Apple’s First USB Type-C Power Adapter
The two standards of Type-C power charging are Google Universal Type-C Charger 60W and the Apple 29W USB Type-C Power Adapter which were the first two USB Type-C chargers made available in the market respectively.
Apple's USB Type-C Power Adapter, the 29W USB-C Power Adapter, provides 29.6 watts (14.8 volts at 2 amps) or 12.5 watts (5.2 volts at 2.4 amps). It's a lot smaller than the Google Universal Type-C Charger 60W which provides 15, 36, or 60 watts.
I purchased the Apple 29W USB-C Power Adapter at the Apple Store in Westfield Valley Fair Mall in Santa Clara, California.
You'll want to only use Apple's USB Type-C Power Adapter with the Apple MacBook (Early 2015).
To look at the Apple 29W USB-C Power Adapter's support of power, we used the USB Power Test App from Granite River Labs with the Granite River Labs USB Power Delivery Compliance C2 Tester to produce the following test results.
The USB Power Test App first negotiates a power contract for every PDO supported by the Apple 29W USB-C Power 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 Apple charger and their OCP thresholds.
|PDO#1 Fixed: 5V 2.4A|
|PDO#2 Fixed: 14.8V 2A|
The USB Power Test App takes this data to produce an I-V curve which graphically shows the relationship between voltage and current for each PDO. We can observe as the current increases beyond the OCP threshold, the voltage immediately shuts off.
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.
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, unfortunately all compliance failures were observed for the Apple 29W USB-C Power Adapter so just be careful when using this charger.
USB-IF High Level Mapping Summary
Test Group Description
BMC Physical Layer Receiver
BMC Physical Layer Miscellaneous
Protocol Specific Primary
Power Source/Sink Primary
TDA.220.127.116.11 BMC PHY RX INT REJ
TDA.18.104.22.168 BMC PHY RX BUSIDL
TDA.22.214.171.124 BMC PHY TERM
TDA.126.96.36.199 BMC PHY MSG
TDA.2.2.1 BMC PROT SEQ GETCAPS
TDA.188.8.131.52 BMC PROT SEQ CHKCAP P PC
TDA.184.108.40.206 BMC PROT SEQ CHKCAP NOMARK P PC
TDA.2.2.7 BMC PROT BIST NOT 5V SRC
TDA.2.2.9 BMC PROT GSC REC
TDA.220.127.116.11 POW SRC TRANS P PC