1FEATURES
2• Outstanding Performance:
– THD: –125dB
– SNR: 120dB (413Hz BW, Gain = 1/1)
– Gain Error: 0.1%
• Pin Operation: No Registers to Program
• Gain: 1/1 to 1/64
• SYNC Input for Phase Control
• Power-Down Mode
• Low Power: 18mW
• Analog Supply: +5V or ±2.5V
• Digital Supply: 1.8V to 3.3V
• Small 16-Pin TSSOP Package
• Temperature Range: –40°C to +85°C

APPLICATIONS
• Energy Exploration Equipment
• Seismic Monitoring Systems

DESCRIPTION
The DAC1280 is a very low distortion digital-to-analog
converter (DAC) suited for performance testing of
seismic equipment. The DAC1280 provides a
high-accuracy output signal from a bitstream input.
The device achieves very high linearity in a small
package while dissipating only 18mW. Together with
the high-performance ADS1281 and ADS1282
analog-to-digital converters (ADCs), these devices
create a test and measurement system that meets
the exacting demands of energy exploration and
seismic monitoring equipment.
The DAC1280 is designed to match the system
components (power supply, clock and reference
voltage) of the companion ADCs, the ADS1281 and
ADS1282. The input to the DAC1280 is a 1s density
modulated bitstream. The DAC1280 output is a
differential current intended for use with an active I/V
converter. The I/V converter provides a voltage output
suitable for performance testing of sensors and
ADCs.
Three gain control pins set the output range in 6dB
steps from 0dB to –36db (±2.5V to ±0.039V
differential). The attenuation ranges match the gains
of the ADS1282 for testing at all gains. The DAC
uses a reference voltage and bias resistor to set the
full-scale output. The resistor can be adjusted to
fine-trim the DAC full-scale.
The SYNC pin aligns the input data sampling to the
CLK phase. A power-down pin shuts down the device
when not in use. The DAC1280 is available in a
small, 16-pin TSSOP package and is fully specified
for operation over –40°C to +85°C temperature range
with a maximum operating temperature of +125°C.