foreword
USB PD is currently the mainstream fast charging protocol. With the release of USB PD3.1, the transmission power can reach up to 240W. With the popularity of the USB Type-C interface, most electronic products begin to use the Type-C interface for power transmission. When mentioning the Type-C interface, it is often associated with USB PD fast charging. Among them, Type-C is a new interface specification, and USB PD is a fast charging protocol, because the Type-C interface has a dedicated communication line CC (channel configure) that can be used to transmit the USB PD protocol, so it is often used USB PD and Type-C are divided together, but there is an essential difference between the two.
It can be seen from the above figure that USB PD communication is the data interaction between Host (Source) and Power Brick (Sink).
1. When the Sink is connected (the host detects the access of the 5.1K pull-down resistor), the host (Source) will send the Source Cap (including the PDO that can provide the voltage range) within 100ms~200ms.
2. When the device receives the message from the host, it will reply Good CRC to respond, and reply Request (request the required voltage and current) within 24ms.
3. When the host receives the Request from the device, it will respond with Good CRC and check whether its own PDO supports the device Request. If it supports it, it will reply Accept within 24ms. If it does not support it, it will reply Reject.
4. When the device receives the Accept/Reject from the host, it will respond with a Good CRC.
5. If the host supports the device request, it will adjust the voltage within 450ms, send PS_RDY after the voltage adjustment is completed, and then wait for the device to reply Good CRC to respond.
2. Use steps
LDR6328S is a sink controller compatible with USB PD, QC and AFC protocols developed by Ledry Technology Co., Ltd.
The LDR6328S draws power from adapters supporting USB PD, QC and AFC protocols, and supplies power to the device. For example, the adapter can be configured to output
the required power to supply power to the wireless charger device. The LDR6328S is also compatible with conventional USB power adapters.
2. Features
◇ Adopt SOP-8 package
◇ Compatible with USB PD 3.0 specification, support USB PD 2.0
◇ Compatible with QC 3.0 specification, support QC 2.0
◇ Support AFC protocol
◇ Can trick PD, QC and AFC to output a fixed voltage.
◇ The default maximum output is 9V. If you have different power requirements, please contact us for customized design.
3. Application
◇ All small home appliances that require adapters (supporting USB PD, QC and AFC protocols) for fast charging and power supply.
Summarize
Although many electronic products currently use the Type-C interface, they do not have fast charging capabilities. The reason is that the electronic products lack a power receiving end (sink) protocol IC to negotiate PD with the power supply end (source). Moreover, many electronic devices still use charging interfaces such as DC, Micro, and Mini USB, which not only have slow charging efficiency and poor compatibility, but also have relatively single interface functions. Therefore, the PD protocol power receiving chip LDR6328 can be added on the basis of the Type-C interface, which not only frees consumer electronics products from the trouble of 5V low power consumption for a long time when charging. It also makes consumer electronic products such as wireless chargers, rechargeable shavers, and lithium battery electric tools get rid of the embarrassing situation of incompatibility of various chargers.