environments.

Applications

• Electronic ballasts for fluorescent lamps
• Half-bridge resonant converters
• Induction heating systems
• High-voltage motor control applications

Procurement Notes

Verify the specific suffix 'A' to confirm the 1.25µs dead time characteristic, as the 'B' variant offers 0.72µs. Confirm package compatibility with 8-MiniDIP footprints. Check current stock status as the component may be subject to obsolescence notices. Ensure supplier documentation matches the official STMicroelectronics datasheet for the L6571(A,B) series to validate technical specifications.

Selection Notes

Select the L6571A when a fixed 1.25µs dead time is required for robust protection against shoot-through in half-bridge topologies. Choose this device over the L6571B if slower switching speeds are acceptable or if the longer dead time better suits the specific gate charge requirements of the connected power devices. Consider the 600V high-side capability for applications requiring significant voltage isolation between the driver ground and the high-side switch source.

Part Context

The L6571A belongs to the L6571 family of high-voltage half-bridge drivers from STMicroelectronics. It is part of a broader portfolio of lighting control and power management ICs designed for compact, efficient systems. The family includes variants like the L6571B with different dead times and other integrated ballast controllers such as the L6574, which adds preheat and dimming functions specifically for CFL/TL lamps.

Replacement Considerations

The L6571B is a direct functional substitute within the same package but features a shorter typical dead time of 0.72µs compared to the L6571A's 1.25µs. Designers must verify that the reduced dead time does not compromise safety margins in their specific application before substituting.