Read Sony CPD-G420 / CPD-G420S / CPD-G520 / GDM-F520 Service Manual online
CR1 chassis (E)
18
7-1-2. Operation of Hub
There are two types in the hub, a bus-powered type where the power supplied from the USB cable is divided as it is, then supplied, and
a self-powered type that has an individual power in it. This set is a self-powered type. The self-powered type can supply 0.5A current
to each divided output (called downstream).
The standby about 6.5V is supplied to the CN2601, and it is regulated to 3.3V by the IC2601, and supplied to the IC2901.
The 6.5V power is regulated to 5V through IC2602, then supplied to the V Bus (5V) of downstream ports. IC2602 have the overcurrent
protective function for each downstream and they reduce the current when it reached about 2A. The IC2602 monitor the relation
between input voltage and output voltage of each regulator, and when output is low though input is normal, they judge this condition as
overcurrent, then give notice to the IC2901.
The IC2901 is the micro controller which makes makes USB communication, controls the hub, and drives the downstream, and various
settings and status sequence controls.
If an overcurrent signal is input to the IC2901 pin 31, 32, 35 and 36 the IC2902 places the pin 10, 11, 12 and 13 in high status to turn
off each output of overcurrent parts of IC2602.
Click on the first or last page to see other CPD-G420 / CPD-G420S / CPD-G520 / GDM-F520 service manuals if exist.