Liquid detection and corrosion mitigation
Methods, structures, and apparatus that are able to detect the presence of liquid, moisture, or other contaminants in or on a connector. Examples provide a connector having a dedicated liquid-detect contact that does not have a corresponding contact in a corresponding connector. Examples provide liquid-detect circuitry that can use the liquid-detect contact to determine the presence of a liquid on or in the connector and can perform self-diagnostic tests such as continuity checks and calibration.
1 . A connector comprising:
a tongue;
a plurality of contacts having contacting surfaces on the tongue, each of the plurality of contacts to form physical and electrical connections with a corresponding contact in a corresponding connector when the connector is mated with a corresponding connector;
a first contact to remain disconnected from any contact in the corresponding connector when the connector is mated with the corresponding connector;
a second contact to mate with a corresponding contact when the connector is mated with the corresponding connector, the second contact coupled to ground through a series combination of a switch and a resistor; and
a liquid-detect circuit coupled to the first contact and the second contact, wherein the liquid-detect circuit uses the first contact and the second contact to determine a presence of liquid on the tongue, and when liquid is detected on the tongue, the switch is opened and when liquid is not detected on the tongue, the switch is closed coupling the second contact to ground through the resistor.
2 . The connector of claim 1 wherein the first contact is a liquid-detect contact and the second contact is a connection detection contact.
3 . The connector of claim 2 wherein the liquid-detect contact is located on the tongue.
4 . The connector of claim 3 wherein the connection detection contact is located on the tongue.
5 . The connector of claim 4 wherein the resistor is connected directly to ground.
6 . The connector of claim 5 wherein the tongue is formed of a printed circuit board.
7 . The connector of claim 5 wherein the tongue is formed of plastic.
8 . The connector of claim 1 wherein the first contact is positioned between two contacts in the plurality of contacts.
9 . A connector comprising:
a tongue;
a plurality of contacts having contacting surfaces on the tongue, each of the plurality of contacts to form physical and electrical connections with a corresponding contact in a corresponding connector when the connector is mated with a corresponding connector;
a first contact to remain disconnected from any contact in the corresponding connector when the connector is mated with the corresponding connector;
a second contact to mate with a corresponding contact when the connector is mated with the corresponding connector; and
a liquid-detect circuit coupled to the first contact and the second contact, wherein the liquid-detect circuit provides a square-wave voltage pulse to a drive circuit having an output coupled to the first contact, measures an output voltage at the first contact, and measures a resulting current at the second contact.
10 . The connector of claim 9 wherein the liquid-detect circuit measures the resulting current at the second contact by converting the resulting current to a resulting voltage and measuring the resulting voltage.
11 . The connector of claim 10 wherein the liquid-detect circuit further determines an overshoot of the resulting current.
12 . The connector of claim 11 wherein the liquid-detect circuit further determines a rise time of the output voltage at the first contact.
13 . The connector of claim 12 wherein the liquid-detect circuit converts the resulting current to a resulting voltage using a transimpedance amplifier.
14 . The connector of claim 12 wherein the liquid-detect circuit further determines a presence of a liquid using the overshoot of the resulting current and the rise time of the resulting voltage.
15 . The connector of claim 9 wherein the liquid-detect circuit further determines a presence of a liquid using characteristics of the resulting current and characteristics of the output voltage.
16 . The connector of claim 9 wherein the drive circuit comprises an amplifier.
17 . A connector comprising:
a tongue having a top side;
a plurality of contacts having contacting surfaces on the top side of the tongue, each of the plurality of contacts to form physical and electrical connections with a corresponding contact in a corresponding connector when the connector is mated with a corresponding connector;
a first contact on the top side of the tongue;
a second contact on the top side of the tongue;
a third contact on the top side of the tongue;
a solder mask layer selectively formed on the top side of the tongue, wherein the solder mask layer is formed between the first contact and the second contact on the top side of the tongue and is absent between the second contact and the third contact on the top side of the tongue;
a ground pad positioned such that the plurality of contacts are between the ground pad and a leading edge of the tongue; and
a liquid-detect contact between the plurality of contacts and the ground pad.
18 . The connector of claim 17
wherein the solder mask layer is further formed between the plurality of contacts and the ground pad.
19 . The connector of claim 18 wherein the solder mask layer forms a raised portion between the first contact and the second contact.