GENERAL DESCRIPTION
The AD7801 is a single, 8-bit, voltage out DAC that operates from a single +2.7 V to +5.5 V supply. Its on-chip precision output buffer allows the DAC output to swing rail to rail. The AD7801 has a parallel microprocessor and DSP compatible interface with high speed registers and double buffered interface logic. Data is loaded to the input register on the rising edge of CS or WR. Reference selection for the AD7801 can be either an internal reference derived from the VDD or an external reference applied at the REFIN pin. The output of the DAC can be cleared by using the asynchronous CLR input. The low power consumption of this part makes it ideally suited to portable battery operated equipment. The power consumption is less than 5 mW at 3.3 V, reducing to less than 3 µW in power-down mode.

PRODUCT HIGHLIGHTS
1. Low Power, Single Supply operation. This part operates from a single +2.7 V to +5.5 V supply and consumes typically 5 mW at 3 V, making it ideal for battery powered applications.
2. The on-chip output buffer amplifier allows the output of the DAC to swing rail to rail with a settling time of typically 1.2 µs.
3. Internal or external reference capability.
4. High speed parallel interface.
5. Power-down capability. When powered down the DAC consumes less than 1 µA at 25°C.
6. Packaged in 20-lead SOIC and TSSOP packages.

FEATURES
Single 8-Bit DAC
20-Pin SOIC/TSSOP Package
+2.7 V to +5.5 V Operation
Internal and External Reference Capability
DAC Power-Down Function
Parallel Interface
On-Chip Output Buffer Rail-to-Rail Operation
Low Power Operation 1.75 mA max @ 3.3 V
Power-Down to 1 mA max @ 258C

APPLICATIONS
Portable Battery Powered Instruments
Digital Gain and Offset Adjustment
Programmable Voltage and Current Sources
Programmable Attenuators