gl850g

Manufacturer Part Numbergl850g
DescriptionGl850g Usb 2.0 Low-power Hub Controller
ManufacturerGenesys Logic
gl850g datasheet
 
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V
V
(External 5V)
(External 5V)
BUS
BUS
GL850G internally contains a power on reset circuit as depicted in the picture above
Internal reset
External reset
To fully control the reset process of GL850G, we suggest the reset time applied in the external reset circuit
should longer than that of the internal reset circuit.
Figure 5.4 – Power on sequence of GL850G
5.2.2 PGANG/SUSPND Setting
To save pin count, GL850G uses the same pin to decide individual/gang mode as well as to output the
suspend flag. The individual/gang mode is decided within 20us after power on reset. Then, about 50ms later,
this pin is changed to output mode. GL850G outputs the suspend flag once it is globally suspended. For
individual mode, a pull low resister greater than 100K
resister greater than 100K
should be placed. In figure 5.5, we also depict the suspend LED indicator
schematics. It should be noticed that the polarity of LED must be followed, otherwise the suspend current
will be over spec limitation (2.5mA).
©2000-2008 Genesys Logic Inc. - All rights reserved.
GL850G USB 2.0 Low-Power HUB Controller
PCB
PCB
Silicon
Silicon
R
R
RESETJ pin (Low active)
RESETJ pin (Low active)
1
1
EXT
EXT
C
C
R
R
1
1
2
2
OR
OR
INT
INT
Power good reset circuit
Power good reset circuit
(connected to internal 3.3V)
(connected to internal 3.3V)
Figure 5.3 – Power on reset diagram
Power good voltage, 2.5~2.8V
μ
2.7
s
should be placed. For gang mode, a pull high
Reset
Reset
DVDD
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