User's Manual

DW-SBTM1_UM_00.doc

Stand-alone Bluetooth Module User Manual

Page 7

Note: VDD2 is internally regulated from VDD1 coming through VDD_ANA pin. It can be

supplied externally, but then tight regulation and filtering is required (less than 10mVpp).

Check original manufacturer IC data book for more details (Check BOM for part number)

RESET pin is active high and has to stay on for at least 5ms for a proper reset of the

module.

Pin name Pin state during reset

UART_TX Output tri-stated with weak pull-up

UART_RX Input with weak pull-down

UART_RTS Output tri-stated with weak pull-up

UART_CTS Input with weak pull-down

SPI_CSB Input with weak pull-up

SPI_CLK Input with weak pull-down

SPI_MISO Output tri-stated with weak pull-down

SPI_MOSI Input with weak pull-down

Usage requirements and recommendations:

(a) Pre-regulate VDD1 to 3.3V. Allowable input range is 2.2V to 3.6V. The chip

already has internal regulator for all RF circuitry, and CPU circuitry.

(b) Use chokes on the supply line to limit the amount of conducted and radiated

signals. External power supply filtering is required to achieve good radio

performance.

conducted interference

(d) Placing of the module should be done such manner that the closest PCB is at

least 3mm away from the antenna and preferably on the bottom side. The

antenna should have no metallic obstruction on at leas two sides parallel to

the long dimension of antenna (Antenna should not be shielded!!!)

(e) Care should be taken in placing the module such the antenna does not radiate

directly into sensitive circuitry, and thus affecting the functionality of the

whole device.

NOT APPLICABLE (future development only):

(f) If using the USB port, and powering from VBUS, this has to pass through a LC

filter (10uH and 2.2uF), able to withstand currents of 100mA to 120mA. Do

not use tantalum capacitors – they do not handle well rapid voltage changes

during hot plugging.

(g) If using USB port, D+ and D- should be of equal length