Multi-Character LED Display/Lamp Driver

CMOS

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.

• Operating Voltage Range of Drive Circuitry: 4.5 to 6 V

• Operating Junction Temperature Range: – 40°to 130°C

• Current Sources Controlled by Single Resistor Provide Anode Drive

• Low–Resistance FET Switches Provide Direct Common Cathode Interface

• Low–Power Mode (Extinguishes the LEDs) and Brightness Controlled via Serial Port

• Special Circuitry Minimizes EMI when Display is Driven and Eliminates EMI in Low–Power Mode

• Power–On Reset (POR) Blanks the Display on Power–Up, Independent of Supply Ramp Up Time

• May Be Used with Double–Heterojunction LEDs for Optimum Efficiency

• Chip Complexity: 4300 Elements (FETs, Resistors, Capacitors, etc.)

• See Application Note AN431, Temperature Measurement and Display Using the MC68HC05B4 and the MC14489and Engineering Bulletin EB153, Driving a Seven–Segment Display with the NEURONCHIP