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MAX7347ATE+T

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P29
General Description
The MAX7347/MAX7348/MAX7349 I
2
C interfaced periph-
erals provide microprocessors with management of up to
64 key switches. Key inputs are monitored statically, not
dynamically scanned, to ensure low-EMI operation. The
MAX7347 can monitor up to 24 switches, the MAX7348
can monitor up to 40 switches, and the MAX7349 can
monitor up to 64 switches. The switches can be metallic
or resistive (carbon) up to 1kΩ.
The key controller debounces and maintains a FIFO of
key-press events (including autorepeat, if enabled). An
interrupt (INT) output can be configured to alert key
presses either as they occur, or at maximum rate.
The MAX7348/MAX7349 feature a tone generator to
generate automatic key-click sounds or alarm tones
under processor control.
The sounder frequencies cover the 5th musical octave
(523.25Hz to 987.77Hz), plus seven other musical
notes up to 2637Hz. The output can also be pro-
grammed to be high or low for the sound duration to
operate an electronic sounder, relay, or lamp.
The MAX7347 is offered in 16-pin QSOP and TQFN
packages. The MAX7348 is offered in a 20-pin QSOP
package. The MAX7349 is available in 24-pin QSOP and
TQFN packages. The MAX7347/MAX7348/MAX7349
operate over the -40°C to +125°C temperature range.
Applications
Medical Instruments
Instrumentation Panels
Security and Access
Industrial Controls
Features
♦ 400kbps, 5.5V-Tolerant 2-Wire Serial Interface
♦ 2.4V to 3.6V Operation
♦ Monitor Up to 64 Keys (MAX7349),
40 Keys (MAX7348), or 24 Keys (MAX7347)
♦ FIFO Queues Up to 8 Debounced Key Events
♦ Key Debounce Time User Configurable from 9ms
to 40ms
♦ Key Autorepeat Rate and Delay User Configurable
♦ Low-EMI Design Uses Static Matrix Monitoring
♦ Hardware Interrupt on Each Debounced Event or
FIFO Level, or at End of Definable Time Period
♦ Up to Six Open-Drain Logic Outputs Available
Capable of Driving LEDs
♦ Sounder Output Generates Automatic Key Clicks
♦ 14 Programmable Musical Sounder Frequencies
♦ Continuous or Programmable Sounder Duration
♦ Easy Automatic Single-Tone and Dual-Tone Alarm
Sound Generation
♦ Four I
2
C Address Choices
♦ Selectable 2-Wire Serial Bus Timeout
♦ Under 10µA Shutdown Current
MAX7347/MAX7348/MAX7349
2-Wire Interfaced Low-EMI Key Switch
and Sounder Controllers
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
19-3556; Rev 5; 5/07
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.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE
PIN-
PACKAGE
PKG
CODE
MAX7347AEE+ -40°C to +125°C 16 QSOP
E16-4
MAX7347ATE+ -40°C to +125°C 16 TQFN-EP*
T1644-4
MAX7348AEP+ -40°C to +125°C 20 QSOP
E20-1
MAX7349AEG+ -40°C to +125°C 24 QSOP
E24-1
MAX7349ATG+ -40°C to +125°C 24 TQFN-EP*
T2444-4
+
Denotes lead-free package.
*
EP = Exposed paddle.
MAX7349
V+
COL_
SOUNDER
GND
8
SCL
SDA
AD0
ALERT
ROW_
8
PIEZO
TRANSDUCER
SWITCH
ARRAY, UP
TO 64
SWITCHES
INPUT
2.4V TO 3.6V
INT
Typical Application Circuit
Pin Configurations appear at end of data sheet.
MAX7347/MAX7348/MAX7349
2-Wire Interfaced Low-EMI Key Switch
and Sounder 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.
(All voltages referenced to GND.)
V+ ............................................................................-0.3V to +4V
COL2/PORT2–COL7/PORT7 ....................................-0.3V to +4V
SDA, SCL, AD0, ALERT, INT ....................................-0.3V to +6V
All Other Pins................................................-0.3V to (V+ + 0.3V)
DC Current on COL2/PORT2–COL7/PORT7 ......................25mA
DC Current on SOUNDER ................................................±25mA
GND Current .......................................................................80mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)...........666mW
16-Pin TQFN (derate 16.9mW/°C above +70°C).......1349.1mW
20-Pin QSOP (derate 9.1mW/°C above +70°C)...........727mW
24-Pin QSOP (derate 9.5mW/°C above +70°C)...........761mW
24-Pin TQFN (derate 20.8mW/°C above +70°C).......1666.7mW
Operating Temperature Range (T
MIN
to T
MAX
) ...-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(V+ = 2.4V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= +25°C.) (Notes 1, 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Operating Supply Voltage V+ 2.4 3.6 V
Operating Supply Current I+ All key switches open 75 100 µA
Shutdown Supply Current I
SH
6.44 10 µA
SOUNDER Output High Voltage V
OHBUZ
I
SOURCE
= 10mA
V+ -
0.45
V
SOUNDER Output Low Voltage V
OLBUZ
I
SINK
= 10mA 0.15 V
SOUNDER Frequency Accuracy T
A
= +25°C, V+ = 3.3V 1.2 %
Key-Switch Source Current I
KEY
28 40 µA
Key-Switch Source Voltage V
KEY
0.35 0.65 V
Key-Switch Resistance R
KEY
(Note 3) 1 kΩ
Startup Time from Shutdown t
START
57 200 µs
Output Low Voltage
COL2/PORT2 to COL7/PORT7,
INT Output
V
OLPORT
I
SINK
= 10mA 0.15 V
Input voltage ≤ V+ -1 +1
Input Leakage Current Alert
Input voltage > V+ -5 +5
µA
Input High Voltage ALERT V
IH
2.2 V
Input Low Voltage ALERT V
IL
0.8 V
SERIAL-INTERFACE SPECIFICATIONS
Serial Bus Timeout t
OUT
With bus timeout enabled 20 68 ms
Input High Voltage
SDA, SCL, AD0
V
IH
2.2 V
Input Low Voltage
SDA, SCL, AD0
V
IL
0.6 V
Input voltage ≤ V+ -1 +1
Input Leakage Current
SDA, SCL, AD0
Input voltage > V+ -5 +5
µA
MAX7347/MAX7348/MAX7349
2-Wire Interfaced Low-EMI Key Switch
and Sounder Controllers
_______________________________________________________________________________________ 3
I
2
C TIMING CHARACTERISTICS
(V+ = 2.4V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V+ = 3.3V, T
A
= +25°C.) (Notes 1, 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Capacitance
(SCL, SDA, AD0)
C
IN
(Notes 3, 4) 10 pF
With bus timeout enabled 0.05 400
SCL Serial Clock Frequency f
SCL
With bus timeout disabled 0 400
kHz
Bus Free Time Between a STOP
and a START Condition
t
BUF
1.3 µs
Hold Time (Repeated) START
Condition
t
HD
,
STA
0.6 µs
Repeated START Condition
Setup Time
t
SU
,
STA
0.6 µs
STOP Condition Setup Time t
SU
,
STO
0.6 µs
Data Hold Time t
HD
,
DAT
(Note 5) 0.9 µs
Data Setup Time t
SU
,
DAT
100 ns
SCL Clock Low Period t
LOW
1.3 µs
SCL Clock High Period t
HIGH
0.7 µs
Rise Time of Both SDA and SCL
Signals, Receiving
t
R
(Notes 3, 4)
20 +
0.1C
b
300 ns
Fall Time of Both SDA and SCL
Signals, Receiving
t
F
(Notes 3, 4)
20 +
0.1C
b
300 ns
Fall Time of SDA Transmitting t
F.TX
(Notes 3, 6)
20 +
0.1C
b
250 ns
Pulse Width of Spike Suppressed t
SP
(Notes 3, 7) 50 ns
Capacitive Load for Each Bus
Line
C
b
(Note 3) 400 pF
Note 1: All parameters are tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 2: All digital inputs at V+ or GND.
Note 3: Guaranteed by design.
Note 4: C
b
= total capacitance of one bus line in pF. t
R
and t
F
measured between 0.8V and 2.1V.
Note 5: A master device must provide a hold time of at least 300ns for the SDA signal (referred to V
IL
of the SCL signal) to bridge
the undefined region of SCL’s falling edge.
Note 6: I
SINK
≤ 6mA. C
b
= total capacitance of one bus line in pF. t
R
and t
F
measured between 0.8V and 2.1V.
Note 7: Input filters on the SDA, SCL, and AD0 inputs suppress noise spikes less than 50ns.
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P27P28-P29

MAX7347ATE+T

Mfr. #:
Buy MAX7347ATE+T
Manufacturer:
Maxim Integrated
Description:
Interface - Specialized Low-EMI Key Switch & Sounder Controller
Lifecycle:
New from this manufacturer.
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