CY8C20180
Document Number: 001-17346 Rev. *F
Page 6 of 16
Modes of Operation
CapSense Express devices are configured to operate in any of
the following three modes to meet different power consumption
requirements:
■ Active Mode
■ Sleep Mode
■ Deep Sleep Mode
Active Mode
In the active mode, all the device blocks including the CapSense
sub system are powered. Typical active current consumption of
the device across the operating voltage range is 1.5 mA.
Sleep Mode
Sleep mode provides an intermediate power operation mode. It
is enabled by configuring the corresponding device register.
When enabled, the device enters sleep mode and wakes up after
a specified sleep interval. It scans the capacitive sensors before
going back to sleep again. The device can also wake up from
sleep mode with a GPIO interrupt. The following sleep intervals
are supported in CapSense Express. The sleep interval is
configured through registers.
■ 1.95 ms (512 Hz)
■ 15.6 ms (64 Hz)
■ 125 ms (8 Hz)
■ 1s (1 Hz)
Deep Sleep Mode
Deep sleep mode provides the lowest power consumption
because there is no operation running. In this mode, the device
is woken up only using an external GPIO interrupt. A sleep timer
interrupt cannot wake up a device from deep sleep mode. This
can be treated as a continuous sleep mode without periodic
wakeups. Refer to the application note “CapSense Express
Power and Sleep Considerations - AN44209” for details on
different sleep modes.
Bi-Directional Sleep Control Pin
The CY8C20180 requires a dedicated sleep control pin to allow
reliable I2C communication in case any sleep mode is enabled.
This is achieved by pulling the sleep control pin LOW to wake up
the device and start I2C communication. The sleep control pin
can be configured on any of the GPIO. If sleep control feature is
enabled, the device has one less GPIO available for CapSense
and GPIO functions. The sleep control pin can also be
configured as interrupt output pin from CY8C20180 to the host
to acknowledge finger press on any button. To enable bi-direc-
tional feature, user must use I2C-USB bridge program.
[+] Feedback
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
