MAX7347/MAX7348/MAX7349 19-3556 Rev 5 5/07 2-Wire Interfaced Low-EMI Key Switch and Sounder Controllers General Description Features 2 The MAX7347/MAX7348/MAX7349 I C interfaced periph- 400kbps, 5.5V-Tolerant 2-Wire Serial Interface erals provide microprocessors with management of up to 2.4V to 3.6V Operation 64 key switches. Key inputs are monitored statically, not dynamically scanned, to ensure low-EMI operation. The Monitor Up to 64 Keys (MAX7349), MAX7347 can monitor up to 24 switches, the MAX7348 40 Keys (MAX7348), or 24 Keys (MAX7347) can monitor up to 40 switches, and the MAX7349 can FIFO Queues Up to 8 Debounced Key Events monitor up to 64 switches. The switches can be metallic or resistive (carbon) up to 1k. Key Debounce Time User Configurable from 9ms The key controller debounces and maintains a FIFO of to 40ms key-press events (including autorepeat, if enabled). An Key Autorepeat Rate and Delay User Configurable interrupt (INT) output can be configured to alert key presses either as they occur, or at maximum rate. Low-EMI Design Uses Static Matrix Monitoring The MAX7348/MAX7349 feature a tone generator to Hardware Interrupt on Each Debounced Event or generate automatic key-click sounds or alarm tones FIFO Level, or at End of Definable Time Period under processor control. Up to Six Open-Drain Logic Outputs Available The sounder frequencies cover the 5th musical octave Capable of Driving LEDs (523.25Hz to 987.77Hz), plus seven other musical notes up to 2637Hz. The output can also be pro- Sounder Output Generates Automatic Key Clicks grammed to be high or low for the sound duration to 14 Programmable Musical Sounder Frequencies operate an electronic sounder, relay, or lamp. Continuous or Programmable Sounder Duration The MAX7347 is offered in 16-pin QSOP and TQFN packages. The MAX7348 is offered in a 20-pin QSOP Easy Automatic Single-Tone and Dual-Tone Alarm package. The MAX7349 is available in 24-pin QSOP and Sound Generation TQFN packages. The MAX7347/MAX7348/MAX7349 2 operate over the -40C to +125C temperature range. Four I C Address Choices Selectable 2-Wire Serial Bus Timeout Applications Medical Instruments Under 10A Shutdown Current Instrumentation Panels Security and Access Ordering Information Industrial Controls PKG PIN- PART TEMP RANGE CODE Pin Configurations appear at end of data sheet. PACKAGE E16-4 MAX7347AEE+ -40C to +125C 16 QSOP Typical Application Circuit T1644-4 MAX7347ATE+ -40C to +125C 16 TQFN-EP* E20-1 MAX7348AEP+ -40C to +125C 20 QSOP INPUT 2.4V TO 3.6V E24-1 MAX7349AEG+ -40C to +125C 24 QSOP 8 MAX7349 V+ COL SWITCH T2444-4 MAX7349ATG+ -40C to +125C 24 TQFN-EP* ARRAY, UP TO 64 +Denotes lead-free package. 8 SWITCHES ROW *EP = Exposed paddle. SCL SDA PIEZO ALERT TRANSDUCER INT AD0 SOUNDER GND Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE2-Wire Interfaced Low-EMI Key Switch and Sounder Controllers ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) Continuous Power Dissipation (T = +70C) A V+ ............................................................................-0.3V to +4V 16-Pin QSOP (derate 8.3mW/C above +70C)...........666mW COL2/PORT2COL7/PORT7 ....................................-0.3V to +4V 16-Pin TQFN (derate 16.9mW/C above +70C).......1349.1mW SDA, SCL, AD0, ALERT, INT....................................-0.3V to +6V 20-Pin QSOP (derate 9.1mW/C above +70C)...........727mW All Other Pins................................................-0.3V to (V+ + 0.3V) 24-Pin QSOP (derate 9.5mW/C above +70C)...........761mW DC Current on COL2/PORT2COL7/PORT7 ......................25mA 24-Pin TQFN (derate 20.8mW/C above +70C).......1666.7mW DC Current on SOUNDER ................................................25mA Operating Temperature Range (T to T ) ...-40C to +125C MIN MAX GND Current .......................................................................80mA Junction Temperature......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C 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+ = 2.4V to 3.6V, T = T to T , unless otherwise noted. Typical values are at V+ = 3.3V, T = +25C.) (Notes 1, 2) A MIN MAX A 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 A Shutdown Supply Current I 6.44 10 A SH V+ - SOUNDER Output High Voltage V I = 10mA V OHBUZ SOURCE 0.45 SOUNDER Output Low Voltage V I = 10mA 0.15 V OLBUZ SINK SOUNDER Frequency Accuracy T = +25C, V+ = 3.3V 1.2 % A Key-Switch Source Current I 28 40 A KEY Key-Switch Source Voltage V 0.35 0.65 V KEY Key-Switch Resistance R (Note 3) 1 k KEY Startup Time from Shutdown t 57 200 s START Output Low Voltage COL2/PORT2 to COL7/PORT7, V I = 10mA 0.15 V OLPORT SINK INT Output Input voltage V+ -1 +1 Input Leakage Current Alert A Input voltage > V+ -5 +5 Input High Voltage ALERT V 2.2 V IH Input Low Voltage ALERT V 0.8 V IL SERIAL-INTERFACE SPECIFICATIONS Serial Bus Timeout t With bus timeout enabled 20 68 ms OUT Input High Voltage V 2.2 V IH SDA, SCL, AD0 Input Low Voltage V 0.6 V IL SDA, SCL, AD0 Input voltage V+ -1 +1 Input Leakage Current A SDA, SCL, AD0 Input voltage > V+ -5 +5 2 MAX7347/MAX7348/MAX7349