A Closer Look at USB Power Delivery Capabilities of the Dell 130W USB Type-C AC Adapter

The Dell 130W USB Type-C AC Adapter ships with the Dell XPS 15 9575 (2-in-1) to provide USB Power Delivery 2.0 charging through the convertible PC's Thunderbolt 3 ports. With a max 130 watts output, the adapter can rapidly charge the Dell PC using the common USB Power Delivery profiles of 5 watts (5 volts @ 1 amps) and 130 watts (20 volts @ 6.5 amps).

The Dell 130W USB Type-C AC Adapter is also the first 130W USB Power Delivery based power adapter in the market supporting 20V, 6.5A which is more than what USB-IF specs allow at 20V, 5A. Dell is going beyond the specs and the connector thickness reflects a lot of current is going through it. 6.5A is only advertised when the adapter is used with a appropriate Dell product like the Dell XPS 15 9575 (2-in-1).

The Dell 130W USB Type-C AC Adapter is affixed with a USB Type-C to Type-C cable to connect to the Dell XPS 15 9575 (2-in-1) for charging. The adapter supports the common 100 to 240 V AC power requirement for own charging as well as supplying the most popular DC charging voltage levels- 5V and 20V.

The adapter comes with a separate AC power cord which you need to plug in to connect the charger to a AC wall outlet for charging.

Like most Dell power adapters, the Dell 130W USB Type-C AC Adapter is bigger and more bulky than many other wall chargers in the market.

To look at the Dell 130W USB Type-C AC Adapter's power capabilities, we used the USB Power Test App from Granite River Labs with the Granite River Labs USB Power Delivery Compliance C2 Tester to generate the following test results.

The USB Power Test App first negotiates a power contract for every PDO supported by the Dell 130W USB Type-C AC Adapter, 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. The USB Power Test App also reports out all the PDO's supported by the Dell adapter and their OCP thresholds. The USB Power Test App then takes this data to produce an I-V curve which graphically shows the relationship between voltage and current for each PDO.

PDO	OCP (A)	%OCP
PDO#1 Fixed: 5V 3A	3.58	119.2%

PDO	OCP (A)	%OCP
PDO#2 Fixed: 9V 3A	3.54	117.9%

PDO	OCP (A)	%OCP
PDO#3 Fixed: 15V 3A	3.51	117.1%

PDO	OCP (A)	%OCP
PDO#4 Fixed: 20V 3.25A	3.81	117.3%

The USB Power Test App can also use the Granite River Labs USB Power Delivery Compliance C2 Tester integrated with the GW Instek APS-7100 programmable AC power supply to compare the charger's power output vs power input so that power efficiency can be measured and compared to regulatory limits from United States of Energy (DOE) Level VI or European Union's CoC Tier 2 requirements. We can repeat the power efficiency tests for different PDO's, current load conditions, and different AC input ranges, allowing us to get a complete picture of power efficiency ranges across all different usage scenarios.

We also verified 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 for the Dell 130W USB Type-C AC Adapter as below. Note some compliance failures were observed.

DUT Information

Manufacturer	Dell
Model Number	130W PD AC Adapter
Serial Number	Comm

Test Information

Date and Time:

20181015_234806

Controller and Instrument Information

Parameter	Value
GRL USB-PD_C2 Serial No.	117.181.117.091.159.
GRL USB-PD Software Version	1.3.7.0
GRL USB-PD Firmware Version	1.3.7.0.0
GRL USB-PD Eload Firmware Version	9.4/9.4
Board Calibration	Calibration Success.
App Mode	COMMUNICATION_ENGINE_TESTS
Tx Mask	true
Rx Mask	false
RX mask Power selection	Neutral Power
Device Type	Provider Only
Cable IR drop Imp(R)	0
Cable Type.	USB-Type-C-Cable
COMMUNICATION_ENGINE_TESTS CTS Version	1.09
Noise Pattern Generation:	Two-Tone Noise
VIF info	*Since VIF was not loaded below test results are information Only.
Test cases Execution Time:	0h:11m:45s

USB-IF High Level Mapping Summary

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

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	PASS
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	PASS
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
7	TDA.2.2.1	TDA.2.2.1 BMC PROT SEQ GETCAPS	PASS
11	TDA.2.2.7	TDA.2.2.7 BMC PROT BIST NOT 5V SRC	PASS
13	TDA.2.2.9	TDA.2.2.9 BMC PROT GSC REC	PASS
14	TDA.2.3.2.1	TDA.2.3.2.1 POW SRC TRANS P PC	FAIL

BMC Eye Diagram

We can see in the below trace screenshots taken using the GRL-USB-PD C2 Compliance Test Solution App how the Dell 130W USB Type-C AC Adapter charged the Dell XPS 15 9575 (2-in-1) over USB Power Delivery. The Dell PC started off charging with the adapter at initial PDO of 90 watts (20 volts @ 4.5 amps) which then eventually reached up to 130 watts (20 volts @ 6.5 amps) PDO for maximum charging.

Here we can also see the load trace that shows the Dell 130W USB Type-C AC Adapter supporting different voltage and current levels for charging which we generated using the GRL-USB-PD C2 Compliance Test Solution App.