The MC14489 is a flexible light–emitting–diode driver which directly interfaces to individual lamps, 7–segment displays, or various combinations of both. LEDs wired with common cathodes are driven in a multiplexed–by–5 fashion. Communication with an MCU/MPU is established through a synchronous serial port. The MC14489 features data retention plus decode and scan circuitry, thus relieving processor overhead. A single, current–setting resistor is the only ancillary component required. A single device can drive any one of the following: a 5–digit display plus decimals, a 4–1/2–digit display plus decimals and sign, or 25 lamps. A special technique allows driving 5 1/2 digits; see Figure 16. A configuration register allows the drive capability to be partitioned off to suit many additional applications. The on–chip decoder outputs 7–segment–format numerals 0 to 9, hexadecimal characters A to F, plus 15 letters and symbols.
Download:
