ICs Tightly Control LED Display Brightness

Interfacing microprocessors to LEDs or LED displays via a 2-wire, I2C-compatible serial interface, the MAX6958/6959 common-cathode LED display drivers are said to be the first such devices to offer keyscan and 64-step digital brightness control capabilities. The MAX6959 can also automatically scan and debounce a matrix of up to eight switches. Well-suited for use on front panels, the ICs can drive four 7-segment digits and eight discrete LEDs, or four 7-segment digits with decimal point and four LEDs (about 4.5 digits), or 36 LEDs. Besides segment and digit drivers, the devices also have a hexadecimal character decoder (0-9, A-F) and SRAM for storing each digit. Both drivers can operate from a 3V to 5.5V supply and offer a low-power shutdown mode. In 16-pin QSOPs and DIPs, the MAX6958 costs from $3.33 each/1,000 and the MAX6959, $4.40. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.