unknown chip in power supply section of dsl router

[jpdoe]

I'm trying to figure out how does a dsl router power section works.
It gets 12v DC from a wall wart, which gives about 17v when unloaded. When it's connected to the router PCB, there's almost 15v on the connector.
The next recognizable device is a 5v voltage regulator (ST 78M05), which seems to get a bit more than 12v as power input. In the same area there's an 8 pin smt device labeled as follows:
ST 063ec
9424
I can't figure out what it does. There's bobbins and electrolytic capacitors in the area, so I thought it was a PWM controller, but when I saw that what I confused initially with a power transistor was actually a voltage regulator.

[Wizard]

Re: unknown chip in power supply section of dsl router

This is chopper regulator through this bobbin (coil). Measure the output on other side of coil away from chopper to the ground with voltmeter. The capacitors smooths out the ripple that PWM pulses creates via this coil.

Cheers, Wizard

[Krankshaft]

Re: unknown chip in power supply section of dsl router

The newer routers seem to be using switching regulators rather than the conventional linear regulators.

These regulators (which are basically SMPS DC - DC converters on a compact IC). Emit much less heat that means smaller heatsinks and less heat inside the device.

The amount of external components they need is minimal too since most of the circuit is contained within the IC.

I think I will start to mock up some circuits with these soon.

[PCBONEZ]

Re: unknown chip in power supply section of dsl router

This it?

[jpdoe]

Re: unknown chip in power supply section of dsl router

Thanks for your answers.
PCbonez is right. That's exactly the part I was talking about.

/Out of topic begin/
The modem router in question is an Aztech DSL 305eu, based on the conexant roadrunner chip, 2MB flashrom and 8MB RAM. This configuration used to be quite popular here before they installed ADSL2 DSLAMs.
With the right firmware, it's quite stable. If bricked, it can be brought back to life with a simple procedure (reflashing through usb connection), and the firmware update involves no danger of bricking the device.
/Out of topic end/