Introduction

Recently, we conducted a charging review of the IKEA SJÖMÄRKE wireless charger and found that it can draw nearly 15W but only provides a wireless output power of 5W. Although this may seem inefficient at first glance, it actually makes sense because its usage range is much larger than that of a normal wireless charger. And today, let's take it apart to examine its internal components and structure.

Product Appearance

The packaging box adopts a pure white design with the product name printed on the top left corner.

The usage range of 8-22mm (0.31-0.87 inches) is printed on the back.

It contains a power adapter, double-sided tapes, product manual and the wireless charging pad itself.

The power adapter is similar to the Apple 140W charger but with sharper edges.

All of the specs info is engraved on the side, although to be honest, the words are barely legible. Nevertheless, let's proceed. The model is ICPSW24-19-1, it can supports input of 100-240V~ 50/60Hz, 0.4A, and the output is 24V DC 0.8A Max 19W Max.

And it has passed multiple certifications.

The IKEA SJÖMÄRKE wireless charger is made of ABS and alloy materials with a fine-grain frosted process. It feels comfortable and smooth, and the built-in charging cable can prevent loss.

The black connector of the cable adopts a special dc barrel jack.

And the joint between the cable and wireless charging pad is reinforced with rubber sleeve.

Additionally, there is an LED indicator on the side that displays the device's work status. During normal charging, it will emit a steady white light.

The cross-shaped recessed area on the front of the IKEA SJÖMÄRKE wireless charger is the wireless charging area. This area can be used to charge mobile phones and earphones.

The back of the wireless charging pad features a metal cover module with a "concentric circle" design, which aids in heat dissipation during charging.

Model is E2018SJÖMÄRKE, it can supports input of 24V0.7A 16.8W, and the output is 5W Max.

There are four screw holes in each corner for users to use if they decide not to use double-sided tape.

The length of the IKEA SJÖMÄRKE wireless charger is about 173mm (6.81 inches).

The width is about 86mm (3.39 inches).

And the height is about 15mm (0.61 inches).

The length of the charging cable is about 188cm (6.17 ft).

This is how it looks like on my hand.

The weight of the wireless charging pad is about 287g (10.12 oz).

And the total weight is about 383g (13.51 oz).

After connecting the power supply, when the device is not charging, the power consumption of the IKEA SJÖMÄRKE wireless charger is 0.68W as measured by the PR10 power meter.

Then, we put a white foam between the phone and the charging pad to simulate the real world usage range of 8-22mm (0.31-0.87 inches) mentioned above.

When charged with an iPhone 14 Pro Max, the power meter shows a reading of 15.95W.

Teardown

Next, let's take apart the device and examine its internal components and structure, to see if we can find out how this charger achieved such a wide usage range.

Remove all the fixing screws.

The wireless charging pad can be divided into two oppositing part - the PCBA module on the left and the wireless charging coil on the right.

The PCBA module is also fixed with screws.

The master control chip of wireless charging, two half-bridge drivers, four wireless charging MOSFETs, operational amplifier chip, buck circuit and detection circuit are on the front of the PCBA module.

And there are no components on the back.

The charging cable is reinforced with potting compound at the output end.

This SMD inductor marked with 142 is used for input filtering.

These threee MLCC capacitors are connected in parallel for filtering.

The buck chip that powers the master control chip is from MPS, model MP9841, which is actually a synchronous buck converter with integrated MOSFET. 36V 1A.

The 22μH buck inductor works with the MP9841.

The master control chip marked with 65IK X SC A U7H2145 is from Infineon.

The component located next to it is the external active crystal oscillator.

The LDO that powers the master control chip is from Infineon and is marked with E3. The model is IFX20002MBV33. It can provide a fixed output of 3.3V and supports enable control.

The quad op amp is from STMicroelectronics, model TSV994, which support rail-to-rail input/output.

The 74HC4051 analog switch is used to detect the distance of the capacitors.

And those two dual op amps are from TI and are marked with 1MAX. Model is LMV358A. They support low voltage rail-to-rail output.

A dual N/P-channel MOSFET marked with 49K is used for power supply control.

The wireless charging full-bridge is composed of two half-bridges, and between the four MOSFETs are six parallel MLCC filter capacitors.

The half-bridge driver for the MOSFETs is from Infineon EiceDRIVER series and is marked with EDrWCDS006. The model is WCDSC006. 60V 2A/4A.

The MOSFET is from Infineon, model BSC035N04LS G, which adopts SuperSO8 package. 40V 3.5mΩ.

And all six MLCC capacitors adopt 1210 package.

These seven resonant capacitors connected in parallel adopt 1206 package.

The wireless charging coil is covered with capacitive sensor pad, which are used to detect the distance from the mobile phone to the wireless charger.

After removing the sensor pad, we can see a large charging coil underneath it. This is likely the main reason for the charger's impressive usage range.

And the capacitive sensor pad is connected to the PCB with this flat cable.

The NTC thermistor that detects the temperature of the wireless charger is connected to the PCB by two red wires, and they are reinforced with potting compound.

Uncover the coil, and the magnetic isolation sheet is pasted on the bottom with double-sided tape.

The isolation sheet is fixed in place by this square hole in the middle.

One last look at all the components of this IKEA SJÖMÄRKE wireless charger.

Summary of ChargerLAB

The IKEA SJÖMÄRKE wireless charger can be easily attached to the underside of a desk or other piece of furniture using either double-sided tape or screws, allowing the traditional wireless charging pad to be hidden from view and giving a sleek, seamless appearance to your house. This particular wireless charger comes with a specialized power adapter and a 188cm (6.17 ft) charging cable, perfect for daily use. Additionally, it boasts an impressive 8-22mm (0.31-0.87 inches) usage range, making it capable of accommodating a wide range of table thicknesses.

After taking it apart, ChargerLAB discovered that this wireless charger utilizes components from highly-regarded semiconductor companies such as STMicroelectronics, Texas Instruments, and Monolithic Power Systems. Furthermore, it comes equipped with a generously-sized charging coil, which is considered to be the main contributing factor to its remarkable usage range.

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