CAP1298
8-Channel Capacitive Touch Sensor Controller with
Proximity Detection & Signal Guard
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 / I
2
C 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
2013-2015 Microchip Technology Inc.
DS00001571B-page 1
CAP1298
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced.
If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at
docerrors@microchip.com.
We welcome your feedback.
Most Current Data Sheet
To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:
http://www.microchip.com
You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for cur-
rent devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the
revision of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site;
http://www.microchip.com
• Your local Microchip sales office (see last page)
When contacting a sales office, please specify which device, revision of silicon and data sheet (include -literature number) you are
using.
Customer Notification System
Register on our web site at
www.microchip.com
to receive the most current information on all of our products.
DS00001571B-page 2
2013-2015 Microchip Technology Inc.
CAP1298
Table of Contents
1.0 Introduction ..................................................................................................................................................................................... 4
2.0 Pin Description and Configuration .................................................................................................................................................. 8
3.0 Functional Description .................................................................................................................................................................. 21
4.0 Register Descriptions .................................................................................................................................................................... 58
5.0 Operational Characteristics ........................................................................................................................................................... 69
6.0 Package Outline ............................................................................................................................................................................ 85
Appendix A: Data Sheet Revision History ........................................................................................................................................... 91
The Microchip Web Site ...................................................................................................................................................................... 93
Customer Change Notification Service ............................................................................................................................................... 93
Customer Support ............................................................................................................................................................................... 93
Product Identification System ............................................................................................................................................................. 94
2013-2015 Microchip Technology Inc.
DS00001571B-page 3
CAP1298
1.0
1.1
INTRODUCTION
Block Diagram
FIGURE 1-1:
CAP1298 BLOCK DIAGRAM
VDD
GND
SMCLK
CS5 /
SG
Capacitive Touch Sensing Algorithm
SMBus
Protocol
SMDATA
ALERT#
CS1
CS2
CS3
CS4
CS6
CS7
CS8
1.2
Pin Diagrams
FIGURE 1-2:
CAP1298 14-PIN SOIC
CS2
CS1
SMDAT
SMCLK
1
2
CAP1298
4
5
14
13
12
11
10
9
8
CS3
CS4
CS5/SG
CS6
CS7
CS8
GND
ALERT# 3
N/C 6
VDD 7
DS00001571B-page 4
2013-2015 Microchip Technology Inc.
CAP1298
FIGURE 1-3:
CAP1298 PIN DIAGRAM (16-PIN QFN)
CS1
CS2
CS3
14
CS4
13
12
11
Exposed pad
SMCLK
VDD
3
4
5
6
7
8
10
9
CS7
CS8
16
15
ALERT#
SMDATA
1
2
CS5 / SG
CS6
GND
N/C
N/C
1.3
Pin Description
TABLE 1-1:
QFN Pin
#
1
PIN DESCRIPTION FOR CAP1298
SOIC Pin #
Pin Name
Pin Function
ALERT# - Active low alert / interrupt out-
put for SMBus alert
SMDATA - Bi-directional, open-drain
SMBus or I
2
C data - requires pull-up
resistor
SMCLK - SMBus or I
2
C clock input -
requires pull-up resistor
Positive Power supply
Not internally connected
Not internally connected
Ground
Ground
Capacitive Touch Sensor Input 8
Capacitive Touch Sensor Input 7
Pin Type
Unused
Connection
Connect to
Ground
n/a
3
ALERT#
GND
OD
2
4
SMDATA
DIOD
3
4
5
6
7
8
9
10
5
7
6
-
8
-
9
10
SMCLK
VDD
N/C
N/C
GND
GND
CS8
CS7
DI
Power
n/a
n/a
Power
Power
AIO
AIO
n/a
n/a
Connect to
Ground
Connect to
Ground
n/a
n/a
Connect to
Ground
Connect to
Ground
2013-2015 Microchip Technology Inc.
DS00001571B-page 5
单片机
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
