DAC1282 - Low Distortion Digital-to-Analog Converter for Seismic Applications

The DAC1282 is a fully-integrated digital-to-analog converter (DAC) providing low distortion, digital synthesized voltage output suitable for testing of seismic equipment. The DAC1282 achieves very high performance in a small package with low power. Together, with the high-performance ADS1281 and ADS1282 analog-to-digital converters (ADCs), these devices create a measurement system that meets the exacting demands of seismic data acquisition equipment.

The DAC1282 integrates a digital signal generator, a DAC, and an output amplifier providing sine wave, dc, and pulse output voltages.

The output frequency is programmable from 0.5 Hz to 250 Hz and the magnitude is scaled by both analog and digital control. The analog gain is adjustable in 6-dB steps and the digital gain in 0.5-dB steps. The analog gain settings match those of the ADS1282 for testing at all gains with high resolution.

The DAC1282 also provides pulse outputs. The pulse amplitude is user-programmed and then selected by the pin for precise timing. Custom output signals can be generated by applying an external bitstream pattern.

A signal switch can be used to connect the DAC output to sensors for THD and impulse testing. The switch timing is controlled by pin and by command.

A SYNC pin synchronizes the DAC output to the analog-to-digital converter (ADC) sample interval. A power-down input disables the device, reducing power consumption to microwatts.

• Single-Chip Test Signal Generator
• Buffered Voltage Output
• High Performance:
  • THD: –125 dB (G = 1/1 to 1/8)
  • SNR: 120 dB (413 Hz BW, G = 1/1)
• Analog and Digital Gain Control
• Output Frequency: 0.488 Hz to 250 Hz
• Sine, Pulse, and DC Modes
• Digital Data Input Mode
• Low On-Resistance Signal Switch
• Sync Input
• Power-Down Mode
• Analog Supply: 5 V or ±2.5 V
• Digital Supply: 1.8 V to 3.3 V
• Power: 38 mW
• Package: TSSOP-24
• Operating Range: –50°C to +125°C