MC14489B数据手册恩XP中文资料规格书

描述 Description

Overview The MC14489B is a flexible light-emitting-diode driver which directly interfaces to individual lamps, 7-segment displays, or various combinations of both. LEOs wired with common cathodes are driven in a multiplexed-by-5 fashion. Communication with an MCUIMPU is established through a synchronous serial port. The MC 14489B 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 anyone of the following: a 5-digit display plus decimals, a 4-112-digit display plus decimals and sign, or 25 lamps.A special technique allows driving 5 112 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 O to 9, hexadecimal characters A to F, plus 15 1etters and symbols. The MC14489B is compatible with the NXP® SPI and National MI-CRO-WIRETM serial data ports. The chip's patented BitGrabberTM registers augment the serial interface by allowing random access without steering or address bits.A 24-bit transfer updates the display register. Changing the configuration register requires an 8-bit transfer.

特性 Features

•Operating Voltage Range of Drive Circuitry: 4.5 to 5.5 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 EMIin 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.)