USB-C Testing Circuit Using Configuration Channel Pin
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Solution Overview
Problem
Existing USB-C compliance testing requires additional pins for the TD 4.1.2 test item, increasing the cost and complexity of USB designs, especially in multi-port configurations.
Innovation Solution
A testing circuit that utilizes the configuration channel pin and ground pin of the USB-C to execute the compliance test without the need for additional pins, employing a controller, switches, pull-down resistor, and gating pull-up resistor to manage resistance values based on power receiving conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional pin is added to execute the TD 4.1.2 test item, then the compliance test can be performed, but the pin design cost and device complexity increase
Solution Approach 1:
The configuration channel pin PCC is made to serve dual purposes: both as a configuration channel for normal USB operation and as a test pin for executing the TD 4.1.2 compliance test. By controlling the switch Q1 based on power receiving conditions, the pin PCC dynamically switches between its normal configuration function and its test function, eliminating the need for a separate dedicated test pin.
Solution Approach 2:
The patent introduces dynamic control of the switch Q1 based on power receiving conditions. When power is received, the switch connects the configuration channel pin to ground for testing; when power is not received, the switch disconnects to maintain normal configuration channel operation. This dynamic switching enables the same pin to serve different functions at different times.
2Adaptability or versatility
If additional pins are added for multi-port compliance testing, then all ports can be tested, but the number of pins required increases linearly with the number of ports
Solution Approach 1:
The patent applies the multi-functionality principle to each port's configuration channel pin, allowing every port to perform self-testing through its own PCC pin without requiring shared test pins across ports. This enables N-port devices to be tested using only N configuration channel pins plus ground, rather than requiring (2N+1) pins.
Solution Approach 2:
Each port is enabled to test itself using its own configuration channel pin and ground pin, without requiring additional dedicated test pins or external testing equipment pins. The port's existing infrastructure (PCC and PGND) is sufficient for compliance testing when powered.
Data Source
AI summary
A testing circuit for testing a universal serial bus (USB) of an electronic device includes a controller, a first switch, a pull-down resistor, a gating pull-up resistor, and a second switch. The controller provides a control signal according to a power receiving condition of the electronic device. A control terminal of the first switch is coupled to the controller. The pull-down resistor is coupled between a configuration channel pin of the USB and a first terminal of the first switch. The gating pull-up resistor is coupled between the configuration channel pin and the control terminal of the first switch. A control terminal of the second switch is coupled to the controller. A first terminal of the second switch is coupled to a second terminal of the first switch and a ground pin of the USB. A second terminal of the second switch is coupled to a reference low voltage.