2013-2015 Microchip Technology Inc. DS00001571B-page 1
General Description
The CAP1298 is a multiple channel capacitive touch
sensor controller. It contains eight (8) individual capac-
itive touch sensor inputs with programmable sensitivity
for use in touch sensor applications. Each sensor input
is calibrated to compensate for system parasitic capac-
itance and automatically recalibrated to compensate
for gradual environmental changes.
In addition, the CAP1298 can be configured to detect
proximity on one or more channels with an optional sig-
nal guard to reduce noise sensitivity and to isolate the
proximity antenna from nearby conductive surfaces
that would otherwise attenuate the e-field.
The CAP1298 includes Multiple Pattern Touch recogni-
tion that allows the user to select a specific set of but-
tons to be touched simultaneously. If this pattern is
detected, a status bit is set and an interrupt is gener-
ated.
The CAP1298 has Active and Standby states, each
with its own sensor input configuration controls. The
Combo state allows a combination of sensor input con-
trols to be used which enables one or more sensor
inputs to operate as buttons while another sensor input
is operating as a proximity detector. Power consump-
tion in the Standby and Combo states is dependent on
the number of sensor inputs enabled as well as averag-
ing, sampling time, and cycle time. Deep Sleep is the
lowest power state available, drawing 5µA (typical) of
current. In this state, no sensor inputs are active, and
communications will wake the device.
Applications
• Desktop and Notebook PCs
• LCD Monitors
• Consumer Electronics
• Appliances
Features
• Eight (8) Capacitive Touch Sensor Inputs
- Programmable sensitivity
- Automatic recalibration
- Calibrates for parasitic capacitance
- Individual thresholds for each button
• Proximity Detection
• Signal Guard
- Isolates the proximity antenna from attenua-
tion
- Reduces system noise sensitivity effects on
inputs
• Multiple Button Pattern Detection
• Power Button Support
• Press and Hold Feature for Volume-like Applica-
tions
• 3.3V or 5V Supply
• Analog Filtering for System Noise Sources
• RF Detection and Avoidance Filters
• Digital EMI Blocker
• 8kV ESD Rating on All Pins (HBM)
• Low Power Operation
- 5µA quiescent current in Deep Sleep
- 50µA quiescent current in Standby (1 sensor
input monitored)
- Samples one or more channels in Standby
• SMBus / I2C Compliant Communication Interface
• Available in a 16-pin 3mm x 3mm QFN RoHS
compliant package
• Available in a 14-pin SOIC RoHS compliant pack-
age
CAP1298
8-Channel Capacitive Touch Sensor Controller with
Proximity Detection & Signal Guard
