8-Bit, Octal, 4-Quadrant Multiplying, CMOS TrimDAC

The DAC-8840 provides eight general purpose digitally controlled voltage adjustment devices. The TrimDAC® capability allows replacement of the mechanical trimmer function in new designs. The DAC-8840 is ideal for ac or dc gain control of up to 1 MHz bandwidth signals. The 4-quadrant multiplying capability is useful for signal inversion and modulation often found in video convergence circuitry.

Internally the DAC-8840 contains eight voltage output CMOS digital-to-analog converters, each with separate reference inputs. Each DAC has its own DAC register which hold its output state. These DAC registers are updated from an internal serial-to-parallel shift register which is loaded from a standard 3-wire serial input digital interface. Twelve data bits make up the data word clocked into the serial input register. This data word is decoded where the first 4 bits determine the address of the DAC register to be loaded with the last 8 bits of data. A serial data output pin at the opposite end of the serial register allows simple daisy-chaining in multiple DAC applications without additional external decoding logic.

The DAC-8840 consumes only 190 mW from ±5 V power supplies. For single 5 V supply applications consult the DAC-8841.

The DAC-8840 is available in 24-pin plastic DIP, cerdip, and SOIC-24 packages.

* Replaces 8 Potentiometers

* 1 MHz 4-Quadrant Multiplying Bandwidth

* No Signal Inversion

* Low Zero Output Error

* Eight Individual Channels