MAX6954 4-Wire Interfaced, 2.7V to 5.5V LED Display Driver with I/O Expander and Key Scan General Description Features The MAX6954 is a compact display driver that inter- High-Speed 26MHz SPI/QSPI/MICROWIRE - faces microprocessors to a mix of 7-segment, 14-seg- Compatible Serial Interface ment, and 16-segment LED displays through an SPI-/ 2.7V to 5.5V Operation QSPI-compatible 4-wire serial interface. The serial Drives Up to 16 Digits 7-Segment, 8 Digits interface may be cascaded through multiple devices. 14-Segment, 8 Digits 16-Segment, 128 Discrete The MAX6954 drives up to 16 digits 7-segment, 8 dig- LEDs, or a Combination of Digit Types its 14-segment, 8 digits 16-segment, or 128 discrete LEDs, while functioning from a supply voltage as low as Drives Common-Cathode Monocolor and Bicolor LED 2.7V. The driver includes five I/O expander (or GPIO) Displays lines, some or all of which may be configured as Built-In ASCII 104-Character Font for 14-Segment a key-switch reader, which automatically scans and and 16-Segment Digits and Hexadecimal Font for debounces a matrix of up to 32 switches. 7-Segment Digits Included on chip are full 14- and 16-segment ASCII Automatic Blinking Control for each Segment 104-character fonts, a hexadecimal font for 7-segment 10A (typ) Low-Power Shutdown (Data Retained) displays, multiplex scan circuitry, anode and cathode driv- ers, and static RAM that stores each digit. The maximum 16-Step Digit-by-Digit Digital Brightness Control segment current for the display digits is set using a single Display Blanked on Power-Up external resistor. Digit intensity can be independently Slew-Rate Limited Segment Drivers for Lower EMI adjusted using the 16-step internal digital brightness con- trol. The MAX6954 includes a low-power shutdown mode, Five GPIO Port Pins Can Be Configured as Key- a scan-limit register that allows the user to display from 1 Switch Reader to Scan and Debounce Up to 32 to 16 digits, segment blinking (synchronized across mul- Switches with n-Key Rollover tiple drivers, if desired), and a test mode, which forces all IRQ Output when a Key Input Is Debounced LEDs on. The LED drivers are slew-rate limited to reduce 36-Pin SSOP and 40-Pin DIP and TQFN Packages EMI. Automotive Temperature Range Standard For a 2-wire interfaced version, refer to the MAX6955 data sheet. An evaluation kit (EV kit) for the MAX6955 is Functional Diagram available. P0 TO P4 GPIO AND KEY-SCAN Applications CONTROL Set-Top Boxes Bar Graph Displays CURRENT PWM ISET O0 TO O23 BRIGHTNESS SOURCE LED CONTROL Panel Meters Audio/Video Equipment DRIVERS DIGIT White Goods OSC MULTIPLEXER DIVIDER/ COUNTER NETWORK OSC OUT CHARACTER Ordering Information GENERATOR MAX6954 ROM PART TEMP RANGE PIN-PACKAGE BLINK BLINK MAX6954AAX -40C to +125C 36 SSOP CONTROL MAX6954APL -40C to +125C 40 PDIP CONFIGURATION REGISTER RAM MAX6954ATL+ -40C to +125C 40 TQFN-EP* CLK +Denotes a lead-free/RoHS-compliant package. CS 4-WIRE SERIAL INTERFACE *EP = Exposed pad. DIN DOUT QSPI is a trademark of Motorola, Inc. Pin Configurations and Typical Operating Circuits appear MICROWIRE is a registered trademark of National at end of data sheet. Semiconductor Corp. 19-2460 Rev 5 7/14MAX6954 4-Wire Interfaced, 2.7V to 5.5V LED Display Driver with I/O Expander and Key Scan Absolute Maximum Ratings (Voltage with respect to GND.) Continuous Power Dissipation (T = +70C) A V+ ........................................................................-0.3V to +6V 36-Pin SSOP (derate at 11.8mW/C above +70C) ....941mW All Other Pins...........................................-0.3V to (V+ + 0.3V) 40-Pin PDIP (derate at 16.7mW/C above +70C) ...1333mW Current 40-Pin TQFN (derate at 37mW/C above +70C) .....2963mW O0O7 Sink Current .....................................................935mA Operating Temperature Range O0O18 Source Current.................................................55mA (T to T ) ............................................. -40C to +125C MIN MAX DIN, CLK, CS, OSC, DOUT, BLINK, OSC OUT, ISET ..20mA Junction Temperature ......................................................+150C P0, P1, P2, P3, P4 .........................................................40mA Storage Temperature Range ............................ -65C to +150C GND .....................................................................................1A 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. DC Electrical Characteristics (Typical Operating Circuits, V+ = 2.7V to 5.5V, T = T to T , unless otherwise noted.) (Note 1) A MIN MAX PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Operating Supply Voltage V+ 2.7 5.5 V Shutdown mode, all T = +25C 10 35 A Shutdown Supply Current I digital inputs at V+ A SHDN or GND T = T to T 40 A MIN MAX All segments on, all digits scanned, intensity set to full, T = +25C 22 30 A internal oscillator, Operating Supply Current I+ mA DOUT open circuit, no display or OSC OUT load connected T = T to T 35 A MIN MAX OSC = RC oscillator, R = 56kW, SET 4 C = 22pF, V+ = 3.3V SET Master Clock Frequency f MHz OSC OSC driven externally 1 8 Dead Clock Protection Frequency f 95 kHz OSC OSC Internal/External Detection V 1.7 V OSC Threshold OSC High Time t 50 ns CH OSC Low Time t 50 ns CL OSC = RC oscillator, R = 56kW, SET Slow Segment Blink Period f 1 s SLOWBLINK C = 22pF, V+ = 3.3V SET OSC = RC oscillator, R = 56kW, SET Fast Segment Blink Period f 0.5 s FASTBLINK C = 22pF, V+ = 3.3V SET Fast or Slow Segment Blink Duty 49.5 50.5 % Cycle Maxim Integrated 2 www.maximintegrated.com