MAX6946

19-0598; Rev 0; 7/06 10-Port, Constant-Current LED Drivers and I/O Expanders with PWM Intensity Control General Description The MAX6946/MAX6947 I2C*-/SMBus TM-compatible, serial-interfaced peripherals provide microprocessors with 10 I/O ports rated to 7V. Each port can be configured as a 2.5mA to 20mA constant-current LED driver (static or PWM), a 1.25mA to 10mA constant-current LED driver (static or PWM), an open-drain logic output, or an overvoltage-protected Schmitt logic input. Analog and switching LED intensity control includes indiwww.DataSheet4U.com vidual 8-bit PWM control per output, individual 1-bit analog current control (half/full scale) per output, and a global 3-bit DAC current control that applies to all LED outputs. The MAX6946/MAX6947 can stagger the PWM timing of the 10-port outputs in consecutively phased 45° increments. Staggering the outputs spreads the PWM load currents over time in eight steps, helping to even out the power-supply current and reduce the RMS current. For a similar part with a SPITM-/QSPITM-/ or MICROWIRETMcompatible interface, refer to the MAX6966/MAX6967 data sheet. Features ♦ 400kb, 6V-Tolerant Serial Interface ♦ 2.25V to 3.6V Operation ♦ I/O Ports Default to High Impedance (LEDs Off) on Power-Up ♦ I/O Port Inputs Are Overvoltage Protected to 7V ♦ I/O Port Outputs Are 7V-Rated Open-Drain, 10mA or 20mA Constant-Current Static/PWM LED Drivers, or Open-Drain Logic Outputs ♦ I/O Ports Support Hot Insertion ♦ Individual 8-Bit PWM Intensit...