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TPS254900A-Q1 Datasheet(PDF) 21 Page - Texas Instruments |
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TPS254900A-Q1 Datasheet(HTML) 21 Page - Texas Instruments |
21 / 39 page ![]() IN OUT DP_IN DM_IN ILIM_LO ILIM_HI GND CTL1 CTL2 EN TPS254900A-Q1 Port 1 100 kW 100 kW EN1 FAULT1 USB Charging Port 1 5 V FAULT STATUS IN OUT DP_IN DM_IN ILIM_LO ILIM_HI GND CTL1 CTL2 EN TPS254900A-Q1 Port 1 EN2 FAULT2 USB Charging Port 1 FAULT STATUS Copyright © 2017, Texas Instruments Incorporated 21 TPS254900A-Q1 www.ti.com SLUSCU5A – NOVEMBER 2017 – REVISED JANUARY 2018 Product Folder Links: TPS254900A-Q1 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated 8.3.6.3 Implementing PPM in a System With Two Charging Ports (CDP and SDP1) Figure 39 shows the implementation of the two charging ports with data communication, each with a TPS254900A-Q1 device and configured in CDP mode. In this example, the 5-V power supply for the two charging ports is rated at less than 3.5 A. Both TPS254900A-Q1 devices have R(ILIM) chosen to correspond to the low (1-A) and high (2.4-A) current-limit setting for the port. In this implementation, the system can support only one of the two ports at 2.4-A charging current, whereas the other port is set to the SDP1 mode and IOS corresponds to 1 A. Figure 39. PPM Between CDP and SDP1 8.3.7 Overcurrent Protection When an overcurrent condition is detected, the device maintains a constant output current and reduces the output voltage accordingly. Two possible overload conditions can occur. In the first condition, the output is shorted before the device is enabled or before the application of V(IN). The TPS254900A-Q1 device senses the short and immediately switches into a constant-current output. In the second condition, a short or an overload occurs while the device is enabled. At the instant the overload occurs, high currents flow for 1 to 2 μs (typical) before the current-limit circuit reacts. The device operates in constant-current mode after the current-limit circuit has responded. Complete shutdown occurs only if the fault is present long enough to activate thermal limiting. The device remains off until the junction temperature cools approximately 20°C and then restarts. The device continues to cycle on and off until the overcurrent condition is removed. |
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