PM6686

Overview

The PM6686 is a dual step-down controller designed for high-efficiency conversion in laptop power systems. It features lossless current sensing and constant on-time architecture for fast transient response. The input voltage range spans from 5.5 V to 28 V, supporting two independent outputs with selectable switching frequencies. An embedded linear regulator provides up to 100 mA at 3.3 V/5 V or adjustable voltages from 0.7 V to 4.5 V. The device operates within a temperature range of -40°C to 85°C and utilizes a 32-VFQFN package.

Feature Summary

• Dual step-down control with lossless current sensing and constant on-time architecture
• Embedded linear regulator with switchover capability between LDO and switching outputs
• Selectable minimum switching frequency to avoid audio noise issues
• Independent Power Good and Enable signals with latched overvoltage and undervoltage protection

Applications

• Laptop power system controllers
• Dual output DC-DC conversion circuits
• Systems requiring low-noise operation at light loads

Procurement Notes

Verify the specific ordering suffix against the manufacturer datasheet to ensure correct packaging and temperature grade. Confirm that the required switching frequency configuration matches the available selectable options. Check lead times as production cycles may vary based on order volume and manufacturing schedules.

Selection Notes

Select this component when designing dual-output power supplies for portable computing devices. Ensure the input voltage stays within the specified 5.5 V to 28 V range. Consider the thermal performance of the 32-VFQFN package for the intended application environment.

Part Context

This part belongs to STMicroelectronics' portfolio of power management integrated circuits. It is specifically engineered for mobile platforms where efficiency and transient response are critical. The device complements other CPU and memory power solutions in the company's notebook reference designs.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Consult official distributor databases for cross-reference information if alternative sourcing is required.

FAQ

What is the purpose of the embedded linear regulator?

The embedded linear regulator provides an additional output capable of delivering up to 100 mA, which can be bypassed by switching regulator outputs or an external supply via a switchover function.

How does the device handle light load conditions?

It employs a pulse skipping technique to increase efficiency at very light loads while maintaining a selectable minimum switching frequency to prevent audio noise.