ZHCSGV1C June 2017 – March 2018 TPS25740B
PRODUCTION DATA.
In this system design example, the PSEL pin is configured such that P(SEL) = 36 W, and 5 V, 9 V, 12 V are offered at a maximum of 3 A while 15 V is offered at a maximum of 2.4A. The over-current protection (OCP) trip point is set just above 3 A.
The ENSRC pin from one TPS25740B is attached to the PCTRL pin on the other TPS25740B. When one port is not active (no UFP attached through the receptacle) its ENSRC pin is left high-z so the PCTRL pin on the other port is pulled high. This allows the adaptor to provide up to the full 36 W on a single port if a single UFP is attached. If two UFP’s are attached (one to each port) then each port only offers current that would reach a maximum of 18 W. So each port is allocated half of the overall power when each port has a UFP attached.