User Manual

Rev: c
Low power Bluetooth™ Module with antenna- F2M03GLA
Datasheet
6.2 USB Interface
F2M03 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
v2.0+EDR. As USB is a master-slave orientated system, F2M03 only supports USB slave operation.
Note: The USB interface can only be used with the HCI firmware
6.2.1 USB Data Connections
The USB data lines emerge as pins USB_DP (USB +) and USB_DN (USB -) on the package. These
terminals are connected to the internal USB I/O buffers of F2M03 and therefore have low output
impedance. To match the connection to the characteristic impedance of the USB cable, series resistors
must be connected to both USB + and USB -.
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 15kΩ-5%
pull-down resistor (in the hub/host) (when VDD=3.1V). This presents a the venin resistance to the host of at
least 900Ω. Alternatively, an external 1.5kΩ pull-up resistor can be placed between a PIO line and D+ 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 + high when
VBUS is off.
PIO
USB +
USB –
USB ON
Connections to F2M03 for Self-Powered Mode
The terminal marked USB ON can be any free PIO pin. The PIO pin selected must be registered by settings in firmware (contact
Free2move) to the corresponding pin number
© 2006 Free2move AB
Page 20(44)