AN92584 Datasheet, PDF (6/42 Pages) Ramtron International Corporation – Designing for Low Power and Estimating Battery Life for BLE Applications

Designing for Low Power and Estimating Battery Life for BLE Applications
2.5
2.5.1
Low-Power Implementation
This section discusses how to implement the low-power-mode recommendations in your BLE project. It involves two
steps:
1. Configure your project in PSoC Creator™.
2. Implement the recommendations in your application code.
PSoC Creator Configuration
The following configurations should be implemented in your project to ensure a low-power operation.
Low-Frequency Clock (LFCLK) Selection
The LFCLK in the system must be set to use the WCO to operate the BLESS in the DEEPSLEEP mode.
1. Access this setting in the Clocks tab of the .cydwr file in your project.
2. Click Edit Clock to open the Configure System Clocks window, as shown in Figure 3.
3. Go to the Low Frequency Clocks tab.
4. Confirm that the WCO tab is selected and the WCO is selected as LFCLK.
5. Close the window.
Figure 3. LFCLK Setting
WCO Power Mode
The WCO supports two modes of operation: low power and high power. The high-power mode is required for a fast
start up of the oscillator block upon power up of the chip. After the oscillation has stabilized, the WCO must be set to
operate in the low-power mode to reduce current consumption.
1. Access this setting under the Clocks tab of the .cydwr file.
2. Click Edit Clock to open the Configure System Clocks window, as shown in Figure 4.
3. Go to the Low Frequency Clocks tab.
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Document No. 001-92584 Rev. *A
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