BISM2 Datasheet, PDF (11/31 Pages) Laird Tech Smart Technology – The BISM2 Bluetooth Serial Module is one of the most compact complete

BISM2 Bluetooth™
Hardware Integration Guide
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 module’s hardware specification allows for a voltage range of 3.6 to 7.0 at Vcc. Tests have shown that
there is no significant difference in current draw when Vcc is 5 or 6 V. Therefore the data presented below
pertains to Vcc levels of 3.6 and 5 V only. Tests have shown that where power drain is an issue, it is best to
keep Vcc at the lower end of the range.
The UART baudrate has a bearing on power drain 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.
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 transferring data and when data is
transfers at the maximum rate possible. The AT command set document describes how to configure the
module for optimal power performance.
Baud
Idle Mode, S512 = 1
Wait for connection or Discoverable Mode, AT+BTP
S508 = S510= 640, S409= S511 = 11*
Wait for Connection or Discoverable Mode, AT+BTP
S508=S510=1000, S509 = S511 = 11*
Inquiring Mode, AT+BTI
Connecting Mode (ATDxxx)
Connected Mode (No Data Transfer)
Connected Mode (Max Data Transfer)
* Calculated figures
3.6 V
5.0 V
3.6 V
5.0 V
3.6 V
5.0 V
3.6 V
5.0 V
3.6 V
5.0 V
3.6 V
5.0 V
3.6 V
5.0 V
9,600
1.60
2.00
59.00
65.00
2.75
3.26
50.00
54.00
50.00
54.00
6.00
7.20
21.50
24.50
38,400
1.80
2.10
59.00
65.00
2.94
3.36
50.00
54.00
50.00
54.00
6.10
7.20
22.50
26.00
115,200
1.96
2.30
59.00
65.00
3.10
3.55
50.00
54.00
50.00
54.00
6.40
7.40
24.50
28.00
460,800
3.00
3.40
59.00
65.00
4.12
4.63
50.00
54.00
50.00
54.00
7.20
8.20
32.50
36.00
Note: These figures were obtained with pre-production firmware. Production values are typically 20%
lower.
Embedded Wireless Solutions Support
Center: http://ews-
support.lairdtech.com
www.lairdtech.com/bluetooth
11
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