The Ventev TSW08 AC Charger Offers Up to 18W Output But Has Many USB Power Delivery Compliance Issues

The TSW08 AC Charger is one of the many compact AC wall chargers sold by Ventev supporting USB Power Delivery charging through USB Type-C. By supporting standard USB Power Delivery profiles of 15 watts (5 volts @ 3 amps) and 18 watts (9 volts @ 2 amps), the charger can sufficiently supply power to most mobile phones sold today such as the Apple iPhone XS Max or Android phones like the Google Pixel 3 XL and the Samsung Galaxy S10 Series, as well as providing decently fast charging to tablets like the Apple 11-inch iPad Pro (2018). Just make sure to use the Apple USB-C to Lightning Cable if you need to charge your iPhone.

The Ventev TSW08 AC Charger comes with a single USB Type-C port for charging out and foldable AC prongs for plugging into a AC wall socket.

Using the USB Power Test App from Granite River Labs with the Granite River Labs USB Power Delivery Compliance C2 Tester, we performed the following tests for the Ventev TSW08 AC Charger.

The USB Power Test App first negotiates a power contract for every PDO supported by the Ventev charger, and increases the load gradually to find the threshold where over current protection (OCP) kicks in and voltage and current start to drop for safety reasons. However the charger is not able to recover from 5V PDO OCP where the charger was observed to drop VBUS voltage to 5V when reaching 9V PDO OCP without dropping current or renegotiating PD contract.

The USB Power Test App reports out all the PDO's supported by the Ventev charger and their OCP thresholds. The OCP thresholds above the maximum current levels for this charger are very high which should just be around 10-20% for best practices.

PDO	OCP (A)	%OCP
PDO#1 Fixed: 5V 3A	3.94	131.3%
PDO#2 Fixed: 9V 2A	3.94	197.1%

The USB Power Test App from Granite River Labs then takes this data to produce an I-V curve which graphically shows the relationship between voltage and current for each PDO. We can observe after the current increases beyond the 5V PDO OCP threshold, the voltage just drops to 5V from 9V PDO OCP threshold without dropping current.

Using the USB Power Delivery Compliance C2 Tester from Granite River Labs to run just a subset of the full USB Power Delivery compliance test suite, compliance failures were mostly observed for the Ventev TSW08 AC Charger.

USB-IF High Level Mapping Summary

Sl No	Test Category	Test Group Description	Test Result
1	PHY_PRIMARY_TX	BMC Physical Layer Transmitter	FAIL
2	PHY_PRIMARY_RX	BMC Physical Layer Receiver	FAIL
3	PHY_PRIMARY_MISC	BMC Physical Layer Miscellaneous	FAIL
5	POWER_PRIMARY	Power Source/Sink Primary	PASS

Result Summary

Sl No	Test ID	Test Name	Test Result
1	TDA.2.1.1.1	TDA.2.1.1.1 BMC PHY TX EYE	FAIL
2	TDA.2.1.1.2	TDA.2.1.1.2 BMC PHY TX BIT	PASS
3	TDA.2.1.2.2	TDA.2.1.2.2 BMC PHY RX INT REJ	FAIL
4	TDA.2.1.2.1	TDA.2.1.2.1 BMC PHY RX BUSIDL	PASS
5	TDA.2.1.3.1	TDA.2.1.3.1 BMC PHY TERM	PASS
6	TDA.2.1.3.2	TDA.2.1.3.2 BMC PHY MSG	FAIL
7	TDA.2.2.1	TDA.2.2.1 BMC PROT SEQ GETCAPS	PASS
8	TDA.2.2.2.1	TDA.2.2.2.1 BMC PROT SEQ CHKCAP P PC	FAIL
9	TDA.2.2.2.2	TDA.2.2.2.2 BMC PROT SEQ CHKCAP NOMARK P PC	PASS
15	TDA.2.2.9	TDA.2.2.9 BMC PROT GSC REC	PASS
16	TDA.2.3.1.1	TDA.2.3.1.1 POW SRC LOAD P PC	PASS
17	TDA.2.3.2.1	TDA.2.3.2.1 POW SRC TRANS P PC	PASS

BMC Eye Diagram