Synchronous buck converter minimises switching losses

It is in stock at distributor Anglia Components.

The 5W device has integrated MOSFETs and can deliver up to 1.9A of primary sink current and operates over a wide input voltage range of 4.5 V to 38 V.

The device features high efficiency; this is achieved using synchronous rectification and an advanced control algorithm that minimises switching losses.

It has a programmable switching frequency which can be set from 250kHz to 1MHz, allowing designers to optimize the converter's performance for their specific application.

The device’s isolation capability makes it suitable for use in applications that require galvanic isolation between the input and output circuits.

It is used with a transformer to provide the isolation and can help designs meet the safety requirements of a variety of industry standards such as IEC 60950-1 and UL 60950-1 without using an optocoupler.

Built-in protection features, including overvoltage protection, internal primary current limiting, and thermal shutdown. These features help to ensure the reliability and safety of the device in a variety of operating conditions.

An integrated P-Channel MOSFET implemented as a high-side power switch allows the device to operate with a 100% duty cycle.

Primary output voltage of the device is regulated and can be accurately adjusted, whereas the isolated secondary output is derived by using a given transformer ratio.

The device does not require an optocoupler to provide isolation, and it has primary sink capability up to 1.9 A (even during soft-start) allowing a proper energy transfer to the secondary side as well as enabling a tracked soft-start of the secondary output.

The device’s control loop is based on a peak current mode architecture, and it operates in forced PWM. The device also has a 300 ns blanking time to filter any oscillations generated by the transformer leakage inductance, making the solution more robust.

Pulse by pulse current sensing on both power elements provides an effective constant current protection in the primary side and due to the primary reverse current limit, the secondary output is also protected against short circuit events. A primary output voltage supervisor, which notifies primary output voltage regulation through the RST open collector output, overvoltage protection, adjustable switching frequency, synchronisation and a programmable soft-start are also available.

The L69861is housed in an exposed pad HTSSOP16 package offering improved thermal resistance and has an operating temperature range of -40°C to +150°C.

The device is also available in Automotive grade, part number A69681, which is AEC-Q100 Grade 1 qualified and available in the same package and operating temperature range.