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Many power-IC announcements are made through the course of a year, which makes it very difficult to narrow a choice of “best” down to just one product. Nonetheless, the “fast charger” reference design developed jointly by Power Integrations and Cypress Semiconductor stood out in 2016. The technology has started to find its way into smartphones, and will no doubt see greater use in the near future.
It’s not the first fast-charger reference design developed by Power Integrations. The company previously introduced a reference design for a Qualcomm Quick Charge 2.0-enabled power supply, called the DER-381. It detects commands from a Quick Charge 2.0-enabled device using the TOPSwitch-JX switcher, CHY100D interface ICs, and an optocoupler feedback. The DER-381 can adjust the output voltage of the ac-dc wall charger to deliver increased power to the device’s battery through a standard USB cable.
The new reference design, called the DER-533 (see figure), is a USB-PD (USB Power Delivery) compliant ac-dc power converter also targeted at chargers for smart mobile devices. The DER-533 combines the EZ-PD CCG2 USB Type-C port controller from Cypress with Power Integrations’ InnoSwitch-CP off-line constant-voltage/constant-current (CV/CC) flyback switcher IC and Fluxlink technology. Fluxlink technology, already integrated in the InnoSwitch-CP family for some time, is a safety-isolated communication technology that eliminates the need for an optocoupler, which would otherwise cause restrictions on control-loop bandwidth and speed.
The EZ-PD CCG2 device on the power-adapter (PA) board supports USB Type-C and Power Delivery (PD) 2.0. It includes a 48-MHz ARM Cortex-M0 processor with 32-kB flash and 4-kB SRAM to enable firmware upgrades during product development. In addition, Power Integrations’ InnoSwitch-CP ac-dc controller handles ac-dc power conversion, overcurrent protection (OCP), and overvoltage protection (OVP). The controller supports a universal ac input supply, and manages the signaling between the device and power-conversion IC.
The DER-533 implements Profile 2 of the USB-PD standard, and is capable of 5-V/3-A and 9-V/2.2-A power delivery over a standard 3-A USB Type-C cable. According to the firms, constant power output from the switcher allows battery-operated devices to efficiently draw up to the maximum power of the charger at any selected output voltage, optimizing charge time and cost.
The reference design’s compliance with USB-PD is a key benefit, since the new power-delivery protocol is universal and thus can charge a wide range of consumer electronics products. Also, the new reversible Type-C connector could become the most widely adopted standard, because it can deliver up to 100 W and supports Display Port and Thunderbolt. The overall goal with the DER-533 is that it leads to lower charging costs and helps speed time to market for designers.