FUNCTIONAL DEVICE OPERATION
CONNECTIVITY
CONNECTIVITY
USB INTERFACE
The MC13892 contains the regulators required to supply the PHY contained in the i.MX51, i.MX37, i.MX35, and i.MX27
processors. The regulators used to power the external PHY in the i.MX51 and i.MX37 are VUSB, VUSB2, and VUSB for the
i.MX35 and i.MX27 processors. The MC13892 also provides the 5.0 V supply for USB OTG operation. The USB interface may
be used for portable product battery charging (refer to Battery Interface and Control for more details on the charging system).
Finally included are comparators/detectors for VBUS and ID detection. The USB interface is illustrated in the following diagram.
Figure 32. USB Interface
SUPPLIES
The VUSB regulator is used to supply 3.3 V to the external USB PHY. The UVBUS line of the USB interface is supplied by the
host in the case of host mode operation, or by the integrated VBUS generation circuit, in the case of USB OTG mode operation.
The VBUS circuit is powered from the SWBST boost supply to ensure OTG current sourcing compliance through the normal
discharge range of the main battery.
The VUSB regulator can be supplied from the UVBUS wire of the cable when supplied by a host in the case of host mode
operation, or by the SWBST voltage brought in at the VINUSB pin and internally connected to the VBUS pin for OTG mode
operation. The VUSBIN SPI bit is used to make the selection between host or OTG mode operation as defined in Table 99.
13892
Analog Integrated Circuit Device Data
110
Freescale Semiconductor
FREESCALE [ Freescale ]
