User's Manual

BT900-Sx Hardware Integration Guide
Intelligent BTv4.0 Dual Mode Module
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22 CONN-HIG-BT900
4.3 Peripheral block current consumption
The values below are calculated for a typical operating voltage of 3 V.
Table 10: UART Power Consumption
Parameter Min Typ Max Unit
UART Run current @ 115200 bps xxx uA
UART Run current @ 1200 bps xxx uA
UART Baud rate 1.2 115.2 kbps
Table 11: SPI Power Consumption
Parameter Min Typ Max Unit
SPI Master Run current @ 125 kbps xxx uA
SPI Master Run current @ 4 Mbps xxx uA
SPI bit rate 0.125 8 Mbps
Table 12: I2C Power Consumption
Parameter Min Typ Max Unit
I2C Run current @ 100 kbps xxx uA
I2C Run current @ 400 bps xxx uA
I2C Bit rate 100 400 kbps
Table 13: ADC
Parameter Min Typ Max Unit
ADC current during conversion xxx uA
The above current consumption is for the particular peripheral only and to operate that
peripheral requires some other internal blocks which consume fixed amount of base current
(~xxxuA).
This base current of ~xxxx uA is consumed when the UART, SPI, I2C, or ADC is opened (operated).
For asynchronous interface like the UART (asynchronous as the other end can communicate at
any time), the UART (on BT900) must kept open (by a command in smart BASIC application script)
resulting in the base current consumption penalty.
For synchronous interface like the I2C or SPI (since BT900 side is the master), the interface can be
closed and opened only (by a command in smart BASIC application script) when needed,
resulting in current saving (no base current consumption penalty). Similar argument for ADC
(open ADC when needed).