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18-bit DAC offers DC and AC accuracy benefits

Linear Technology Corporation has introduced what the company claims is the industry's first 18-bit digital-to-analog converter (DAC) to offer precision DC specifications of ±1LSB INL (max) and ±1LSB DNL (max).

The LTC2757 is 18-bit accurate over a ±10 V output range, offering a full-scale settling time of 2.1 μs and low 1.4 nV.s glitch impulse. Fast settling and low glitch reduce harmonic distortion, making it possible to produce higher frequency, lower noise output waveforms. The combination of DC and AC accuracy will enable the design of higher performance instrumentation, automated test equipment, data acquisition systems, and medical devices.

Six unique output voltage ranges (0 V to 5 V, 0 V to 10 V, ±10 V, ±5 V, ±2.5 V, and -2.5 V to +7.5 V) can be selected using software or pin-strapping, eliminating the need to add precision gain stages and allowing customers to improve production logistics and adjust inventory mix on the fly.

The current-mode output enables users to choose their own external amplifier to optimize speed, accuracy, noise, power, or other parameters, and allows the voltage output to swing beyond the DAC supply rails. Alternative 18-bit DACs with internal amplifiers cannot swing beyond 0 V to 5 V and limit the output near the supply rails.

The LTC2757 uses a bidirectional parallel input/output interface that allows readback of any internal register, as well as the DAC output span setting. Voltage controlled offset and gain adjustment pins enable users to null system offset, gain error, or reference errors.

Availability

The LTC2757 DAC is available today in a 7 mm x 7 mm 48-pin LQFP package. Pricing begins at $25.50 each in 1,000-piece quantities.

Summary of Features: LTC2757

  • 18-bit ±1LSB INL, ±1LSB DNL Over Temperature
  • Guaranteed Linearity for Six Software Programmable
  • Output Ranges:

    – Unipolar 0 V to +5 V, 0 V to +10 V
    – Bipolar ±10 V, ±5 V, ±2.5 V, -2.5 to +7.5 V

  • Guaranteed Monotonic Over Temperature
  • Low 1 μA(max) Supply Current
  • Low 1.4 nV.s Glitch Impulse
  • 18-bit Settling Time: 2.1 μs
  • 2.7 V to 5.5 V Single Supply Operation
  • Voltage Controlled Offset and Gain Trims
  • Parallel Interface with Readback of All Registers
  • Clear and Power-On Reset to 0V Regardless of
  • Output Range

  • 48-Pin 7 mm x 7 mm LQFP Package

Datasheet:

LTC2757

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