Introduction
Recently, we received a GaN charger from Walmart’s Onn. Brand. This charger features three USB-C ports and one USB-A port. Each USB-C port supports 60W PD fast charging and is USB-IF PD certified. It can charge laptops and also supports a 20W+20W+20W output configuration, making it ideal for fast charging three iPhones simultaneously.
The USB-A port delivers 12W output independently, suitable for powering smaller devices like earbuds and smartwatches. Overall, this charger significantly improves charging efficiency. As a product from a globally recognized brand, it uses a full GaN power solution designed by iSmartWare. Let’s take a closer look inside.
Product Appearance

The front of the packaging displays the brand, design, product name, power rating, and certification marks.

The back shows the specifications.

The package contains only the charger.

The casing is made of flame-retardant PC material, with smooth, rounded corners and a matte finish, featuring a minimalist design.

The input side of the casing also has the specifications printed on it, with the Onn. Logo recessed in the center.

Model: WIAWHT36008513
Input: 100-240V\~50/60Hz 2.0A
Output:
USB-C1/C2/C3: 5V 3A, 9V 3A, 15V 3A, 20V 3A
USB-A: 5V 2.4A
C1 + C2/C3: 20W + 20W
C2 + C3: 20W + 20W
C1/C2/C3 + A: 60W + 12W
C1 + C2/C3 + A: 20W + 20W + 12W
C1/C2 + C3 + A: 20W + 20W + 12W
C1 + C2 + C3: 20W + 20W + 20W
C1 + C2 + C3 + A: 20W + 20W + 20W + 12W
The charger has passed ETL certification and Level VI energy efficiency certification.

It is equipped with foldable prongs.

The output side features three USB-C ports, one USB-A port, and an indicator light.

The length of the charger is about 60.07 mm (2.36 inches).

The width is about 50.27 mm (1.98 inches).

The thickness is about 38.12 mm (1.5 inches).

It is much smaller in size compared to the Apple 61W charger.

That's how big it is in the hand.

The weight is about 158 g (5.57 oz).

When powered on, the indicator light glows blue.

ChargerLAB POWER-Z KM003C shows that the USB-C1 supports PD3.0 and DCP charging protocols.

And it has four fixed PDOs of 5V3A, 9V3A, 15V3A, and 20V3A.

The USB-C2 port supports the same protocols as the USB-C1 port.

The PDO reports are also the same.

The USB-C3 port supports the same protocols as well.

The PDO reports are identical as well.

The USB-A supports DCP and Apple 2.4A charging protocols.
Teardown
Next, let's take it apart to see its internal components and structure.

Open the input-side casing, which is ultrasonically welded. The prongs are connected to the PCBA module via wires and secured with a black plastic plate and screws.

Remove the PCBA module. The length is about 56.14 mm (2.21 inches).

The width is about 45.36 mm (1.79 inches).

The thickness is about 33.07 mm (1.3 inches).

The PCBA module consists of multiple small PCBs. The gaps between the components and the small PCBs are filled with white adhesive for reinforcement.

The back of the module is covered by a copper heat sink, with a Mylar sheet between them for insulation.

After removing the heat sink, the PCB is found to have adhesive applied. Between the primary and secondary sides is a hollow filled with a Mylar sheet for isolation and insulation.

The adhesive was cleaned off. The transformer is located at the center of the front side.

On the back side, there are components including a bridge rectifier, master control chip, primary MOSFET, synchronous rectifiers, an optocoupler, and SMD Y capacitors.

Input side overview: the vertical PCB on the right features a filter inductor.

Remove the small PCB. On the front side, there is a time-delay fuse, a safety X2 capacitor, and two common mode chokes.

The back side has no components.

The time-delay fuse is from WalterFuse. 3.15A 250V.

This common mode choke is dual-wound and used to filter out EMI interference.

The other common mode choke is insulated with a heat-shrink tubing.

The safety X2 capacitor is from HEL. 0.22μF.

The ULBFR810 bridge rectifier is rated at 8A, 1000V, and uses a ULBF package.

Close-up of the filter inductor.

There are three high-voltage filtering electrolytic capacitors on the module.

All are manufactured by BERYL. These two are rated at 400V 47μF.

The other one is rated at 400V 33μF.

This side features the transformer and two solid capacitors.

The master control chip is the SW1106P from iSmartWare. It is a high-frequency quasi-resonant flyback controller that supports direct drive of enhancement-mode GaN FETs. It integrates a 700V high-voltage startup circuit and X-capacitor discharge function. With a built-in 6V GaN driver, it can directly drive GaN FETs.
The SW1106P operates in valley-switching mode with valley lock and includes frequency jitter to improve EMI performance. It supports burst mode and features a dual VDD supply design to reduce power loss under wide USB PD output voltage conditions.
It also integrates comprehensive protection features, including input overvoltage, supply overvoltage, output overvoltage, cycle-by-cycle current limiting, overload, output overcurrent, current sense resistor open/short protection, internal thermal shutdown, and support for external NTC for overtemperature protection.

The iSmartWare SW1106P uses an SSOP10 package and is designed for GaN fast charging, chargers, and switch-mode power supply applications. It expands iSmartWare’s product lineup in the fast-charging power supply sector.

The primary MOSFET is the Navitas NV6145C, rated for 700V with a 210mΩ Rds(on), and comes in a DPAK-4L package.

Close-up of the transformer.

The UPC1009G optocoupler is used for output voltage feedback.

The SMD Y capacitors are from TRX. Their compact size and light weight make them well-suited for high-density power applications such as GaN fast chargers. The part numbers are TMY1471K and TMY1102M, respectively.

The synchronous rectifier controller is the iSmartWare SW1608, a high-performance driver for secondary-side synchronous rectifiers in offline flyback converters. Packaged in SOT23-6, it supports 6V or 9V VCC power with self-supply capability, eliminating the need for an auxiliary winding and supporting a wide output voltage range. Used with MOSFETs to replace Schottky diodes, it significantly improves system efficiency.

The SW1608 supports a 600kHz switching frequency and is suitable for both High Side and Low Side configurations. It operates in multiple modes, including CCM, QR, and DCM. The chip features intelligent conduction detection to prevent false triggering caused by DCM ringing. Additionally, it offers ultra-low turn-off propagation delay and strong pull-down current capability, significantly reducing voltage stress on the rectifiers.

The two synchronous rectifiers, marked N10005D, use a PDFN 5×6 package.

The two solid capacitors for output filtering are also from BERYL, each rated at 25V 680μF.

All four USB sockets are mounted on separate small PCBs.

Remove all the small PCBs. On the front side of the three USB-C socket PCBs, each has a buck inductor and a secondary filtering solid capacitor.

The back side of each features a buck protocol chip, synchronous buck MOSFETs, and a VBUS MOSFET. All three USB-C PCBs share the same design and components, so only one will be detailed to save space.

The buck protocol chip is the iSmartWare SW3561H, which supports dual USB-C output. It integrates a high-efficiency synchronous buck converter capable of delivering up to 20V/5A and supports USB PD3.1 SPR. Built around an ARM Cortex-M0 core, it includes integrated Type-C logic and supports multiple fast-charging protocols such as PD3.1, QC, SCP, and UFCS, with customizable protocol support.
It enables dual USB-C path control with line loss compensation. When paired with two synchronous buck MOSFETs and corresponding VBUS MOSFETs, it can provide dual-port buck output. The internal buck converter operates at a default frequency of 180kHz, supports custom frequency settings, and can handle up to 100W output—ideal for compact designs. The chip includes comprehensive protection features such as over-temperature, input/output overvoltage and undervoltage, output overcurrent, and data pin overvoltage protection. It comes in a QFN-32 package.

Here is the information about iSmartWare SW3561H.

Both synchronous buck MOSFETs are iSmartWare SWT40N45, housed in a PDFN3030 package.

Close-up of the other one.

Close-up of the buck inductor.

The secondary buck solid capacitor is rated at 25V 150μF.

The output VBUS MOSFET is from ASDsemi, marked 30N40A. The full model is ASDM30N40AE-R, an N-channel MOSFET rated for 30V, housed in a PDFN3.3×3.3-8 package.

The USB-C socket uses through-hole soldering.

The front side of the USB-A socket PCB features a buck inductor and a solid capacitor.

The back side houses a synchronous buck converter.

The synchronous buck converter is the SouthChip SC8101. It supports a wide input voltage range of 5V to 32V and delivers up to 5V/5A output with high efficiency. The output voltage is adjustable, and it features precise output current limiting, entering constant current mode when the set limit is reached. The SC8101 integrates MOSFETs internally, minimizing the need for external components.

Here is the information about SouthChip SC8101.

Close-up of the paired 10μH buck inductor.

The solid capacitor for output filtering is from APAQ. 6.3V 220μF.

Close-up of the USB-A socket.

Well, those are all components of the Walmart Onn. 72W Multi-Port GaN Wall Charger.
Summary of ChargerLAB

Here is the component list of the Walmart Onn. 72W Multi-Port GaN Wall Charger for your convenience.
It features foldable prongs for easy storage and portability, with three USB-C ports and one USB-A port supporting 60W and 12W output, respectively, for a total output power of 72W. All three USB-C ports are USB-IF PD certified.
After taking it apart, we found that it uses the iSmartWare SW1106P + SW1608 high-frequency QR power solution, paired with a Navitas GaN component. Each of the three USB-C ports utilizes the SW3561H for secondary buck conversion and output control, while the USB-A port adopts a SouthChip SC8101 synchronous buck converter. It also uses capacitors from BERYL and APAQ for filtering. The module is built from multiple PCBs, with adhesive applied between gaps for reinforcement. As a product under Walmart’s Onn. Brand, the build quality and component selection are indeed impressive.
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