L6571A and L6571B are high voltage half bridge drivers with built-in oscillator from ST Microelectronics. The frequency of the oscillator can be programmed using external resistor and capacitor. The internal circuitry of the device also allows it to be driven by external logic signal. The output drivers are designed to drive external n-channel power MOSFET and IGBT. The internal logic assures a dead time to avoid cross-conduction of the power devices. Two version are available: L6571A and L6571B. They differ in the internal dead time: 1.25µs and 0.72µs (typ.).
The L6571A and L6571B are high‑voltage half‑bridge driver ICs that integrate an oscillator and provide programmable dead‑time. They are intended to drive external N‑channel power MOSFETs or IGBTs and include built‑in protection features such as a Zener clamp and ESD immunity.
The device operates from a supply voltage up to 500 V, offers a typical oscillator frequency of 200 kHz, and can source 170 mA or sink 270 mA per driver. Detailed electrical characteristics, pin functions, and mechanical dimensions are provided in the following sections.
| Oscillator Frequency (typical) | 200 kHz |
|---|---|
| Dead Time (L6571A) | 1.25 µs |
| Dead Time (L6571B) | 0.72 µs |
| Driver Sink Current | 270 mA |
| Driver Source Current | 170 mA |
| Zener Clamp Voltage | 15.6 V (typ.) |
| dV/dt Immunity | ±50 V/ns |
The L6571A has an internal dead time of 1.25 µs.
The driver can operate with a supply voltage up to 500 V.
The oscillator frequency is programmed by an external resistor and capacitor connected to pins RF and CF.
The internal Zener clamp on VS is typically 15.6 V.