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.