Rainbow Electronics DAB-WLS-C21 (BlueTooth) - Manual (Page 8)

www.EZURiO.com
DSH_BTM402_0v9 BISM2 PA Data Sheet.DOC © 2007 EZURiO Ltd 8
RESET 13 I V
IL
max=1.0V
V
IH
min=2.3V
Active HIGH. The Reset input
contains a 10kΩ pull down
resistor to ground.
Terminology:
USB Signal Levels. vdd_usb refers to the internal voltage generated by the LDO regulator on the
module, which is typically 3.3V. Hence 0.3vdd_usb and 0.7vdd_usb correspond to 1.0V to 2.3V. If
Vcc falls below the recommended minimum of 3.6V, these values will be reduced.
4. I/O Characteristics
4.1 Power Consumption
The current drain from the Vcc power input line is dependent on various factors. The three most
significant factors are the voltage level at Vcc, UART Baudrate and the operating mode.
The hardware specification for the Module allows for a voltage range of 3.6 to 5.0 at Vcc. The unit
includes a linear regulator and tests have shown that there is no significant difference in current draw
when Vcc changes within the operating limits. Tests have shown that where power dissipation is an
issue, it is best to keep Vcc at the lower end of the range.
The UART baudrate has a bearing on power dissipation because as is normal for digital electronics,
the power requirements increase linearly with increasing clocking frequencies. Hence higher
baudrates result in a higher current drain.
Finally with regards to operating mode the significant modes are; idle, waiting for a connection,
inquiring, initiating a connection, sniff and connected. With connected mode, it is also relevant to
differentiate between no data being transferred and when data is being transferred at the maximum
rate possible. The AT command Set document describes how to configure the Module for optimal
power performance.
4.1.1 Typical Current Consumption in mA
Vcc = 4.1V, Baudrate = 115,200 bps,
Range = 10 metres
Current
(mA)
Idle Mode, S512=1 1.5
Wait for Connection Or Discoverable Mode,
AT+BTP
S508=S510=640, S509=S511=320
57
Wait for Connection Or Discoverable Mode,
AT+BTP
S508=S510=1000, S509=S511=11
3.4
Inquiry Mode, AT+BTI 114
Connecting Mode (ATDxxx) 129
Connected Mode (No Data Transfer) 10
Connected Mode (Max Data Transfer) 46
See section 8 for details of different low power modes.