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Tenda S105 5-Port 10/100 Ethernet Switch

Top
Top

Here’s a tiny ethernet switch from the great fle market that is eBay – the Tenda S105. This unit has 5 ports, but only supports 10/100M. Still, for something so small it’s not bad.

Bottom
Bottom

Not much on the bottom, there’s a pair of screw hooks for mounting this to a surface.

Ports
Ports

The 5 ports on the front actually have the pins for the unused pairs of the ethernet cables removed – saving every penny here.

PCB Top
PCB Top

The casing just unclips, revealing the small PCB. Nothing much on the top, just the connectors, isolating transformers & the crystal for the switch IC.

PCB Bottom
PCB Bottom

The bottom of the PCB is a little more busy, mainly with decoupling components. There’s a 3.3v linear regulator to step down the 5v input for the switch IC.

Switch IC
Switch IC

The IC doing all the data switching is an IP175G 5-Port 10/100 Switch from IC+ Corp. No datasheet available for this, but it’s going to be a bog-standard switch.

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Topping NX1a Portable Headphone Amplifier

NX1a Amplifier
NX1a Amplifier

Time for another teardown! Here’s a pocket-sized headphone amplifier for use with mobile devices. This unit is powered by a built-in lithium cell, and can give some pretty impressive volume levels given it’s small size.

Audio Connections
Audio Connections

The 3.5mm audio input & output jacks are on the front of the unit, along with the relatively enormous volume knob & power switch. There’s a little blue LED under the switch that lets the user know when the power is on, but this is a very sedate LED, using very little power.

Gain & Charging
Gain & Charging

On the back is the High-Low gain switch, and the µUSB charging port. There’s another indicator LED to show that the internal cell is charging, in this case a red one.

PCB Top
PCB Top

Removing a couple of cap screws allows the internals to slide out of the extruded aluminium casing. Most of the internal space is taken up by the 1Ah lithium cell, here on the top of the PCB secured by some double-sided tape. The volume potentiometer is mounted on a small daughterboard at right angles to get it to fit into the small vertical space in the case.

PCB Rear
PCB Rear

The bottom of the PCB is equally as sparse – the only ICs being the main audio amp in the centre & the battery charger IC at the top.

Amplifier IC
Amplifier IC

The main audio amplifier is a TP9260, I couldn’t find a datasheet on this, so I’m unsure of what the specs are. The row of resistors above the IC are for the gain divider circuit. There’s also a pogo pin on the right that makes contact with the back panel of the case for grounding.

Battery Charger
Battery Charger

Battery charging is taken care of by a UN8HX 500mA linear charging IC, not much special here.

This little amplifier seems to be pretty well made, considering the price point. The only issue I’ve had so far is the audio cables act like antennas, and when in close proximity to a phone some signal gets picked up & blasted into the headphones as interference.

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IC Decap – Genesis Logic gmZAN3L XGA LCD Controller

Here’s a very common chip used in older LCD monitors. This converts the incoming VGA signal into LVDS for the panel itself.

gmZAN3 Die
gmZAN3 Die

The gmZAN3 is a graphics processing IC for Liquid Crystal Display (LCD) monitors at XGA resolution. It provides all key IC functions required for the highest quality LCD monitors. On-chip functions include
a high-speed triple-ADC and PLL, a high quality zoom and shrink scaling engine, an on-screen display (OSD) controller and digital color controls.