19-3984; Rev 3; 1/10
Wired Remote Controller
General Description
The MAX11041 wired remote controller converts up to
30 different pushbuttons into an I
2
C register. Together
with low-cost pushbutton switches and 1% resistors,
the MAX11041 is a total solution over a single-wire
interface. A wired remote controller easily piggybacks
to a standard 3.5mm headphone jack using a fourth
contact or one of the audio signals.
To conserve battery life, the MAX11041 consumes only
5µA (typ) while reading keypresses in real time without
microprocessor (µP) polling. The device sends the
debounced keypress along with key duration to the
application processor over the I
2
C interface. An 8-word
FIFO buffer records up to four keypress events to allow
plenty of time for the application processor to respond
to the MAX11041.
The MAX11041 includes ±15kV ESD protection devices
on the FORCE and SENSE inputs to ensure IEC 61000-4-2
compliance without any external ESD devices.
The MAX11041 is available in a 12-pin TQFN package.
The device is specified over the extended temperature
range (-40°C to +85°C).
Features
o
Detect Up to 30 Different Keys and Jack
Insertion/Removal
o
Works with Either 32Ω or 16Ω Headphones
o
Adds Remote-Control Functionality to Devices
Using a Simple Resistor and Switch Array
o
Low-Power Operation Consuming a Supply
Current of Only 5µA (typ)
o
Works with Standard 2.5mm or 3.5mm 4-Pin
Headphone Jacks
o
Supports Hold Function to Lockout Keys
o
100kHz/400kHz I
2
C Interface
o
Single 1.6V to 3.6V Supply Voltage Range
o
±15kV ESD Protection (IEC 61000-4-2)
MAX11041
Ordering Information
PART
MAX11041ETC+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
12 TQFN-EP*
Applications
*EP
= Exposed pad.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
Multimedia Controls for
Multimedia-Enabled
Cell Phones
Keyboard Encoder for
Slider, Flip, and other
Cell Phones
Portable Media Players
MP3, CD, DVD Players
PDAs
Digital Still Cameras
PDA Accessory
Keyboards
Multimedia Desktop
Speakers
Portable Game
Consoles
Pin Configuration
SHDN
7
6
A0
5
SDA
SCL
8
TOP VIEW
9
INT
10
V
DD
11
MAX11041
+
1
GND
2
SENSE
3
V
DD
A1
FORCE 12
4
N.C.
THIN QFN
(4mm x 4mm x 0.6mm)
EXPOSED PAD CONNECTED TO GND.
________________________________________________________________
Maxim Integrated Products
1
For pricing delivery, and ordering information please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Wired Remote Controller
MAX11041
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ...........................................................-0.3V to +4.0V
INT
to GND .................................................-0.3V to (V
DD
+ 0.3V)
SCL, SDA, A1, A0,
SHDN
to GND.........................-0.3V to +4.0V
FORCE, SENSE to GND.........................................................±6V
Current into Any Pin..........................................................±50mA
Maximum ESD per IEC 61000-4-2
Human Body Model, FORCE, SENSE............................±15kV
FORCE, SENSE Short to GND....................................Continuous
Junction Temperature ......................................................+150°C
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) .......................................+260°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
DD
= +1.6V to 3.6V, C
SENSE
= 10nF, R
SENSE
= 10kΩ, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
KEY DETECTION CHARACTERISTICS
Detectable Keys
Maximum Switch Resistance
Maximum Switch Bounce Time
External Resistor Tolerance
SWITCH DEBOUNCE
Debounce Analog Time Constant
Chatter Rejection
Rising Voltage Debounce Time
t
CPW
C
SENSE
= 10nF, external resistor from
FORCE to SENSE is 10kΩ (R
SENSE
)
Pulses shorter than this are ignored
Time required for a new voltage (due to
keypress) to be detected and stored in
FIFO
Time required for detection of key release
and final time duration to be stored in FIFO
(Note 2)
(Note 2)
One tick
MSB is overflow bit
0
0.4
18
18
ms
ms
ms
Provided the keys meet the next three
specifications; R
JACK
connected; use
recommended circuit
(Note 1)
(Note 1)
(Note 1)
30
100
13
±1
Keys
Ω
ms
%
Falling Voltage Debounce Time
Jack Insertion Debounce Time
Jack Removal Debounce Time
DURATION COUNTER
Duration-Counter Resolution
Duration-Counter Range
Duration-Counter Accuracy
t
LPWS
18
18
18
32
127
±20
0.7 x
V
DD
0.3 x
V
DD
-10
9
10
+10
ms
ms
ms
ms
Counts
%
DIGITAL INPUTS (SDA, SCL,
SHDN,
A0, A1)
Input High Voltage
Input Low Voltage
Input Leakage Current
Input Hysteresis
Input Capacitance
V
IH
V
IL
I
IH
, I
IL
V
V
µA
%V
DD
pF
2
_______________________________________________________________________________________
Wired Remote Controller
MAX11041
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +1.6V to 3.6V, C
SENSE
= 10nF, R
SENSE
= 10kΩ, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
DIGITAL OUTPUTS (SDA,
INT)
Output High Voltage (INT)
Output Low Voltage (INT)
Output High Leakage Current
Output Low Voltage (SDA)
V
OH
V
OLINT
I
OHL
V
OLSDA
I
SOURCE
≤
2mA
I
SINK
≤
2mA
V
OUT
= V
DD
I
OL
= 3mA for V
DD
> 2V
I
OL
= 3mA for V
DD
< 2V
0.9 x
V
DD
0.1 x
V
DD
1
0.4
0.2 x
V
DD
0
1.3
0.6
1.3
0.6
0.6
0
100
(Note 3)
(Note 3)
V
DD
= 3.6V (Note 3)
V
DD
= 2.4V to 3.6V
SDA Transmitting Fall Time
t
FT
V
DD
= 1.6V to 2.4V
Setup Time for STOP Condition
Bus Capacitance
Pulse Width of Suppressed Spike
t
SU,STO
C
b
t
SP
0
20 +
C
b
/ 10
20 +
C
b
/ 10
20 +
C
b
/ 10
20 +
C
b
/ 20
20 +
C
b
/ 20
0.6
400
50
300
300
250
250
ns
375
µs
pF
ns
900
400
V
V
µA
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
I2C TIMING CHARACTERISTICS (see Figure 1)
Serial Clock Frequency
Bus Free Time Between STOP
and START Conditions
Hold Time (Repeated) START
Condition
SCL Pulse-Width Low
SCL Pulse-Width High
Setup Time for a Repeated
START Condition
Data Hold Time
Data Setup Time
SDA and SCL Receiving Rise
Time
SDA and SCL Receiving Fall
Time
SDA Transmitting Rise Time
f
SCL
t
BUF
t
HD,STA
t
LOW
t
HIGH
t
SU,STA
t
HD,DAT
t
SU,DAT
t
RR
t
FR
t
RT
kHz
µs
µs
µs
µs
µs
ns
ns
ns
ns
ns
____________________________________________________________________________________
3
Wired Remote Controller
MAX11041
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= +1.6V to 3.6V, C
SENSE
= 10nF, R
SENSE
= 10kΩ, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
POWER SUPPLIES
Power-Supply Voltage
Average Operational Supply
Current
Shutdown Power-Supply Current
Jack Current
Key Current
SHDN
High to Part Active
V
DD
I
DDOP
I
DDSHDN
I
DDJACK
Excluding jack/key current
Jack inserted, R
JACK
= 619kΩ
Excluding jack/key current
Flowing when jack is inserted
Wake-up time
4
90
5
1.6
5
8
1
3.6
20
V
µA
µA
µA
µA
ms
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
I
DDBUTTON
Flowing when keys pressed (Note 4)
Note 1:
Note 2:
Note 3:
Note 4:
Recommended properties of external switch for proper detection of 30 keys or key combinations.
See the
Jack Insertion/Removal Detection
section.
C
b
is the bus capacitance in pF.
Key current depends on external key resistors and is calculated by V
DD
/ (30.1kΩ + R
SW
).
START CONDITION
(S)
SDA
REPEAT START CONDITION
(Sr)
t
RR,
t
RT
t
FR,tFT
STOP CONDITION
(P)
t
BUF
t
HD,STA
t
HD,DAT
t
SU,DAT
t
SU,STA
t
HD,STA
t
SU,STO
SCL
START CONDITION
(S)
t
HIGH
t
RR
t
FR
t
LOW
Figure 1. I
2
C Serial-Interface Timing
4
_______________________________________________________________________________________
Wired Remote Controller
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
MAX11041
DEBOUNCE SCOPE SHOT (FALLING)
MAX11041 TOC01
DEBOUNCE SCOPE SHOT (RISING)
MAX11041 TOC02
KEYPRESS RELEASE SCOPE SHOT*
MAX11041 TOC03
V
SENSE
V
SENSE
V
SENSE
INT
DEBOUNCED KEY
ADDED TO FIFO
µP
READS FIFO
INT
DEBOUNCE KEY ADDED
TO FIFO
µP
READS
FIFO
INT
DEBOUNCE KEY ADDED
TO FIFO
µP
READS
FIFO
10ms/div
10ms/div
10ms/div
V
DD
SUPPLY CURRENT vs. VOLTAGE
MAX11041 TOC04
V
DD
SHUTDOWN SUPPLY CURRENT
vs. VOLTAGE
NO JACK INSERTED
MAX11041 TOC05
7.0
NO JACK INSERTED
6.5
T
A
= +85°C
6.0
I
DD
(µA)
1.00
0.75
I
DD
(µA)
5.5
T
A
= +25°C
5.0
0.50
T
A
= +85°C
T
A
= -40°C
0.25
4.5
4.0
1.6
2.1
T
A
= -40°C
0
2.6
V
DD
(V)
3.1
3.6
1.6
2.1
2.6
V
DD
(V)
3.1
3.6
T
A
= +25°C
*Oscilloscope
shots are taken with simulated bounce and chatter. Real switches will exhibit different bounce and chatter characteristics.
____________________________________________________________________________________
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