Rev: 13 September 2005
Class 2 Bluetooth module - F2M03C2
Datasheet
6.2 USB Interface
F2M03 USB devices contain a full-speed (12Mbits/s) USB interface, capable of driving a USB cable
directly. No external USB transceiver is required. The device operates as a USB peripheral, responding to
requests from a master host controller such as a PC. Both the OHCI and the UHCI standards are
supported. The set of USB endpoints implemented behave as specified in the USB section of the Bluetooth
specification v1.1, part H2. As USB is a master-slave orientated system, F2M03 only supports USB slave
operation.
6.2.1 USB Data Connections
The USB data lines emerge as pins USB_DP (USB_D+) and USB_DN (USB_D-) on the package. To match
the connection to the characteristic impedance of the USB cable series resistors are connected internally of
the F2M03C2. No external resistors are needed for either USB_D+ or USB_D- (valid for F2M03C2 only).
6.2.2 USB Pull-up Resistor
F2M03 features an internal USB pull-up resistor. This pulls the USB_DP pin weakly high when F2M03 is
ready to enumerate. It signals to the PC that it is a full-speed (12Mbit/s) USB device.
The USB internal pull-up is implemented as a current source, and is compliant with 7.1.5 of the USB
specification v1.1. The internal pull-up pulls USB DP high to at least 2.8V when loaded with a 15k
-5%
pull-down resistor (in the hub/host) (when VDD=3.1V). This presents a thevenin resistance to the host of at
least 900 ohms. Alternatively, an external 1.5kO pull-up resistor can be placed between a PIO line and DP
on the USB cable. The firmware must be alerted to which mode is used (contact Free2move). The default
setting uses the internal pull-up resistor.
6.2.3 Power Supply
The minimum output high voltage for USB data lines is 2.8V. To safely meet the USB specification, the
voltage on terminals must be an absolute minimum of 3.1V. Free2move recommends 3.3V for optimal USB
signal quality.
6.2.4 Self-Powered Mode
In self-powered mode, the circuit is powered from its own power supply and not from the VBUS (5V) line of
the USB cable. It draws only a small leakage current (below 0.5mA) from VBUS on the USB cable. This is
the easier mode for which to design for, as the design is not limited by the power that can be drawn from
the USB hub or root port. However, it requires that VBUS be connected to F2M03 via a resistor network
(Rvb1 and Rvb2), so F2M03 can detect when VBUS is powered up. F2M03 will not pull USB_D+ high when
VBUS is off.
Connections to F2M03 for Self-Powered Mode
2003 Free2move AB
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