AD9761ARS

双10位通道TxDAC + ⑩ 2倍插值滤波器 Dual 10-Bit TxDAC+⑩ with 2x Interpolation Filters

Product Details

The AD9761 is a complete dual channel, high speed, 10-bit CMOS DAC. The AD9761 has been developed specifically for use in wide bandwidth communication applications e.g., spread spectrum where digital I and Q information is being processed during transmit operations. It integrates two 10-bit, 40 MSPS DACs, dual 2x interpolation filters, a voltage reference, and digital input interface circuitry. The AD9761 supports a 20 MSPS per channel input data rate that is then interpolated by 2x up to 40 MSPS before simultaneously updating each DAC.

The interleaved I and Q input data stream is presented to the digital interface circuitry, which consists of I and Q latches as well as some additional control logic. The data is de-interleaved back into its original I and Q data. An on-chip state machine ensures the proper pairing of I and Q data. The data output from each latch is then processed by a 2x digital interpolation filter that eases the reconstruction filter requirements. The interpolated output of each filter serves as the input of their respective 10-bit DAC.

The DACs utilize a segmented current source architecture combined with a proprietary switching technique to reduce glitch energy and to maximize dynamic accuracy. Each DAC provides differential current output thus supporting single-ended or differential applications. Both DACs are simultaneously updated and provide a nominal full-scale current of 10 mA. Also, the full-scale currents between each DAC are matched to within 0.07 dB i.e., 0.75%, thus eliminating the need for additional gain calibration circuitry.

The AD9761 is manufactured on an advanced low cost CMOS process. It operates from a single supply of 2.7 V to 5.5 V and consumes 200 mW of power. To make the AD9761 complete it also offers an internal 1.20 V temperature-compensated bandgap reference.

### Features and Benefits

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Complete 10-Bit, 40 MSPS Dual Transmit DAC

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Excellent Gain and Offset Matching

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Differential Nonlinearity Error: 0.5 LSB

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Effective Numbe of Bits: 9.5

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Signal-to-Noise and Distortion Ratio: 59 dB

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Spurious-Free Dynamic Range: 71 dB

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2x Interpolation Filters

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20 MSPS/Channel Data Rate

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Single Supply: 3V to 5.5 V

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Low Power Dissipation: 93 mW

3 V Supply @ 40 MSPS

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On-Chip Reference

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28-Lead SSOP