A6818

The A6818- devices combine a 32-bit CMOS shift register, accompanying data latches and control circuitry with bipolar sourcing outputs and pnp active pull downs. Designed primarily to drive vacuum- fluorescent displays, the 60 V and -40 mA output ratings also allow these devices to be used in many other peripheral power driver applications. The A6818- features an increased data input rate (compared with the older UCN/UCQ5818-F>) and a controlled output slew rate.

The CMOS shift register and latches allow direct interfacing with microprocessor-based systems. With a 3.3 V or 5 V logic supply, typical serial-data input rates are up to 33 MHz.

A CMOS serial data output permits cascade connections in applications requiring additional drive lines. Similar devices are available as the A6810- (10 bits), A6811- (12 bits), and A6812- (20 bits).

The A6818- output source drivers are npn Darlingtons, capable of sourcing up to 40 mA. The controlled output slew rate reduces electro- magnetic noise, which is an important consideration in systems that include telecommunications and/or microprocessors and to meet government emissions regulations. For inter-digit blanking, all output drivers can be disabled and all sink drivers turned on with a BLANKING input high. The pnp active pull-downs will sink at least 2.5 mA.