MAX6958

400kbps 2-Wire Serial Interface
3V to 5.5V Operation
Drive 4 Digits plus 4 or 8 Discrete LEDs
Drive Common-Cathode LED Digits
23mA Constant-Current LED Segment Drive
Hexadecimal Decode/No-Decode Digit Selection
64-Step Digital Brightness Control
Slew-Rate-Limited Segment Drivers Reduced EMI
Debounces Up to Eight Switches with n-Key Rollover (MAX6959 Only)
IRQ Output When a Key Input Is Debounced (MAX6959 Only)
20A Low-Power Shutdown (Data Retained)
Automotive Temperature Range (-40°C to +125°C)
Compact 16-Pin PDIP and QSOP Packages

Voltage (with respect to GND)
      V+, SCL, SDA .......................................................-0.3V to +6V
      All Other Pins............................................-0.3V to (V+ + 0.3V)
Current
      DIG0/SEG0DIG3/SEG3 Sink Current ...........................275mA
      DIG0/SEG0SEG9 Source Current ..................................30mA
      SCL, SDA, INPUT1, INPUT2 ..............................................20mA
Continuous Power Dissipation (TA = +70°C)
      16-Pin DIP (derate at 10.5mW/°C above +70°C).........842mW
      16-Pin QSOP (derate at 8.34mW/°C above +70°C).....667mW
Operating Temperature Range
      MAX695_ (TMIN to TMAX) ..............................-40°C to +125°C
Junction Temperature..........................................................+150°C
Storage Temperature Range ...............................-65°C to +150°C
Lead Temperature (soldering, 10s) .....................................+300°C

The MAX6958/MAX6959 compact multiplexed common- cathode display drivers interface microprocessors to seven-segment numeric LED digits, or discrete LEDs through an SMBus™- and I2C-compatible 2-wire serial interface. The 2-wire serial interface of MAX6958 uses fixed 0.8V/2.1V logic thresholds for compatibility with 2.5V and 3.3V systems when the display driver is powered from a 5V supply.

The MAX6958/MAX6959 drive up to four 7-segment digits, with decimal points, plus four discrete LEDs, or four 7-segment digits and eight discrete LEDs if the digits' decimal points are not used, or up to 36 discrete LEDs. The MAX6959 also includes two input ports, one or both of which may be configured as a key-switch reader, which automatically scans and debounces a matrix of up to eight switches. Key-switch status is obtained by polling internal status registers or by configuring the MAX6959 interrupt output.

Other on-chip features include a hexadecimal font for seven-segment displays, multiplex scan circuitry, anode and cathode drivers, and static RAM that stores each digit. The peak segment current for the display digits is set internally to 23mA. Display intensity is adjusted using a 64-step internal digital brightness control. The MAX6958/MAX6959 include a low-power shutdown mode, a scan-limit register that allows the user to display from one to four digits, and a test mode, which forces all LEDs on. The LED drivers are slew-rate-limited to reduce EMI. The MAX6958/MAX6959 are available in 16-pin PDIP and QSOP packages and are fully specified over the -40°C to +125°C automotive temperature range.