Rainbow Electronics MAX11042 User Manual

General Description

The MAX11041/MAX11042 wired remote controllers
convert up to six or 30 different pushbuttons into an
I2C* register. Together with low-cost pushbutton switch­es and 1% resistors, the MAX11041/MAX11042 are
total solutions 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/MAX11042
consume only 5µA (typ) while reading keypresses in
real time without microprocessor (µP) polling. The
devices send the debounced keypress along with key
duration to the application processor over the I2C 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/MAX11042.

The MAX11041/MAX11042 include ±15kV ESD protec­tion devices on the FORCE and SENSE inputs to ensure
IEC 61000-4-2 compliance without any external
ESD devices.

The MAX11041/MAX11042 are available in 12-bump
UCSP™ and 12-pin TQFN packages. The devices are
specified over the extended temperature range
(-40°C to +85°C).

Applications

Features

♦ Detect Up to Six (MAX11042) or 30 (MAX11041)

Different Keys and Jack Insertion/Removal

♦ Work with Either 32Ω or 16Ω Headphones

♦ Add Remote-Control Functionality to Devices

Using a Simple Resistor and Switch Array

♦ Low-Power Operation Consuming a Supply

Current of Only 5µA (typ)

♦ Work with Standard 2.5mm or 3.5mm 4-Pin

Headphone Jacks

♦ Support Hold Function to Lockout Keys

♦ 100kHz/400kHz I2C Interface

♦ Single 1.6V to 3.6V Supply Voltage Range

♦ ±15kV ESD Protection (IEC 61000-4-2)

MAX11041/MAX11042

Wired Remote Controllers

________________________________________________________________ Maxim Integrated Products 1

19-3984; Rev 0; 1/06

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

12

11

10

4

5

SENSE

V

DD

6

GND

SCL

SHDN

SDA

12

V

DD

3

987

FORCE

A0

A1

N.C.

MAX11041
MAX11042

INT

THIN QFN

(4mm x 4mm x 0.6mm)

TOP VIEW

EXPOSED PAD CONNECTED TO GND.

Pin Configurations

Ordering Information

UCSP is a trademark of Maxim Integrated Products, Inc.

*Purchase of I

2

C components from Maxim Integrated Products,
Inc., or one of its sublicensed Associated Companies, conveys
a license under the Philips I

2

C Patent Rights to use these com-

ponents in an I

2

C system, provided that the system conforms

to the I

2

C Standard Specification as defined by Philips.

*EP = Exposed pad.
**Future product—contact factory for availability.

Pin Configurations continued at end of data sheet.

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

PART

MAX11041ETC -40°C to +85°C 12 TQFN-EP* T1244-4

M AX 11041E BC - T** -40°C to +85°C

MAX11042ETC** -40°C to +85°C 12 TQFN-EP* T1244-4

M AX 11042E BC - T** -40°C to +85°C

TEMP

RANGE

PIN­PACKAGE

12 UCSP
(4 x 4 Array)

12 UCSP
(4 x 4 Array)

PKG

CODE

B16-5

B16-5

MAX11041/MAX11042

Wired Remote Controllers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

VDDto 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

ELECTRICAL CHARACTERISTICS

(VDD= +1.6V to 3.6V, C

SENSE

= 10nF, R

SENSE

= 10kΩ, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

KEY DETECTION CHARACTERISTICS

Detectable Keys

Maximum Switch Resistance (Note 1) 100 Ω

Maximum Switch Bounce Time (Note 1) 13 ms

External Resistor Tolerance (Note 1) ±1 %

SWITCH DEBOUNCE

Debounce Analog Time Constant

Chatter Rejection Pulses shorter than this are ignored 18 ms

Rising Voltage Debounce Time t

CPW

Provided the keys meet
the next three
specifications; R
connected; use
recommended circuit

C

= 10nF, external resistor from

SENSE

FORCE to SENSE is 10kΩ (R

Time required for a new voltage (due to
keypress) to be detected and stored in
FIFO

MAX11041 30

JACK

MAX11042 6

SENSE

)

0.4 ms

18 ms

Keys

Falling Voltage Debounce Time t

Jack Insertion Debounce Time (Note 2) 18 ms

Jack Removal Debounce Time (Note 2) 18 ms

DURATION COUNTER

Duration-Counter Resolution One tick 32 ms

Duration-Counter Range MSB is overflow bit 0 127 Counts

Duration-Counter Accuracy ±20 %

DIGITAL INPUTS (SDA, SCL, SHDN, A0, A1)

Input High Voltage V

Input Low Voltage V

Input Leakage Current IIH, I

Input Hysteresis 9%V

Input Capacitance 10 pF

LPWS

Time required for detection of key release
and final time duration to be stored in FIFO

IH

IL

IL

0.7 x
V

DD

-10 +10 µA

18 ms

V

0.3 x
V

DD

V

DD

MAX11041/MAX11042

Wired Remote Controllers

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +1.6V to 3.6V, C

SENSE

= 10nF, R

SENSE

= 10kΩ, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

____________________________________________________________________________________ 3

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DIGITAL OUTPUTS (SDA, INT)

Output High Voltage (INT)VOHI

Output Low Voltage (INT)V

Output High Leakage Current

Output Low Voltage (SDA) V

I2C TIMING CHARACTERISTICS (see Figure 1)

Serial Clock Frequency f

Bus Free Time Between STOP
and START Conditions

Hold Time (Repeated) START
Condition

SCL Pulse-Width Low t

SCL Pulse-Width High t

Setup Time for a Repeated
START Condition

Data Hold Time t

Data Setup Time t

SDA and SCL Receiving Rise
Time

SDA and SCL Receiving Fall
Time

SDA Transmitting Rise Time t

SDA Transmitting Fall Time t

Setup Time for STOP Condition t

Bus Capacitance C

Pulse Width of Suppressed Spike t

OLINTISINK

I

OHL

OLSDA

SCL

t

BUF

t

HD,STA

LOW

HIGH

t

SU,STA

HD,DAT

SU,DAT

t

RR

t

FR

RT

FT

SU,STO

b

SP

≤ 2mA

SOURCE

≤ 2mA

V

= V

OUT

DD

IOL = 3mA for VDD > 2V 0.4 V

IOL = 3mA for VDD < 2V

(Note 3)

(Note 3)

VDD = 3.6V (Note 3)

VDD = 2.4V to 3.6V

VDD = 1.6V to 2.4V

0.9 x
V

DD

0.1 x
V

DD

1µA

0.2 x
V

DD

0 400 kHz

1.3 µs

0.6 µs

1.3 µs

0.6 µs

0.6 µs

0 900 ns

100 ns

20 +

C

b

20 +

C

b

20 +

C

b

20 +

C

b

20 +
C

b

/ 10

/ 10

/ 10

/ 20

/ 20

300 ns

300 ns

250 ns

250

375

0.6 µs

400 pF

050ns

V

V

V

ns

MAX11041/MAX11042

Wired Remote Controllers

4 _______________________________________________________________________________________

Note 1: Recommended properties of external switch for proper detection of 30 keys or key combinations.
Note 2: See the Jack Insertion/Removal Detection section.
Note 3: C

b

is the bus capacitance in pF.

Note 4: Key current depends on external key resistors and is calculated by V

DD

/ (30.1kΩ + RSW).

Figure 1. I

2

C Serial-Interface Timing

ELECTRICAL CHARACTERISTICS (continued)

(VDD= +1.6V to 3.6V, C

SENSE

= 10nF, R

SENSE

= 10kΩ, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLIES

Power-Supply Voltage V

Average Operational Supply
Current

Shutdown Power-Supply Current I

Jack Current I

Key Current I
SHDN High to Part Active Wake-up time 5 ms

DDBUTTON

DD

I

DDOP

DDSHDN

DDJACK

1.6 3.6 V

Excluding jack/key current 5 20

Jack inserted, R

= 619kΩ 8

JACK

Excluding jack/key current 1 µA

Flowing when jack is inserted 4 µA

Flowing when keys pressed (Note 4) 90 µA

µA

START CONDITION

(S)

SDA

t

HIGH

t

t

SU,DAT

HD,DAT

t

RR

SCL

t

HD,STA

REPEAT START CONDITION

t

SU,STA

t

FR

t

(Sr)

LOW

t

HD,STA

t

RR,tRT

t

SU,STO

STOP CONDITION

t

FR,tFT

(P)

t

BUF

START CONDITION

(S)

MAX11041/MAX11042

Wired Remote Controllers

Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

____________________________________________________________________________________ 5

*Oscilloscope shots are taken with simulated bounce and chatter. Real switches will exhibit different bounce and chatter characteristics.

DEBOUNCE SCOPE SHOT (FALLING)

MAX11041/42 TOC01

V

SENSE

10ms/div

µ

P READS FIFO

INT

DEBOUNCED KEY
ADDED TO FIFO

VDD SUPPLY CURRENT vs. VOLTAGE

7.0
NO JACK INSERTED

6.5

TA = +85°C

6.0

V

DEBOUNCE SCOPE SHOT (RISING)

SENSE

INT

DEBOUNCE KEY ADDED

TO FIFO

10ms/div

MAX11041/42 TOC04

MAX11041/42 TOC02

µ

P READS

FIFO

VDD SHUTDOWN SUPPLY CURRENT

vs. VOLTAGE

1.00
NO JACK INSERTED

0.75

KEYPRESS RELEASE SCOPE SHOT*

V

SENSE

INT

DEBOUNCE KEY ADDED

TO FIFO

10ms/div

MAX11041/42 TOC05

MAX11041/42 TOC03

µ

P READS

FIFO

(µA)

5.5

DD

I

5.0

4.5

4.0

TA = +25°C

TA = -40°C

1.6 2.62.1 3.1 3.6
VDD (V)

(µA)

0.50

DD

I

0.25

0

1.6 2.62.1 3.1 3.6

TA = +85°C

TA = -40°C

TA = +25°C

VDD (V)

MAX11041/MAX11042

Detailed Description

The MAX11041/MAX11042 wired remote controllers
recognize either six or 30 different keypresses consist­ing of a resistor/switch array over a single connector.
Designed for wired remote controllers on the head­phone or headset cord, the MAX11041/MAX11042
contain debouncing circuitry and jack insertion/
removal detection. During a keypress, the MAX11041/
MAX11042 store the key type and key duration in an 8­word FIFO and INT (interrupt output) goes low. The
results stored in the FIFO are accessed through the I2C
interface.

FORCE and SENSE

During a keypress, a unique external resistor (R

SW_

)
located in the remote controller connects SENSE to
ground (Figure 2). This event changes the impedance

seen by the SENSE line. The MAX11041/MAX11042
decode this resistor value to an 8-bit result (see the
Required Resistor Set section). FORCE and SENSE are
±15kV ESD (IEC 61000-4-2) protected.

Register Description

The MAX11041/MAX11042 contain one 8-bit control
register, an 8-word FIFO (each word consists of an 8­bit key value and an 8-bit duration value), and an 8-bit
chip ID.

Chip ID

The chip ID identifies the features and capabilities of the
wired remote controller to the software. For the
MAX11041, the chip ID is 0x00. For the MAX11042, the
chip ID is 0x01.

Control Register

The MAX11041/MAX11042 contain one control register
(see Table 1). Bits C7, C6, and C5 control software shut­down. Set FORCE high-impedance and indicate if the
FIFO is empty. Write/read to the control register through
the I2C-compatible serial interface (see the Digital Serial
Interface section).

FIFO

The MAX11041/MAX11042 contain an 8-word FIFO that
can hold enough information for four keypresses and
releases. Each keypress and release results in two data
words being stored into the FIFO. Each FIFO word con­sists of 2 bytes. The 1st byte is the decoded keypress or
release (K7–K0) and the 2nd byte is the keypress or
release duration time. Table 2 shows the format of a key­press entry into the FIFO. Read the FIFO through the I2C­compatible serial interface (see the Digital Serial
Interface section). At power-up, all the FIFO is reset such
that K7–K0 are set to 0xFF hex and 0x0F, and T6–T0 are
set to 0x00. See the Applications Information section for
an example of how data is entered into the FIFO.

Wired Remote Controllers

6 _______________________________________________________________________________________

Pin Description

PIN

TQFN UCSP

1 D1 GND Ground

2 C1 SENSE

3, 11 B1, D3 V

4 A1 N.C. No Connection. Leave unconnected or connect to VDD.

5A2A1I

6A3A0I

7A4SHDN

8 B4 SCL I2C Serial-Interface Clock Input. SCL requires a pullup resistor.

9 C4 SDA I2C Serial-Interface Data Input/Output. SDA requires a pullup resistor.

10 D4 INT Active-Low Interrupt Output. INT goes low when a valid keypress is detected at SENSE.

12 D2 FORCE

EP — EP Exposed Pad. Connect EP to GND.

NAME FUNCTION

Voltage Sense Input. Connect SENSE to FORCE through an external lowpass filter

DD

composed of R
IEC61000-4-2 ESD protection on SENSE.

Power-Supply Input. Connect both VDD inputs together and bypass each VDD with a 0.1µF
capacitor to GND.

2

C Address Input 1. Logic state represents bit 1 of the I2C slave address.

2

C Address Input 0. Logic state represents bit 0 of the I2C slave address.

Active-Low Shutdown Input. Bring SHDN low to put the MAX11041/MAX11042 in shutdown
mode. FORCE is in a high-impedance state while SHDN is low.

Force Output. Connect FORCE to the external resistor array. Connect SENSE to FORCE
through an external lowpass filter composed of R
is a ±15kV IEC61000-4-2 ESD protection on FORCE.

SENSE

and C

(see the FORCE and SENSE section). There is a ±15kV

SENSE

= 10kΩ and C

SENSE

SENSE

= 10nF. There