ISL6558IR

ISL6558IR Application Field and Working Principle

The ISL6558IR is an integrated, single-channel full-bridge DC–DC synchronous buck controller that uses a high-side, N-channel field-effect transistor (N-FET) & low-side, P-channel field-effect transistor (P-FET) to convert a supply voltage (VIN) into an adjustable, regulated output voltage (VOUT). This converter manages the on-off operation of the power components in order to step down the input voltage within a precise voltage range and provides a payload current at the output. The precise control of the device also enables it to adjust its output voltage under increased load demand.

The ISL6558IR Benefits

• Zero-Ripple Synchronous Converter
• Under-Voltage Lockout Feature
• Selectable Frequency
• Internal 5µA Standby Mode
• Internal Pre-Boost Circuit
• Short-Circuit Protection
• Output Over-Voltage Protection
• Feedback Voltage Monitoring

Applications

The ISL6558IR DC–DC synchronous buck converter is highly suited to a range of applications, such as industrial motor and motor-drive control, LED lighting, LED displays, notebook and tablet battery chargers, telecom/server/data-centre power systems, automotive battery charging systems and many other applications.

Working Principle of ISL6558IR

The ISL6558IR synchronous buck converter controller is based on a pulse-width modulation (PWM) switching topology. The converter uses a high-side N-FET and low-side P-FET switch driver to drive their respective FETs for power conversion. The switch driver simultaneously controls both FETs and uses current measurements to manage the rest of the power components on the circuit, such as inductor and output capacitor. The output of the converter is controlled via a voltage feedback loop, which regulates the average, output voltage (VOUT).

The device’s under-voltage lockout (UVLO) function prevents the converter from entering the normal operating mode if the input voltage (VIN) is less than the UVLO threshold voltage. The ISL6558IR also has an internal pre-boost circuit that enables the device to start quickly and a 5µA standby mode to reduce overall power consumption and extend battery life in applications. Additionally, the ISL6558IR integrates functional fault protection features that protect against output over-voltage, output short-circuit and ov-temperature conditions. Overall, this DC–DC synchronous buck converter provides a highly accurate, efficient and configurable solution for power management designs.