Using Cheap Asian Electronic Modules
By Jim Rowe
USB Power Delivery
Chargers
Left-to-right: the Comsol COWCC30WH, XY-PDS100 and Belkin F7U060AU
This article describes some low-cost modules that have appeared recently
to take advantage of the dramatic growth in USB capability, especially
in the area of power delivery (PD). This assortment includes PD chargers,
cables and cable adaptors, while a follow-up article will look at ‘trigger’ or
‘decoy’ modules, used to configure the chargers, plus USB-PD testers.
W
hen USB first appeared
in the late 1990s, it could provide just 5V of power at up to
100mA for a ‘low-power’ device, or up
to 500mA for a ‘high-power’ device,
such as a USB hard disk drive.
But as the data transfer capabilities of
USB were expanded via USB 2.0, USB
3.0 and finally USB-C, the power delivery capabilities were expanded as well.
USB 3.0 kept the 5V supply voltage
but raised the ‘high-power’ current
level to 900mA, allowing a downstream device to receive up to 4.5W
(rather than just 2.5W).
When the USB-PD (Power Delivery)
specification was finalised in 2012,
a device could receive 5V at up to
1.5A or 7.5W of power via a standard
Type-A to Type-B USB cable.
The smaller USB-C 24-pin connectors appeared in 2014, and when
the USB-PD specification was further
revised in 2014, 2016 and 2017, they
increased the power delivery voltage
and current levels as well.
Now devices can request power at
either 5V, 9V, 12V, 15V or 20V, and
can draw up to 5A – corresponding to
100W with a 20V supply. And since
the USB-PD 3.0 revision of 2017,
devices can also take advantage of the
programmable power supply (PPS)
protocol, which allows variation of
36
the supply voltage in 20mV steps.
This expands the possible USB-PD
applications dramatically, and that’s
why we’re seeing so many low-cost
modules designed to take advantage
of this increased flexibility.
How USB-PD works
The key idea to understand is that
USB-PD is made possible thanks to
extra contact pins in a USB-C connector. Specifically, the CC1 (A5) and CC2
(B5) pins, which are designated the
Configuration Channel (CC) pins. The
notional arrangement is shown in Fig.1.
Initially, a USB-PD-capable power
supply sets its VBUS output voltage
to 5V. It also ties each of the CC pins
of its output (downstream) USB-C
connector to a logic high level via a
pull-up resistor Rp, with the value of
Rp chosen according to the supply’s
current capacity.
Devices designed to receive their
power from the USB-C connector are
fitted with a pull-down resistor Rd
connected between one of the CC pins
and ground. The value of Rd is chosen
to indicate the current level wanted
by the device.
As a result, when a cable from the
device is plugged into the USB-C connector, the voltage drop on one of the
CC lines indicates to the host that:
A load or ‘sink’ device is connected
The orientation of the USB-C plug
in the connector
Current available from host supply.
There is then an exchange of data packets between the supply and the load/
sink via the CC line, using DC-coupled
Fig.1: the USB-PD system consists of five elements: a primary DC power source,
a USB-PD ‘manager’ with a downstream facing port (DFP), a USB-C cable, a
trigger circuit fitted with an upstream facing port (UFP) and finally, the power
‘sink’. The USB-PD manager element could be combined with the primary DC
source, and the trigger circuit may also be combined with the sink.
Practical Electronics | August | 2022
BMC (Biphase Mark Code) or Differential Manchester encoding. This allows
the load device to indicate the supply
voltage it wants, and then the supply
to change its output to the requested
level if it can do so.
As mentioned above, if the supply
supports the PPS protocol, the voltage
can be adjusted in 20mV increments.
This negotiation can only occur if
the load device is connected to the supply via a USB-C connector and matching cable. It won’t work if a Type-A
USB connector is used, because this
lacks any CC pins or cable lines.
The initial USB-PD Rev.1 specification of 2012 allowed a device connected to a host/power supply via USB
2.0/3.0 Type-A and Type-B connectors
to negotiate a higher voltage than 5V
(eg, 12V or 20V) using a binary FSK signal on the VBUS line. But this approach
was deprecated when USB-PD Rev.2.0
was released in 2014.
So most USB-PD power supplies
can only deliver 5V (or perhaps 12V)
via their USB Type-A downstream
port or ports.
Note that the USB-PD negotiation
protocol allows for power to be transferred in either direction – from host
to device or vice-versa. For example,
a laptop or tablet PC can get its battery recharged quickly from a USB-PD
power pack/charger by requesting that
the charging be done at 9V, 15V or 20V
instead of 5V.
The XY-PDS100 quick charger
This first module is a ‘fast charger’
that can be configured to give a range
of output voltages and currents using
the standard USB-PD protocol.
The XY-PDS100 comes in an
extruded aluminium case measuring
53 x 46 x 21mm. It is available from
several internet suppliers, including
Banggood, which at the time of writing
has it for £14 plus £2.50 for shipping.
As shown in the photos, the output end of the XY-PDS100 has a USB
Using USB-PD for fast charging
Even before the USB-PD specification
was released in 2012, various firms
associated with the burgeoning mobile phone market worked out ways
to use USB sockets for fast-charging
mobile phone batteries. Examples
are Qualcomm, which had developed
its Quick Charge (QC) protocol, Motorola with its TurboPower protocol
and Huawei with its SuperCharge
(SC) protocol.
Perhaps because of the widespread
application of these protocols, the
various revisions of USB-PD gradually
embodied them. As a result, when the
USB-PD revision 3.0 was released in
2017, including PPS (Programmable
Power Supply), it essentially incorporated just about all of the earlier fastcharging protocols.
So that’s why the specifications of
most of the USB-PD trigger modules
and fast chargers will claim compatibility with a list of protocols such as
PD 2.0, PD 3.0, Qualcomm QC3.0 and
QC4+, Huawei SCP/FCP, Apple 2.4A,
Samsung AFC, MediaTek PE2.0 and
PE3.0, Oppo’s VOOC and so on.
Type-A socket and a USB-C socket,
plus a 3-digit 7-segment LED display
(with 6.5mm-high digits) and three
indicator LEDs. One lights when the
output voltage is displayed, one when
it’s showing the current being drawn
from the USB-C socket, and the third
when showing the current drawn from
the Type-A socket.
At the ‘input’ end, there are two
sockets. One is a small concentric
DC socket designed to accept 12-28V
DC from a mains power supply, and
the other a USB-C socket marked
‘Input-PD’. On the underside of the
case, the latter input has the legend
‘PD Recommended 87W’, but it seems
to be simply an alternative DC input.
Essentially, what the XY-PDS100
does is convert a no-frills power supply with an output of 12-28V DC into
a ‘smart’ USB-PD battery charger or
power source, which can respond to
the negotiation from a trigger unit to
provide one of the standard charging
voltage and current profiles.
So it’s basically a programmable
switch-mode step-down DC-to-DC converter, which can provide up to 100W
of power at voltages between 5V and
20V from the USB-C output, or up to
36W of power at voltages between 5V
and 12V from the USB Type-A output.
And it even includes a three-digit LED
readout displaying the current output
voltage and current. Not bad for a very
compact little unit that costs less than
£20 delivered.
Because the XY-PDS100 is a stepdown converter, it needs to have a DC
input voltage at least 2V higher than
the highest output voltage that could
be requested. So if you only want a
maximum of 12V for charging via the
Type-A output, an input voltage of
14-15V would be fine. But for the full
range of voltages required for USB-PD
fast charging, the input voltage will
need to be at least 22-23V.
I was quite happy with the measured performance of the XY-PDS100.
It seems quite compatible with the PD
3.0 protocols, and also with the PPS
‘vernier adjustment’ protocol.
While the XY-PDS100 is a ‘USB-PD
Manager’ module, needing an external DC supply, the remaining devices
we’re going to look at combine both
functions, forming a complete USB-PD
power source.
I had some difficulty obtaining them,
though. I ordered a couple of units from
a Chinese supplier, but they didn’t
arrive, and I eventually discovered that
they were out of stock. So, I had to get
them from local suppliers, but they cost
significantly more than the units I had
ordered from China. (Note that for me,
The XY-PDS100 is shown at left connected to an XY-WPDT trigger unit.
This trigger unit helps to set the provided charging profile for the input
device by outputting a fixed voltage. At lower right is the rear of the XYPDS100; both these photos are shown at approximately life size.
Practical Electronics | August | 2022
37
Take care when buying USB-C cables and adaptors
Although you will find many low-cost
USB-C cables from vendors on the
internet, you need to be careful when
buying many of them. For example,
quite a few of the low-cost cables
are really only suitable for providing
power and battery charging, not transferring data, and especially not highspeed data transfer.
Apart from the lines involved in
power transfer (including the configuration channel lines), they might not
have any of the data transfer lines,
except perhaps those for USB 2.0
(D+ and D ).
This applies particularly for cables fitted with a Type-A plug at one
end and a USB-C plug at the other. In
fact, the presence of a Type-A plug
is a strong indication that a cable
is not suitable for high-speed data
transfer, and quite possibly only for
power transfer and charging. And the
power transfer/charging will only be
possible at 5V, since negotiation of a
higher supply voltage probably won’t
be possible.
This also applies to the many nominal USB-C adaptors. If these have
a USB Type-A plug or socket at one
end, that means they are probably
only suitable for use in power transfer
and charging, although they might be
fine for low-speed and full-speed USB
data transfer via the D+ and D– lines,
assuming those wires are even fitted.
Even if a low-cost cable has USB-C
connectors at both ends, that is no
guarantee that it is suitable for really
high-speed data transfer. This makes
it a bit risky buying these cables via
the Internet, because you can’t test
them before you buy them.
In fact, if you see one of these cables for less than , you can probably assume it’s only suitable for
power transfer and battery charging.
USB-C cables capable of being used
for really high-speed data transfer
are likely to cost significantly more
than that.
‘local’ means Australia, but I’m sure
you can get similar if not identical versions in your part of the world.)
provide any of the full five output voltages: 5V, 9V, 12V, 15V or 20V. As with
the Belkin unit, it could provide up to
3A at 5V or 9V, but at 12V, it could provide up to 2.5A. Then at 15V, it could
provide up to 2A, while at 20V, it could
provide up to 1.5A.
So it’s only a 30W power source for
three of the five selectable voltages.
Considering that its price is virtually
the same as the Belkin unit, the fact that
it provides a choice of the full five PD
voltages, and with a nearly consistent
power capability of 30W, makes it better value for money.
The range of voltages and currents
available from this type of charger
means that it could power a wide range
of devices, including those you might
build yourself.
If each of those devices contains circuitry to negotiate the current and voltage required, that means you could have
a small selection of power supplies to
power a wide range of devices.
So, in essence, these chargers could
be the new ‘multi-voltage plugpack’ we
all use in future.
The Belkin F7U060AU
27W power adaptor
This unit cost around £20 from JB Hi-Fi
(www.jbhifi.com.au). It measures just
51 x 60 x 31mm and weighs 50g. The
unit is pictured in the rightmost photo
at the start of this article; it has a twopin mains plug on one end and a USB-C
socket on the other end. That’s it – it’s
just an elongated version of the familiar
USB plugpack. The inscription on the
plug end advises that it was designed
in California and assembled in China.
When I tried it out with a couple of different trigger units, I found that although
it would register as a PD 3.0 device, it
would only provide a choice of three
output voltages: 5V, 9V or 12V. The two
lower voltage settings can provide up to
3A of current, while the 12V setting can
provide up to 2.25A.
So the power rating of 27W only
applies when the unit provides 9V or
12V; when it’s providing 5V, it is really
a 15W source. Of course, this would be
fine if you only wanted up to 12V and
15-27W.
The Comsol COWCC30WH
30W wall charger
This unit also cost £20 from Officeworks (www.officeworks.com.au/
shop/). It measures 44 x 64 x 40mm, and
weighs 80g. As you can see from the
leftmost photo at the start of this article, it’s very similar to the Belkin unit,
with a two-pin mains plug at one end
and a USB-C socket at the other end.
The inscription on its plug end simply
says ‘Made in China’.
When I checked this unit with a couple of different trigger units, it only registered as a PD 2.0 device, but could
38
The ALOGIC WCG1X65-ANZ
65W wall charger
The third USB-PD wall charger I
bought is the ALOGIC WCG1X65,
which again is very similar in size to
USB-C breakout boards
Because of the possible problems associated with USB-C cables, you might
be interested in the low-cost ‘breakout’ module or test board shown in
the photo below. It is available from
internet suppliers like Banggood for
only US$2.10 for a single, US$4.80 for
a pack of five or US .00 for a pack
of ten (all plus shipping, of US$3.30
in each case).
This module’s PCB measures only
25 x 40mm and has a USB-C socket
mounted at the centre of one of the
40mm sides. All 24 of the socket’s
connections are brought out to two
rows of 12 solder pads at the opposite
edge of the PCB, with one row (A1-12)
on the top and the other (B1-12) underneath. The socket’s metal frame is
also brought out to a further ‘G’ pad
on each side of the PCB.
A pair of these ‘breakout’ boards
make it easy to test all of the lines
and connections in a USB-C cable. I
bought a pack of five, but wasn’t too
impressed with the soldering for the
24 very closely spaced pins of the
sockets; one of them seemed to have
a dry joint or two.
Since it would not be easy to repair
these joints manually because of the
very close spacing (about 0.5mm), I
decided that the board concerned was
throw-away material – so be warned!
In my next article, we’ll take a look
at some of the low-cost USB PD ‘trigger’ modules that can be used to set
the output voltage and current of
USB power supplies, like the ones described here.
Practical Electronics | August | 2022
the Belkin and Comsol units. It’s slightly smaller, measuring 55 x 60 x 35mm, and weighs close to 95g. This unit also
came from JB Hi-Fi, at a cost of around £40 plus delivery.
While it is almost twice the price of the other wall chargers, it boasts over twice the power capability at 65W. It
comes with a 2m-long USB-C charging cable and a tiny (90
x 110mm) four-page quick start guide. It also features a white
LED power indicator, just below the USB-C output socket.
When I checked this unit with the same trigger units as
before, it registered as a PD 3.0 device and could easily be
programmed to give any of the five standard PD voltages:
5V, 9V, 12V, 15V or 20V. And it can provide up to 3A at any
of the four lower voltages, or up to 3.25A at 20V, which is
pretty impressive considering its compact size and weight.
The makers claim that this is a result of using ‘the latest GaN charging technology’. Presumably, they are taking advantage of the ability of transistors and diodes using
gallium nitride (GaN) substrates to operate at much higher
voltages and with higher efficiency.
So if you need a USB-PD wall charger capable of supplying up to 65W of power at any of the five PD 3.0 voltage levels, the ALOGIC WCG1X65-ANZ would be the best
choice despite its significantly higher cost.
Note that one of the devices that I tried and failed to
source from China was the Bakeey HC-652CA 65W wall
charger, which would probably also be a good choice, if
and when it becomes available.
Useful links
USB-C
USB-PD
The ALOGIC WCG1X65-ANZ 65W wall charger, shown
enlarged for clarity. It registers as a PD 3.0 compliant device,
and therefore can provide the standard voltages of 5V, 9V,
12V, 15V and 20V at 3A (or 3.25A for 20V). As the output
power increases, these chargers can become quite costly.
Quick Charge
Gallium nitride
https://w.wiki/nto
https://w.wiki/34dT
https://bit.ly/pe-aug22-usbc
https://w.wiki/34dU
https://w.wiki/34dV
Reproduced by arrangement with
SILICON CHIP magazine 2022.
www.siliconchip.com.au
STEWART OF READING
17A King Street, Mortimer, near Reading, RG7 3RS
Telephone: 0118 933 1111 Fax: 0118 933 2375
USED ELECTRONIC TEST EQUIPMENT
Check website www.stewart-of-reading.co.uk
Fluke/Philips PM3092 Oscilloscope
2+2 Channel 200MHz Delay TB,
Autoset etc – £250
LAMBDA GENESYS
LAMBDA GENESYS
IFR 2025
IFR 2948B
IFR 6843
R&S APN62
Agilent 8712ET
HP8903A/B
HP8757D
HP3325A
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HP6622A
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HP6644A
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Marconi 2022E
Marconi 2024
Marconi 2030
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PSU GEN100-15 100V 15A Boxed As New
£400
PSU GEN50-30 50V 30A
£400
Signal Generator 9kHz – 2.51GHz Opt 04/11
£900
Communication Service Monitor Opts 03/25 Avionics
POA
Microwave Systems Analyser 10MHz – 20GHz
POA
Syn Function Generator 1Hz – 260kHz
£295
RF Network Analyser 300kHz – 1300MHz
POA
Audio Analyser
£750 – £950
Scaler Network Analyser
POA
Synthesised Function Generator
£195
Dynamic Signal Analyser
£650
PSU 0-60V 0-50A 1000W
£750
PSU 0-20V 4A Twice or 0-50V 2A Twice
£350
PSU 4 Outputs
£400
PSU 0-20V 0-5A
£195
PSU 0-60V 3.5A
£400
PSU 0-60V 0-9A
£500
Synthesised Sweep Generator 10MHz – 20GHz
£2,000
Synthesised Sweeper 10MHz – 26.5 GHz
POA
Synthesised Sweeper 2 – 20GHz
POA
Power Sensor 0.01-18GHz 3nW-10µ W
£75
Spectrum Analyser Synthesised 30Hz – 2.9GHz
£1,750
Spectrum Analyser Synthesised 9kHz – 22GHz
£2,250
Spectrum Analsyer 100Hz – 22GHz
£1,200
RF Generator 10kHz – 1280MHz
£750
Synthesised AM/FM Signal Generator 10kHz – 1.01GHz
£325
Synthesised Signal Generator 9kHz – 2.4GHz
£800
Synthesised Signal Generator 10kHz – 1.35GHz
£750
Signal Generator 9kHz – 1.2GHz
£700
HP33120A
HP53131A
HP53131A
Audio Precision
Datron 4708
Druck DPI 515
Datron 1081
HP/Agilent HP 34401A Digital
Multimeter 6½ Digit £325 – £375
HP 54600B Oscilloscope
Analogue/Digital Dual Trace 100MHz
Only £75, with accessories £125
(ALL PRICES PLUS CARRIAGE & VAT)
Please check availability before ordering or calling in
Keithley 228
Time 9818
Practical Electronics | August | 2022
Marconi 2305
Marconi 2440
Marconi 2945/A/B
Marconi 2955
Marconi 2955A
Marconi 2955B
Marconi 6200
Marconi 6200A
Marconi 6200B
Marconi 6960B
Tektronix TDS3052B
Tektronix TDS3032
Tektronix TDS3012
Tektronix 2430A
Tektronix 2465B
Farnell AP60/50
Farnell XA35/2T
Farnell AP100-90
Farnell LF1
Racal 1991
Racal 2101
Racal 9300
Racal 9300B
Solartron 7150/PLUS
Solatron 1253
Solartron SI 1255
Tasakago TM035-2
Thurlby PL320QMD
Thurlby TG210
Function Generator 100 microHz – 15MHz
Universal Counter 3GHz Boxed unused
Universal Counter 225MHz
SYS2712 Audio Analyser – in original box
Autocal Multifunction Standard
Pressure Calibrator/Controller
Autocal Standards Multimeter
o er
lifier
Voltage/Current Source
DC Current & Voltage Calibrator
Modulation Meter
£250
Counter 20GHz
£295
Communications Test Set Various Options
POA
Radio Communications Test Set
£595
Radio Communications Test Set
£725
Radio Communications Test Set
£800
Microwave Test Set
£1,500
Microwave Test Set 10MHz – 20GHz
£1,950
Microwave Test Set
£2,300
Power Meter with 6910 sensor
£295
Oscilloscope 500MHz 2.5GS/s
£1,250
Oscilloscope 300MHz 2.5GS/s
£995
Oscilloscope 2 Channel 100MHz 1.25GS/s
£450
Oscilloscope Dual Trace 150MHz 100MS/s
£350
Oscilloscope 4 Channel 400MHz
£600
PSU 0-60V 0-50A 1kW Switch Mode
£300
PSU 0-35V 0-2A Twice Digital
£75
Power Supply 100V 90A
£900
Sine/Sq Oscillator 10Hz – 1MHz
£45
Counter/Timer 160MHz 9 Digit
£150
Counter 20GHz LED
£295
True RMS Millivoltmeter 5Hz – 20MHz etc
£45
As 9300
£75
6½ Digit DMM True RMS IEEE
£65/£75
Gain Phase Analyser 1mHz – 20kHz
£600
HF Frequency Response Analyser
POA
PSU 0-35V 0-2A 2 Meters
£30
PSU 0-30V 0-2A Twice
£160 – £200
Function Generator 0.002-2MHz TTL etc Kenwood Badged
£65
d
£350
£600
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POA
POA
£400
POA
POA
POA
Marconi 2955B Radio
Communications Test Set – £800
39
