Low-Power Design Considerations
AN66308 - CY8CMBR2044 CapSense® Design Guide, Doc. No. 001-66308 Rev. *F
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Sleep Modes
Cypress’s CY8CMBR2044 can be configured to operate in either low-power sleep mode or deep sleep mode.
Low-Power Sleep Mode
When the CY8CMBR2044 device operates in low power sleep mode, the device draws 1 µA when not scanning the
CS inputs. The scan rate determines the amount of time. The behavior of CY8CMBR2044 controller in low-power
sleep mode is described in
Figure 5-1. Low-Power Sleep Mode
Scan all buttons with 20 ms Scan
Rate (Scan time + Sleep time)
NO button touched for
2 secs?
Yes
Scan all buttons with user defined
scan rate.
Is any button active?
Yes
No
No
Because low-power sleep mode does not require a host processor to operate, it is also referred to as standalone
mode.
Deep Sleep Mode
If the CY8CMBR2044 is used in a system with a host processor, the ScanRate/Sleep control pin can be used to
operate in deep sleep mode. When the host processor provides logic high to this input pin, the CY8CMBR2044 is put
into deep sleep mode. This mode consumes 0.1 µA (typ) of current. When the host drives a GND signal to the same
input pin, the CY8CMBR2044 wakes up from sleep and operates in low-power sleep mode.
