Uncovering the Magic: Noise Smart Watch Teardown

In this blog, I will do a teardown of Noise Smart Watch, their ColorFit Pulse Variant. I purchased this for my some time back and he used it every day since then. He recently saw me doing teardowns of other smart watch and ask if I want his Noise Smart watch which is not old, full of scratches, his condition was, in barter, he need a new smart watch from Noise, I had to agree 🙂

BTW: do you also see there is flood of smart watches in the market these days, a single company has so many variants, it becomes very confusing to pick one.

I already did teardowns of three Smart Watches, Mi Redmi Start Watch, BeatXP Smart Watch, Boat Smart Swatch, Noise is the fourth brand, let us what did they do differently.

Noise Swatch Watch ColorFit Pulse is a very basic version so I am not expecting anything high end inside.

Let us take it apart 😉

Front is a Color TFT Display with capacitive touch and the back side a charging connector, sensor for SPO2 and Heat beat and probably we should see an accelerometer sensor inside.

As with any smart watch, you need to heat the smart watch a little bit using hot air blower so that you can open it.

Once you open it, first thing you will see is a color TFT display.

You can see in the image below, Capacitive touch panel is connected to the display flex cable. The IC used is a typical capacitive touch panel controller IC with I2C interface, 6 pins.

Here is the closer look. You can see 6 pin capacitive touch panel cable is soldered on the display flex pcb.

LCD display connector is a 24-pin ZIF connector.

LCD flex cable is connected to the connector on the PCB.

once you remove the LCD cable, you get to see, on the left, you have a battery and on the right hand side is the main PCB.

Another connector you see below LCD connector is for sensor and switch flex PCB. I will show you that later.

Battery used is a Lithium battery single cell, 3.8V 210mAh 0.798Wh capacity directly soldered to the PCB with two wires.

other than two connectors, on the right hand side you see a XTR Chip, that is a Flash memory XT25F64B, it is a 64 Mbit Quad IO Serial NOR Flash.

Another small IC is there on the extreme left side of the PCB, it has a marking (hard to read) b930fp31, probably an accelerometer IC.

On the back side of the PCB, what you see is a large chip with QR code sticker, that’s the main processor from Realtek.

Right hand side of the processor, 40Mhz crystal is there with SMD marking T400.

On the PCB, 5V, GND charging pads are there, that where the sprint loaded pins on the enclosure get connected.

You can also see a vibration motor soldered directly on to the PCB.

There is another chip with SMD marking SX4, which is probably a battery charger IC.

The main processor or SoC is from Realtek, RTL8762C. It’s a BLUETOOTH LOW ENERGY 5 SOC.

The RTL8762CJ / RTL8762CJF / RTL8762CK / RTL8762CKF (referred to as the RTL8762C) is an ultra-low-power system on-chip solution for Bluetooth 5.0 low energy applications that combines the excellent performance of a leading RF transceiver with a low-power ARM Cortex-M4F and rich powerful supporting features and peripherals.

The RTL8762C supports an analog MIC interface that integrates a sigma-delta ADC, programmable gain amplifier, 5-Band equalizer and microphone bias circuit for voice command application.

The RTL8762C embeds IR transceiver, hardware key-scan, and Quad-decoder on a single IC, and is provided in a QFN package.

SoC has the following spec

• ARM Cortex-M4 with floating-point unit (Maximum 40MHz)
• Serial flash controller (One and Qual-bits mode) with 16kB 4-way cache.
• Total 160kB SRAM
• 4Kbits eFUSE for manufacturer use
• Supports AES128/192/256 encrypt/decrypt engine
• Embedded 2Mbits flash (RTL8762CKF/RTL8762CJF)

Bluetooth chip antenna is used on the PCB, see where BT silkscreen is there.

If you further remove the PCB, what you will see is a black color Flex PCB which has heartbeat and SPO2 sensor, front end IC and LEDs. The sensor Analog front end IC is HX3690Q

HX3690Q is an ultra-low power, high performance optical sensor with I2C interface for Wearable, Heart-Rate Monitor and Bio-sensor. HX3690Qintegrates a transmitter and a receiver. The receiver has an offset IDAC and a high-resolution ADC.

The transmitter has three LED driver ports sharing a 8bit current driver. Both transmitting and receiving path have very high dynamic range, which is desirable to process small PPG signals.

Same flex PCB also connects to the switch which is on the right side of the smart watch.

these are all the part of the Noise Smart Watch (ColorFit Pulse)

I hope you found this teardown interesting and learned something new.

I am always interested to know what other teardown you would be interested in, please do share in the comments below.

I will publish a new blog very soon.

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