AN91267 Datasheet, PDF (48/62 Pages) Ramtron International Corporation – Getting Started with PSoC

Getting Started with PSoC® 4 BLE
SAR ADC with Hardware Sequencer
PSoC 4 BLE has a 12-bit, 1-Msps Successive Approximation Register (SAR) ADC with input channels that support
programmable resolution and single-ended or differential input options. The number of GPIOs limits the number of ADC input
channels that can be implemented.
The SAR ADC has a hardware sequencer that can perform an automatic scan on as many as eight channels without CPU
intervention. It also supports preprocessing operations such as accumulation and averaging of the output data on these eight
channels.
You can trigger a scan with a variety of methods, such as firmware, timer, pin, or UDB, giving you additional design flexibility.
For more information, refer to the PSoC 4 SAR ADC Component datasheet.
Low-Power Comparators
PSoC 4 BLE devices have low-power comparators capable of operating in all system power modes except the Stop mode. In
a power-sensitive design, when the device goes into low-power modes, you can use the low-power comparator to monitor
analog inputs and generate an interrupt that can wake up the system.
For more information, refer to the PSoC 4 Low-Power Comparator Component datasheet.
Capacitive Touch Sensing (CapSense)
Capacitive touch sensors use human-body capacitance to detect the presence of a finger on or near a sensor. Capacitive
sensors are aesthetically superior, easy to use, and have long lifetimes.
The CapSense feature in PSoC 4 BLE offers unprecedented signal-to-noise ratio; best-in-class liquid tolerance; and a wide
variety of sensor types such as buttons, sliders, track pads, and proximity sensors.
A Cypress-supplied software Component makes capacitive sensing design very easy; the Component supports an automatic
hardware-tuning feature called SmartSense™ and provides a gesture-recognition library for trackpads and proximity sensors.
Two current DACs (IDACs), one 7-bit and one 8-bit, in the CapSense block are available for general-purpose use if capacitive
sensing is not used. The comparator in the CapSense block is also available for general-purpose use.
For more information, see the PSoC 4 CapSense Design Guide.
Segment LCD Direct Driver
Most low-power, portable, handheld devices such as glucose meters, multimeters, and blood pressure monitors use a
segment LCD to display information. Segment LCDs typically require an external driver to interface with a microcontroller.
PSoC 4 BLE includes an integrated low-power LCD driver that can directly drive segment LCD glass.
PSoC 4 BLE can drive LCDs with as many as 4 common and 32 segment electrodes. The segment LCD driver can retain a
static display in Deep-Sleep mode with a system current consumption as low as 7 µA.
For more information, see AN87391  PSoC 4 Segment LCD Direct Drive.
Applications
The use of programmable analog peripherals in different BLE applications is listed in Table 5.
Table 5. Applications of Programmable Analog Peripherals
Applications
Analog Peripherals
Health and Fitness
Opamp: TIA (heart-rate measurement)
Opamp: Follower (analog- reference buffer)
ADC (sampling heart-rate signal)
CapSense (user interface on a wrist band)
Segment LCD (display on a wrist band)
Sensor Hub
ADC (analog sensor interface)
Analog Mux (multiple-sensor input)
Opamps (signal amplifier)
Segment LCD (UI)
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