STULPI01ATBR View Datasheet(PDF) - STMicroelectronics

Part Name

Description

Manufacturer

STULPI01ATBR

High speed USB On-The-Go ULPI transceiver

STMicroelectronics 

STULPI01A - STULPI01B

Block description

6.6

External charge pump

It is possible to use an external charge pump or power switch controlled by the PSWn pin

(active low open drain). This functionality is controlled by DrvVbus and DrvVbusExternal

ULPI OTG Control register bits.

6.7

VBUS comparators and VBUS over current (OC) detector

These comparators monitor the VBUS voltage.

VBUS valid status signalizes that the voltage is above the VBUS_VLD level (4.4 V). Session

valid status signalizes that the VBUS voltage is above the VSESS_VLD level (0.8 to 2.0 V).

Session end detector signalizes VBUS voltage is below VSESS_END level.

STULPI01 also implements embedded VBUS over current detector which compares VBUS

voltage to external analog 5 V reference signal applied to VB_REF_FAULT pin.

6.8

Note:

VB_REF_FAULT pin

VBUS over-current conditions can be monitored by either internal or an external OC detector.

The internal OC detector is enabled when over-current_PD bit in the Power Control register

(Vendor-specific area) is set to 0b and Use External VBUS Indicator is set to 1b. In this

mode, the VB_REF_FAULT pin functions as the input of the analog reference for internal

over-current detector.

If the external charge pump is already equipped with an over-current detector, its output can

be also monitored through VB_REF_FAULT pin, but over-current_PD bit must be set to 1b.

In this mode VB_REF_FAULT will function as standard digital input pin with 5 V tolerance.

Functionality of VB_REF_FAULT pin can be seen in more detail (on Figure 6).

After reset, over-current_PD bit is 1b, internal over-current detector is disabled.

Figure 6. VB_REF_FAULT pin functionality

VBUS

VBREF_FAULT

VBUS

+

REF -

VBUSVLD

VBUS

+

VBREF

-

VBOC

/EN

Internal VBUS Valid

0

1

[0,X]

RX CMD VBUS Valid

[1,0]

[1,1]

RIN_VBREF

FAULT

SCHMIT

(5 V TOLERANT)

2

EN

[UseExternalVbusIndicator, IndicatorPassthru]

OverCurrent_PD or neg (UseExternalVbusIndicator)

IndicatorComplement

19/44

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