CHY100 from Power Integration: first component compatible with Qualcomm® Quick Charge 2.0September 13, 2013
In the previous post I introduced the Qualcomm® Quick Charge technology as competitor of the Usb Power Delivery in the rush to find faster and safer battery charge solutions. And we mentioned the CHY100 from Power Integration as the first component in the market compliant with this proprietary technology.
As in the Power Integration announcement: “…Used in combination with Power Integrations’ AC-DC switcher ICs, the CHY100 incorporates all the necessary elements required to add Quick Charge 2.0 functionality to AC-DC wall chargers. The CHY100 detects commands from a Quick Charge 2.0-enabled device, such as a cellphone handset, and adjusts the output of the AC-DC wall charger to enable increased power delivery to the device’s battery. …”
As the Quick Charge 2.0 specifications are not public, the datasheet of the CHY100 helps me to better understand the basic functionality, main features, flexibility and drawbacks of this technology.
The component is a physical interface able to detect a quick charger device and to negotiate the deliverable power. After the negotiation the devi
After startup, the CHY100 set the external feedback network to generate the standard 5V and short-circuits D+ and D-, to start the handshake as AC/DC adpater (DSP) with the powered device (PD) following the USB Battery Charging protocol. In this default configuration, if D+ remains lower than 0.35V for more than 1,25s, the device enters in Quick Charge mode.ce adjusts the external feedback network of the external ACDC converter to set the right voltage output. The CHY100 maintains the compliance with USB Battery Charging Specifications 1.2.
In Quick Charge mode the short circuit is promptly removed and a 19.53 kΩ pull-down resistor is connected to D-. After 1ms with D- below 0,325V, the CHY100 senses the D+ and D- Voltage levels imposed by the PD device and sets the feedback network according with the following table.
As far as I understand, the protocol is very easy and straightforward with very low system complexity. The major drawbacks I see are, in comparison with the much complex USB PD standard:
- Proprietary Standard.
- No USB communication during recharge. Strong limitation with dock stations
- usage limited to wall charger. Not applicable to USB hubs or other devices with double roles
Everything here is deducted indirectly from the CHY100 datasheet. I’ll accept comments, contributions and clarifications from readers.