SX9500
WIRELESS & SENSING
G
ENERAL
D
ESCRIPTION
The SX9500 is a low-cost, very low power 4-channel
capacitive controller that can operate either as a proximity
or button sensor. The SX9500 includes sophisticated on-
chip auto-calibration circuitry to regularly perform sensitivity
adjustments, maintaining peak performance over a wide
variation of temperature, humidity and noise environments,
providing simplified product development and enhanced
performance.
A dedicated transmit enable (TXEN) pin is available to
synchronize capacitive measurements for applications that
require synchronous detection, enabling very low supply
current and high noise immunity by only measuring
proximity when requested.
The SX9500 operates directly from an input supply voltage
of 2.7 to 5.5V, and includes a separate I2C serial bus
supply input to enable communication with 1.8 – 5.5V
hosts. The I2C serial communication bus reports proximity
or touch detection and is used to facilitate parameter
settings adjustment. Upon a proximity detection, the NIRQ
output asserts, enabling the user to either determine the
relative proximity distance, or simply obtain an indication of
detection. The serial bus can also serve to overwrite
detection thresholds and operational settings in the event
the user wants to change them from their factory presets.
Ultra Low Power, Capacitive
Four (4) - Channel Proximity/Button
Controller
DATASHEET
K
EY
P
RODUCT
F
EATURES
2.7 – 5.5V Input Supply Voltage
Capacitive Sensor Inputs
4 fF Capacitance Resolution
Stable Proximity & Touch Sensing With Temperature
Capacitance Offset Compensation to 30pF
Active Sensor Guarding
Automatic Calibration
Ultra Low Power Consumption:
Active Mode:
Doze Mode:
Sleep Mode:
170 uA
18 uA
2.5 uA
400KHz I2C Serial Interface
Four programmable I2C Sub-Addresses
Input Levels Compatible with 1.8V Host Processors
Open Drain NIRQ Interrupt pin
Three (3) Reset Sources: POR, NRST pin, Soft
Reset
-40°C to +85°C Operation
Compact Size: 3 x 3mm Thin QFN package
Pb & Halogen Free, RoHS/WEEE compliant
A
PPLICATIONS
•
•
•
Notebooks
Tablets
Mobile Appliances
O
RDERING
I
NFORMATION
Semtech P/N
SX9500IULTRT
Note1
Package
QFN-20
Eval. Kit
Marki
ng
ZND8
SX9500EVK
Note 1: Quantities are ordered in 3K units per Reel
T
YPICAL
A
PPLICATION CIRCUIT
Figure 1: Typical Application Circuit
Revision 1.6
June 27, 2012
© 2012 Semtech Corporation
1
www.semtech.com
SX9500
WIRELESS & SENSING
Ultra Low Power, Capacitive
Four (4) - Channel Proximity/Button
Controller
DATASHEET
Table of Contents
G
ENERAL
D
ESCRIPTION
........................................................................................................................ 1
K
EY
P
RODUCT
F
EATURES
..................................................................................................................... 1
A
PPLICATIONS
....................................................................................................................................... 1
O
RDERING
I
NFORMATION
...................................................................................................................... 1
T
YPICAL
A
PPLICATION CIRCUIT
............................................................................................................ 1
1
1.1
1.2
1.3
1.4
G
ENERAL
D
ESCRIPTION
............................................................................................................... 5
Pin Diagram
Marking information
Pin Identification
Acronyms
5
5
6
6
7
7
7
8
11
11
11
11
11
12
13
13
13
14
14
15
15
15
16
16
16
16
16
16
17
17
18
18
18
18
19
20
20
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2
E
LECTRICAL
C
HARACTERISTICS
................................................................................................. 7
2.1
Absolute Maximum Ratings
2.2
Recommended Operating Conditions
2.3
Thermal Characteristics
Electrical Specifications
3
3.1
F
UNCTIONAL DESCRIPTION
........................................................................................................ 11
Introduction
3.1.1
General
3.1.2
Parameters and Configuration
3.1.3
Sensor Touch/Proximity Adjustment
3.2
Scan Period
3.3
Operational Modes
3.4
Configuration
3.5
Reset
3.5.1
Power-up
3.5.2
NRST
3.5.3
Software Reset
3.6
Interrupt
3.6.1
Power-up
3.6.2
NIRQ Clearing
4
4.1
4.2
4.3
4.4
4.5
P
IN DESCRIPTIONS
..................................................................................................................... 16
Introduction
V
DD
and SV
DD
TXEN
Capacitor Sensing Interface (CS0, CS1, CS2, CS3, CSG)
Host Interface
4.5.1
NIRQ
4.5.2
SCL, NRST and TXEN
4.5.3
SDA
Introduction
Capacitive Sensor (CS0, CS1, CS2, CS3) Parameters
5.2.1
Set CPS_Digital_GAIN [6:5] (Cap Sensor Gain)
5.2.2
Set CPS_C
IN
R [1:0] (Input Capacitance Range and Resolution)
5.2.3
Set CPS_TRS [4:0] (Detection threshold)
5.2.4
Set CPS_HYST [5:4] (Detection Hysteresis)
5.2.5
Set CPS_AVGDEB[7:6] (Average Pos/Neg Debouncing)
June 27, 2012
© 2012 Semtech Corporation
2
5
5.1
5.2
D
ETAILED
C
ONFIGURATION DESCRIPTIONS
.............................................................................. 18
Revision 1.6
SX9500
WIRELESS & SENSING
Ultra Low Power, Capacitive
Four (4) - Channel Proximity/Button
Controller
DATASHEET
20
21
21
21
22
22
22
22
23
24
25
28
29
30
5.2.6
Set CPS_AVGNEGFILT[5:3] & CPS_AVGPOSFILT[2:0] (Average Neg/Pos Filters)
5.2.7
Set CPS_FS[4:3] (Sampling Frequency)
5.2.8
Set CPS_RES[2:0] (Resolution Factor)
5.2.9
Set CPS_AVGTRS[7:0] (Averaging Threshold)
5.3
Additional Parameter Settings
5.3.1
Set CPS_PERIOD[6:4] (Scan Period)
5.3.2
Set CPS_EN [3:0] (Enable Capacitive Sensor Inputs)
5.3.3
Set IRQ_Enable [6:3] (Enable Interrupt Sources)
6
6.1
6.2
6.3
6.4
I2C I
NTERFACE
........................................................................................................................... 23
I2C Write
I2C Read
Register Overview
Sensor Design
Package Outline Drawing
Land Pattern
7
7.1
7.2
P
ACKAGING
I
NFORMATION
........................................................................................................ 29
LIST OF FIGURES
Figure 1: Typical Application Circuit
.....................................................................................................................1
Figure 2: Pin Diagram
.............................................................................................................................................5
Figure 3: QFN Marking Information
.......................................................................................................................5
Figure 4: I2C Start and Stop timing
.....................................................................................................................10
Figure 5: I2C Data timing
......................................................................................................................................10
Figure 6 Scan Period.............................................................................................................................................
11
Figure 7: Power-up vs. NIRQ
................................................................................................................................13
Figure 8: Hardware Reset
.....................................................................................................................................14
Figure 9: Software Reset
......................................................................................................................................14
Figure 10: NIRQ Output Simplified Diagram
......................................................................................................16
Figure 11: SCL/TXEN/NRST
.................................................................................................................................17
Figure 12: SDA Simplified Diagram
.....................................................................................................................17
Figure 13: I2C Write...............................................................................................................................................
23
Figure 14: I2C Read
...............................................................................................................................................24
Figure 15: Typical Touch/Proximity Capacitive Sensor
....................................................................................28
Figure 16: Package Outline Drawing
...................................................................................................................29
Figure 17: Package Land Pattern
........................................................................................................................30
Revision 1.6
June 27, 2012
© 2012 Semtech Corporation
3
www.semtech.com
SX9500
WIRELESS & SENSING
Ultra Low Power, Capacitive
Four (4) - Channel Proximity/Button
Controller
DATASHEET
LIST OF TABLES
Table 1: Pin Description
.........................................................................................................................................6
Table 2: Absolute Maximum Ratings
....................................................................................................................7
Table 3: Recommended Operating Conditions
....................................................................................................7
Table 4: Thermal Characteristics
...........................................................................................................................7
Table 5: Electrical Characteristics
.........................................................................................................................9
Table 6: I2C Timing Specification
........................................................................................................................10
Table 7: I2C Sub-Address Selection....................................................................................................................
12
Table 8: CPS_Digital_GAIN
..................................................................................................................................18
Table 9: C
INPUT
Range and Resolution Register
.................................................................................................18
Table 10: Cap Sensor Threshold
.........................................................................................................................19
Table 11: CPS_HYST
.............................................................................................................................................20
Table 12: CPS_AVGDEB
.......................................................................................................................................20
Table 13: Sampling Frequency Control
..............................................................................................................21
Table 14: CPS Resolution Factor
.........................................................................................................................21
Table 15: Scan Period, Register 0x06
.................................................................................................................22
Table 16: Register Overview
................................................................................................................................28
Revision 1.6
June 27, 2012
© 2012 Semtech Corporation
4
www.semtech.com
SX9500
WIRELESS & SENSING
1 G
ENERAL
D
ESCRIPTION
1.1
Pin Diagram
Ultra Low Power, Capacitive
Four (4) - Channel Proximity/Button
Controller
DATASHEET
Figure 2: Pin Diagram
1.2
Marking information
ZND8
yyww
xxxx
yyww= Date Code
xxxx = Lot Number
Figure 3: QFN Marking Information
Revision 1.6
June 27, 2012
© 2012 Semtech Corporation
5
www.semtech.com