ON Semiconductor Introduces Adaptive Charging Controller for USB PD 3.0March 02, 2020 by Gary Elinoff
The FAN6390MPX incorporates an autonomous USB PD state machine to comply with the USB PD 3.0 specification.
ON Semiconductor has announced its first family of USB-C PD 3.0 Programmable Power Supply (PPS) controllers, FAN6390. The new family is in compliance with PPS rules, which allow for control of currents and voltages ranging from 1 A to 3 A and 3.3 V to 21 V. ON Semiconductor claims that these devices will enable OEM’s to meet a wide range of applications and power levels.
The FAN6390MPX adaptive USB type-C charging controller. Image used courtesy of ON Semiconductor
The FAN6390 family operates over a -40°C to +125°C temperature range. It is available in a 24-lead, WQFN24 4 mm x 4 mm package.
Key Features of the PPS Controllers
The FAN6390 is a secondary side power adapter supporting synchronous rectification (SR). The device maintains constant voltage (CV) and constant current (CC) regulation using two open-drain type op-amps for dual−loop CV/CC control.
The unit can deliver a maximum of 60 W.
Block diagram of the FAN6390. Image used courtesy of ON Semiconductor
Output voltage, output current, and external temperature are monitored through a 10-bit ADC designed to allow the device to support both over- and under-voltage output protection as well as protection against over-temperature. There is also protection against cable faults.
The FAN6390’s state machine supports both single source and PPS designs.
ON Semiconductor claims the BOM count for OEMs is decreased by the CC and CV blocks, as well by the internal SR control and an NMOS gate driver for VBUS load switch control.
The PPS Standard
PPS, part of the USB PD 3.0 standard, refers to the exchange of data between a power supply and the device's undercharge. The data exchange is periodic during the course of the charge.
PPS mode essentially allows different amounts of power to be delivered to a device instead of just a constant stream of power. This allows for the fastest possible charging while accounting for the safety and longevity of the device being charged. This is especially important where lithium-ion batteries are concerned.
As described by ON Semiconductor’s Scott Haddow, “The trend of higher capacity batteries requiring the same or faster charging times is accelerating the adoption of USB-C PD. The family of FAN6390 products enables an impressive level of integration, which will enhance industrial design and improve power density for travel adapters.”
He goes on to say that “the optimized architecture provides state machine-based operation for all features required for PD 3.0 and PPS functionality lending to ease of end product design and manufacturing. The FAN6390 yields high efficiency through industry-leading synchronous rectifier FET driving techniques.”
Source and Sink
One of the hallmarks of the USB-Type-C specification is the ability of a device to specify a source or user of power. The diagram below illustrates that information being communicated via the CC1 and CC2 lines of a USB Type-C cable.
Diagram of a source-only device connected to a sink device using a Type C cable. Image used courtesy of ON Semiconductor
When no sink (power using) device is detected by the CC lines, the NMOS load switch on the top left of the above diagram prevents DC power from reaching the VBUS.
The FAN6390's default power profile. Image (modified) used courtesy of ON Semiconductor
The USB PD 3.0 specification defines power-data objects (PDO) and augmented power data objects (APDO) as a way for devices to communicate power capabilities. The Fan6390’s default power profile recognizes three APDOs and four PDOs, as illustrated in the above image. APDOs are described as a power supply whose output voltage can be adjusted across a defined range.
Designed for Battery Chargers
The FAN6390 will find applications in battery chargers for smartphones, tablets, and PCs.
Application for the FAN6390 as a secondary side power adapter supporting SR. Image used courtesy of ON Semiconductor
It will also serve in AC-DC adapters for devices that require CV or CC control.
Around the Industry
The TPS65983B from Texas Instruments is a USB Type-C and power delivery (PD) controller. When the cable is detected, the unit communicates using the CC wire employing the USB PD protocol. Once complete, the unit enables the appropriate power path.