GL850G View Datasheet(PDF) - Genesys Logic

Part Name

Description

Manufacturer

GL850G

USB 2.0 HUB Controller

Genesys Logic 

GL850G USB 2.0 Low-Power HUB Controller

GL850G internally contains a power on reset circuit. The power on sequence is depicted in the next picture.

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.

Power good voltage, 2.5~2.8V

DVDD

Internal reset

≒ 2.7 μs

External reset

Figure 5.3 – 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 100KΩ should be placed. For gang mode, a pull high

resister greater than 100KΩ 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).

RESET#

GANG_CTL

50 ms

Input mode, strapping

to decide individual or

gang mode

Output mode, Indicating

GL850G Is In normal

mode or suspend mode

Figure 5.4 – Timing of PGANG/SUSPEND strapping

©2000-2007 Genesys Logic Inc. - All rights reserved.

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